library.LLVMInitializeAnalysis.argtypes = [PassRegistry]
library.LLVMInitializeAnalysis.restype = None
- library.LLVMInitializeIPA.argtypes = [PassRegistry]
- library.LLVMInitializeIPA.restype = None
-
library.LLVMInitializeCodeGen.argtypes = [PassRegistry]
library.LLVMInitializeCodeGen.restype = None
lib.LLVMInitializeIPO(p)
lib.LLVMInitializeInstrumentation(p)
lib.LLVMInitializeAnalysis(p)
- lib.LLVMInitializeIPA(p)
lib.LLVMInitializeCodeGen(p)
lib.LLVMInitializeTarget(p)
/// initializeAnalysis - Initialize all passes linked into the Analysis library.
void initializeAnalysis(PassRegistry&);
-/// initializeIPA - Initialize all passes linked into the IPA library.
-void initializeIPA(PassRegistry&);
-
/// initializeCodeGen - Initialize all passes linked into the CodeGen library.
void initializeCodeGen(PassRegistry&);
initializeBasicAliasAnalysisPass(Registry);
initializeBlockFrequencyInfoWrapperPassPass(Registry);
initializeBranchProbabilityInfoWrapperPassPass(Registry);
+ initializeCallGraphWrapperPassPass(Registry);
+ initializeCallGraphPrinterPass(Registry);
+ initializeCallGraphViewerPass(Registry);
initializeCostModelAnalysisPass(Registry);
initializeCFGViewerPass(Registry);
initializeCFGPrinterPass(Registry);
initializePostDomPrinterPass(Registry);
initializePostDomOnlyViewerPass(Registry);
initializePostDomOnlyPrinterPass(Registry);
+ initializeGlobalsModRefPass(Registry);
initializeIVUsersPass(Registry);
initializeInstCountPass(Registry);
initializeIntervalPartitionPass(Registry);
initializeAnalysis(*unwrap(R));
}
+void LLVMInitializeIPA(LLVMPassRegistryRef R) {
+ initializeAnalysis(*unwrap(R));
+}
+
LLVMBool LLVMVerifyModule(LLVMModuleRef M, LLVMVerifierFailureAction Action,
char **OutMessages) {
raw_ostream *DebugOS = Action != LLVMReturnStatusAction ? &errs() : nullptr;
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp
+ CallGraph.cpp
+ CallGraphSCCPass.cpp
+ CallPrinter.cpp
CaptureTracking.cpp
CostModel.cpp
CodeMetrics.cpp
DivergenceAnalysis.cpp
DomPrinter.cpp
DominanceFrontier.cpp
+ GlobalsModRef.cpp
IVUsers.cpp
+ InlineCost.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
)
add_dependencies(LLVMAnalysis intrinsics_gen)
-
-add_subdirectory(IPA)
--- /dev/null
+//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraph class methods.
+//
+
+CallGraph::CallGraph(Module &M)
+ : M(M), Root(nullptr), ExternalCallingNode(getOrInsertFunction(nullptr)),
+ CallsExternalNode(llvm::make_unique<CallGraphNode>(nullptr)) {
+ // Add every function to the call graph.
+ for (Function &F : M)
+ addToCallGraph(&F);
+
+ // If we didn't find a main function, use the external call graph node
+ if (!Root)
+ Root = ExternalCallingNode;
+}
+
+CallGraph::CallGraph(CallGraph &&Arg)
+ : M(Arg.M), FunctionMap(std::move(Arg.FunctionMap)), Root(Arg.Root),
+ ExternalCallingNode(Arg.ExternalCallingNode),
+ CallsExternalNode(std::move(Arg.CallsExternalNode)) {
+ Arg.FunctionMap.clear();
+ Arg.Root = nullptr;
+ Arg.ExternalCallingNode = nullptr;
+}
+
+CallGraph::~CallGraph() {
+ // CallsExternalNode is not in the function map, delete it explicitly.
+ if (CallsExternalNode)
+ CallsExternalNode->allReferencesDropped();
+
+// Reset all node's use counts to zero before deleting them to prevent an
+// assertion from firing.
+#ifndef NDEBUG
+ for (auto &I : FunctionMap)
+ I.second->allReferencesDropped();
+#endif
+}
+
+void CallGraph::addToCallGraph(Function *F) {
+ CallGraphNode *Node = getOrInsertFunction(F);
+
+ // If this function has external linkage, anything could call it.
+ if (!F->hasLocalLinkage()) {
+ ExternalCallingNode->addCalledFunction(CallSite(), Node);
+
+ // Found the entry point?
+ if (F->getName() == "main") {
+ if (Root) // Found multiple external mains? Don't pick one.
+ Root = ExternalCallingNode;
+ else
+ Root = Node; // Found a main, keep track of it!
+ }
+ }
+
+ // If this function has its address taken, anything could call it.
+ if (F->hasAddressTaken())
+ ExternalCallingNode->addCalledFunction(CallSite(), Node);
+
+ // If this function is not defined in this translation unit, it could call
+ // anything.
+ if (F->isDeclaration() && !F->isIntrinsic())
+ Node->addCalledFunction(CallSite(), CallsExternalNode.get());
+
+ // Look for calls by this function.
+ for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
+ for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;
+ ++II) {
+ CallSite CS(cast<Value>(II));
+ if (CS) {
+ const Function *Callee = CS.getCalledFunction();
+ if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
+ // Indirect calls of intrinsics are not allowed so no need to check.
+ // We can be more precise here by using TargetArg returned by
+ // Intrinsic::isLeaf.
+ Node->addCalledFunction(CS, CallsExternalNode.get());
+ else if (!Callee->isIntrinsic())
+ Node->addCalledFunction(CS, getOrInsertFunction(Callee));
+ }
+ }
+}
+
+void CallGraph::print(raw_ostream &OS) const {
+ OS << "CallGraph Root is: ";
+ if (Function *F = Root->getFunction())
+ OS << F->getName() << "\n";
+ else {
+ OS << "<<null function: 0x" << Root << ">>\n";
+ }
+
+ // Print in a deterministic order by sorting CallGraphNodes by name. We do
+ // this here to avoid slowing down the non-printing fast path.
+
+ SmallVector<CallGraphNode *, 16> Nodes;
+ Nodes.reserve(FunctionMap.size());
+
+ for (auto I = begin(), E = end(); I != E; ++I)
+ Nodes.push_back(I->second.get());
+
+ std::sort(Nodes.begin(), Nodes.end(),
+ [](CallGraphNode *LHS, CallGraphNode *RHS) {
+ if (Function *LF = LHS->getFunction())
+ if (Function *RF = RHS->getFunction())
+ return LF->getName() < RF->getName();
+
+ return RHS->getFunction() != nullptr;
+ });
+
+ for (CallGraphNode *CN : Nodes)
+ CN->print(OS);
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraph::dump() const { print(dbgs()); }
+#endif
+
+// removeFunctionFromModule - Unlink the function from this module, returning
+// it. Because this removes the function from the module, the call graph node
+// is destroyed. This is only valid if the function does not call any other
+// functions (ie, there are no edges in it's CGN). The easiest way to do this
+// is to dropAllReferences before calling this.
+//
+Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
+ assert(CGN->empty() && "Cannot remove function from call "
+ "graph if it references other functions!");
+ Function *F = CGN->getFunction(); // Get the function for the call graph node
+ FunctionMap.erase(F); // Remove the call graph node from the map
+
+ M.getFunctionList().remove(F);
+ return F;
+}
+
+/// spliceFunction - Replace the function represented by this node by another.
+/// This does not rescan the body of the function, so it is suitable when
+/// splicing the body of the old function to the new while also updating all
+/// callers from old to new.
+///
+void CallGraph::spliceFunction(const Function *From, const Function *To) {
+ assert(FunctionMap.count(From) && "No CallGraphNode for function!");
+ assert(!FunctionMap.count(To) &&
+ "Pointing CallGraphNode at a function that already exists");
+ FunctionMapTy::iterator I = FunctionMap.find(From);
+ I->second->F = const_cast<Function*>(To);
+ FunctionMap[To] = std::move(I->second);
+ FunctionMap.erase(I);
+}
+
+// getOrInsertFunction - This method is identical to calling operator[], but
+// it will insert a new CallGraphNode for the specified function if one does
+// not already exist.
+CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
+ auto &CGN = FunctionMap[F];
+ if (CGN)
+ return CGN.get();
+
+ assert((!F || F->getParent() == &M) && "Function not in current module!");
+ CGN = llvm::make_unique<CallGraphNode>(const_cast<Function *>(F));
+ return CGN.get();
+}
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraphNode class methods.
+//
+
+void CallGraphNode::print(raw_ostream &OS) const {
+ if (Function *F = getFunction())
+ OS << "Call graph node for function: '" << F->getName() << "'";
+ else
+ OS << "Call graph node <<null function>>";
+
+ OS << "<<" << this << ">> #uses=" << getNumReferences() << '\n';
+
+ for (const_iterator I = begin(), E = end(); I != E; ++I) {
+ OS << " CS<" << I->first << "> calls ";
+ if (Function *FI = I->second->getFunction())
+ OS << "function '" << FI->getName() <<"'\n";
+ else
+ OS << "external node\n";
+ }
+ OS << '\n';
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraphNode::dump() const { print(dbgs()); }
+#endif
+
+/// removeCallEdgeFor - This method removes the edge in the node for the
+/// specified call site. Note that this method takes linear time, so it
+/// should be used sparingly.
+void CallGraphNode::removeCallEdgeFor(CallSite CS) {
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first == CS.getInstruction()) {
+ I->second->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ return;
+ }
+ }
+}
+
+// removeAnyCallEdgeTo - This method removes any call edges from this node to
+// the specified callee function. This takes more time to execute than
+// removeCallEdgeTo, so it should not be used unless necessary.
+void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
+ for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
+ if (CalledFunctions[i].second == Callee) {
+ Callee->DropRef();
+ CalledFunctions[i] = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ --i; --e;
+ }
+}
+
+/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
+/// from this node to the specified callee function.
+void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
+ CallRecord &CR = *I;
+ if (CR.second == Callee && CR.first == nullptr) {
+ Callee->DropRef();
+ *I = CalledFunctions.back();
+ CalledFunctions.pop_back();
+ return;
+ }
+ }
+}
+
+/// replaceCallEdge - This method replaces the edge in the node for the
+/// specified call site with a new one. Note that this method takes linear
+/// time, so it should be used sparingly.
+void CallGraphNode::replaceCallEdge(CallSite CS,
+ CallSite NewCS, CallGraphNode *NewNode){
+ for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
+ assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
+ if (I->first == CS.getInstruction()) {
+ I->second->DropRef();
+ I->first = NewCS.getInstruction();
+ I->second = NewNode;
+ NewNode->AddRef();
+ return;
+ }
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Out-of-line definitions of CallGraphAnalysis class members.
+//
+
+char CallGraphAnalysis::PassID;
+
+//===----------------------------------------------------------------------===//
+// Implementations of the CallGraphWrapperPass class methods.
+//
+
+CallGraphWrapperPass::CallGraphWrapperPass() : ModulePass(ID) {
+ initializeCallGraphWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+CallGraphWrapperPass::~CallGraphWrapperPass() {}
+
+void CallGraphWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+}
+
+bool CallGraphWrapperPass::runOnModule(Module &M) {
+ // All the real work is done in the constructor for the CallGraph.
+ G.reset(new CallGraph(M));
+ return false;
+}
+
+INITIALIZE_PASS(CallGraphWrapperPass, "basiccg", "CallGraph Construction",
+ false, true)
+
+char CallGraphWrapperPass::ID = 0;
+
+void CallGraphWrapperPass::releaseMemory() { G.reset(); }
+
+void CallGraphWrapperPass::print(raw_ostream &OS, const Module *) const {
+ if (!G) {
+ OS << "No call graph has been built!\n";
+ return;
+ }
+
+ // Just delegate.
+ G->print(OS);
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void CallGraphWrapperPass::dump() const { print(dbgs(), nullptr); }
+#endif
--- /dev/null
+//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the CallGraphSCCPass class, which is used for passes
+// which are implemented as bottom-up traversals on the call graph. Because
+// there may be cycles in the call graph, passes of this type operate on the
+// call-graph in SCC order: that is, they process function bottom-up, except for
+// recursive functions, which they process all at once.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/LegacyPassManagers.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "cgscc-passmgr"
+
+static cl::opt<unsigned>
+MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4));
+
+STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");
+
+//===----------------------------------------------------------------------===//
+// CGPassManager
+//
+/// CGPassManager manages FPPassManagers and CallGraphSCCPasses.
+
+namespace {
+
+class CGPassManager : public ModulePass, public PMDataManager {
+public:
+ static char ID;
+ explicit CGPassManager()
+ : ModulePass(ID), PMDataManager() { }
+
+ /// Execute all of the passes scheduled for execution. Keep track of
+ /// whether any of the passes modifies the module, and if so, return true.
+ bool runOnModule(Module &M) override;
+
+ using ModulePass::doInitialization;
+ using ModulePass::doFinalization;
+
+ bool doInitialization(CallGraph &CG);
+ bool doFinalization(CallGraph &CG);
+
+ /// Pass Manager itself does not invalidate any analysis info.
+ void getAnalysisUsage(AnalysisUsage &Info) const override {
+ // CGPassManager walks SCC and it needs CallGraph.
+ Info.addRequired<CallGraphWrapperPass>();
+ Info.setPreservesAll();
+ }
+
+ const char *getPassName() const override {
+ return "CallGraph Pass Manager";
+ }
+
+ PMDataManager *getAsPMDataManager() override { return this; }
+ Pass *getAsPass() override { return this; }
+
+ // Print passes managed by this manager
+ void dumpPassStructure(unsigned Offset) override {
+ errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";
+ for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
+ Pass *P = getContainedPass(Index);
+ P->dumpPassStructure(Offset + 1);
+ dumpLastUses(P, Offset+1);
+ }
+ }
+
+ Pass *getContainedPass(unsigned N) {
+ assert(N < PassVector.size() && "Pass number out of range!");
+ return static_cast<Pass *>(PassVector[N]);
+ }
+
+ PassManagerType getPassManagerType() const override {
+ return PMT_CallGraphPassManager;
+ }
+
+private:
+ bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
+ bool &DevirtualizedCall);
+
+ bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
+ CallGraph &CG, bool &CallGraphUpToDate,
+ bool &DevirtualizedCall);
+ bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG,
+ bool IsCheckingMode);
+};
+
+} // end anonymous namespace.
+
+char CGPassManager::ID = 0;
+
+
+bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
+ CallGraph &CG, bool &CallGraphUpToDate,
+ bool &DevirtualizedCall) {
+ bool Changed = false;
+ PMDataManager *PM = P->getAsPMDataManager();
+
+ if (!PM) {
+ CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P;
+ if (!CallGraphUpToDate) {
+ DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
+ CallGraphUpToDate = true;
+ }
+
+ {
+ TimeRegion PassTimer(getPassTimer(CGSP));
+ Changed = CGSP->runOnSCC(CurSCC);
+ }
+
+ // After the CGSCCPass is done, when assertions are enabled, use
+ // RefreshCallGraph to verify that the callgraph was correctly updated.
+#ifndef NDEBUG
+ if (Changed)
+ RefreshCallGraph(CurSCC, CG, true);
+#endif
+
+ return Changed;
+ }
+
+
+ assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+ "Invalid CGPassManager member");
+ FPPassManager *FPP = (FPPassManager*)P;
+
+ // Run pass P on all functions in the current SCC.
+ for (CallGraphNode *CGN : CurSCC) {
+ if (Function *F = CGN->getFunction()) {
+ dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
+ {
+ TimeRegion PassTimer(getPassTimer(FPP));
+ Changed |= FPP->runOnFunction(*F);
+ }
+ F->getContext().yield();
+ }
+ }
+
+ // The function pass(es) modified the IR, they may have clobbered the
+ // callgraph.
+ if (Changed && CallGraphUpToDate) {
+ DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: "
+ << P->getPassName() << '\n');
+ CallGraphUpToDate = false;
+ }
+ return Changed;
+}
+
+
+/// Scan the functions in the specified CFG and resync the
+/// callgraph with the call sites found in it. This is used after
+/// FunctionPasses have potentially munged the callgraph, and can be used after
+/// CallGraphSCC passes to verify that they correctly updated the callgraph.
+///
+/// This function returns true if it devirtualized an existing function call,
+/// meaning it turned an indirect call into a direct call. This happens when
+/// a function pass like GVN optimizes away stuff feeding the indirect call.
+/// This never happens in checking mode.
+///
+bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
+ CallGraph &CG, bool CheckingMode) {
+ DenseMap<Value*, CallGraphNode*> CallSites;
+
+ DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
+ << " nodes:\n";
+ for (CallGraphNode *CGN : CurSCC)
+ CGN->dump();
+ );
+
+ bool MadeChange = false;
+ bool DevirtualizedCall = false;
+
+ // Scan all functions in the SCC.
+ unsigned FunctionNo = 0;
+ for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();
+ SCCIdx != E; ++SCCIdx, ++FunctionNo) {
+ CallGraphNode *CGN = *SCCIdx;
+ Function *F = CGN->getFunction();
+ if (!F || F->isDeclaration()) continue;
+
+ // Walk the function body looking for call sites. Sync up the call sites in
+ // CGN with those actually in the function.
+
+ // Keep track of the number of direct and indirect calls that were
+ // invalidated and removed.
+ unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;
+
+ // Get the set of call sites currently in the function.
+ for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) {
+ // If this call site is null, then the function pass deleted the call
+ // entirely and the WeakVH nulled it out.
+ if (!I->first ||
+ // If we've already seen this call site, then the FunctionPass RAUW'd
+ // one call with another, which resulted in two "uses" in the edge
+ // list of the same call.
+ CallSites.count(I->first) ||
+
+ // If the call edge is not from a call or invoke, or it is a
+ // instrinsic call, then the function pass RAUW'd a call with
+ // another value. This can happen when constant folding happens
+ // of well known functions etc.
+ !CallSite(I->first) ||
+ (CallSite(I->first).getCalledFunction() &&
+ CallSite(I->first).getCalledFunction()->isIntrinsic() &&
+ Intrinsic::isLeaf(
+ CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
+ assert(!CheckingMode &&
+ "CallGraphSCCPass did not update the CallGraph correctly!");
+
+ // If this was an indirect call site, count it.
+ if (!I->second->getFunction())
+ ++NumIndirectRemoved;
+ else
+ ++NumDirectRemoved;
+
+ // Just remove the edge from the set of callees, keep track of whether
+ // I points to the last element of the vector.
+ bool WasLast = I + 1 == E;
+ CGN->removeCallEdge(I);
+
+ // If I pointed to the last element of the vector, we have to bail out:
+ // iterator checking rejects comparisons of the resultant pointer with
+ // end.
+ if (WasLast)
+ break;
+ E = CGN->end();
+ continue;
+ }
+
+ assert(!CallSites.count(I->first) &&
+ "Call site occurs in node multiple times");
+
+ CallSite CS(I->first);
+ if (CS) {
+ Function *Callee = CS.getCalledFunction();
+ // Ignore intrinsics because they're not really function calls.
+ if (!Callee || !(Callee->isIntrinsic()))
+ CallSites.insert(std::make_pair(I->first, I->second));
+ }
+ ++I;
+ }
+
+ // Loop over all of the instructions in the function, getting the callsites.
+ // Keep track of the number of direct/indirect calls added.
+ unsigned NumDirectAdded = 0, NumIndirectAdded = 0;
+
+ for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ CallSite CS(cast<Value>(I));
+ if (!CS) continue;
+ Function *Callee = CS.getCalledFunction();
+ if (Callee && Callee->isIntrinsic()) continue;
+
+ // If this call site already existed in the callgraph, just verify it
+ // matches up to expectations and remove it from CallSites.
+ DenseMap<Value*, CallGraphNode*>::iterator ExistingIt =
+ CallSites.find(CS.getInstruction());
+ if (ExistingIt != CallSites.end()) {
+ CallGraphNode *ExistingNode = ExistingIt->second;
+
+ // Remove from CallSites since we have now seen it.
+ CallSites.erase(ExistingIt);
+
+ // Verify that the callee is right.
+ if (ExistingNode->getFunction() == CS.getCalledFunction())
+ continue;
+
+ // If we are in checking mode, we are not allowed to actually mutate
+ // the callgraph. If this is a case where we can infer that the
+ // callgraph is less precise than it could be (e.g. an indirect call
+ // site could be turned direct), don't reject it in checking mode, and
+ // don't tweak it to be more precise.
+ if (CheckingMode && CS.getCalledFunction() &&
+ ExistingNode->getFunction() == nullptr)
+ continue;
+
+ assert(!CheckingMode &&
+ "CallGraphSCCPass did not update the CallGraph correctly!");
+
+ // If not, we either went from a direct call to indirect, indirect to
+ // direct, or direct to different direct.
+ CallGraphNode *CalleeNode;
+ if (Function *Callee = CS.getCalledFunction()) {
+ CalleeNode = CG.getOrInsertFunction(Callee);
+ // Keep track of whether we turned an indirect call into a direct
+ // one.
+ if (!ExistingNode->getFunction()) {
+ DevirtualizedCall = true;
+ DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '"
+ << Callee->getName() << "'\n");
+ }
+ } else {
+ CalleeNode = CG.getCallsExternalNode();
+ }
+
+ // Update the edge target in CGN.
+ CGN->replaceCallEdge(CS, CS, CalleeNode);
+ MadeChange = true;
+ continue;
+ }
+
+ assert(!CheckingMode &&
+ "CallGraphSCCPass did not update the CallGraph correctly!");
+
+ // If the call site didn't exist in the CGN yet, add it.
+ CallGraphNode *CalleeNode;
+ if (Function *Callee = CS.getCalledFunction()) {
+ CalleeNode = CG.getOrInsertFunction(Callee);
+ ++NumDirectAdded;
+ } else {
+ CalleeNode = CG.getCallsExternalNode();
+ ++NumIndirectAdded;
+ }
+
+ CGN->addCalledFunction(CS, CalleeNode);
+ MadeChange = true;
+ }
+
+ // We scanned the old callgraph node, removing invalidated call sites and
+ // then added back newly found call sites. One thing that can happen is
+ // that an old indirect call site was deleted and replaced with a new direct
+ // call. In this case, we have devirtualized a call, and CGSCCPM would like
+ // to iteratively optimize the new code. Unfortunately, we don't really
+ // have a great way to detect when this happens. As an approximation, we
+ // just look at whether the number of indirect calls is reduced and the
+ // number of direct calls is increased. There are tons of ways to fool this
+ // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a
+ // direct call) but this is close enough.
+ if (NumIndirectRemoved > NumIndirectAdded &&
+ NumDirectRemoved < NumDirectAdded)
+ DevirtualizedCall = true;
+
+ // After scanning this function, if we still have entries in callsites, then
+ // they are dangling pointers. WeakVH should save us for this, so abort if
+ // this happens.
+ assert(CallSites.empty() && "Dangling pointers found in call sites map");
+
+ // Periodically do an explicit clear to remove tombstones when processing
+ // large scc's.
+ if ((FunctionNo & 15) == 15)
+ CallSites.clear();
+ }
+
+ DEBUG(if (MadeChange) {
+ dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
+ for (CallGraphNode *CGN : CurSCC)
+ CGN->dump();
+ if (DevirtualizedCall)
+ dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";
+
+ } else {
+ dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
+ }
+ );
+ (void)MadeChange;
+
+ return DevirtualizedCall;
+}
+
+/// Execute the body of the entire pass manager on the specified SCC.
+/// This keeps track of whether a function pass devirtualizes
+/// any calls and returns it in DevirtualizedCall.
+bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
+ bool &DevirtualizedCall) {
+ bool Changed = false;
+
+ // Keep track of whether the callgraph is known to be up-to-date or not.
+ // The CGSSC pass manager runs two types of passes:
+ // CallGraphSCC Passes and other random function passes. Because other
+ // random function passes are not CallGraph aware, they may clobber the
+ // call graph by introducing new calls or deleting other ones. This flag
+ // is set to false when we run a function pass so that we know to clean up
+ // the callgraph when we need to run a CGSCCPass again.
+ bool CallGraphUpToDate = true;
+
+ // Run all passes on current SCC.
+ for (unsigned PassNo = 0, e = getNumContainedPasses();
+ PassNo != e; ++PassNo) {
+ Pass *P = getContainedPass(PassNo);
+
+ // If we're in -debug-pass=Executions mode, construct the SCC node list,
+ // otherwise avoid constructing this string as it is expensive.
+ if (isPassDebuggingExecutionsOrMore()) {
+ std::string Functions;
+ #ifndef NDEBUG
+ raw_string_ostream OS(Functions);
+ for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end();
+ I != E; ++I) {
+ if (I != CurSCC.begin()) OS << ", ";
+ (*I)->print(OS);
+ }
+ OS.flush();
+ #endif
+ dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
+ }
+ dumpRequiredSet(P);
+
+ initializeAnalysisImpl(P);
+
+ // Actually run this pass on the current SCC.
+ Changed |= RunPassOnSCC(P, CurSCC, CG,
+ CallGraphUpToDate, DevirtualizedCall);
+
+ if (Changed)
+ dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
+ dumpPreservedSet(P);
+
+ verifyPreservedAnalysis(P);
+ removeNotPreservedAnalysis(P);
+ recordAvailableAnalysis(P);
+ removeDeadPasses(P, "", ON_CG_MSG);
+ }
+
+ // If the callgraph was left out of date (because the last pass run was a
+ // functionpass), refresh it before we move on to the next SCC.
+ if (!CallGraphUpToDate)
+ DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
+ return Changed;
+}
+
+/// Execute all of the passes scheduled for execution. Keep track of
+/// whether any of the passes modifies the module, and if so, return true.
+bool CGPassManager::runOnModule(Module &M) {
+ CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+ bool Changed = doInitialization(CG);
+
+ // Walk the callgraph in bottom-up SCC order.
+ scc_iterator<CallGraph*> CGI = scc_begin(&CG);
+
+ CallGraphSCC CurSCC(&CGI);
+ while (!CGI.isAtEnd()) {
+ // Copy the current SCC and increment past it so that the pass can hack
+ // on the SCC if it wants to without invalidating our iterator.
+ const std::vector<CallGraphNode *> &NodeVec = *CGI;
+ CurSCC.initialize(NodeVec.data(), NodeVec.data() + NodeVec.size());
+ ++CGI;
+
+ // At the top level, we run all the passes in this pass manager on the
+ // functions in this SCC. However, we support iterative compilation in the
+ // case where a function pass devirtualizes a call to a function. For
+ // example, it is very common for a function pass (often GVN or instcombine)
+ // to eliminate the addressing that feeds into a call. With that improved
+ // information, we would like the call to be an inline candidate, infer
+ // mod-ref information etc.
+ //
+ // Because of this, we allow iteration up to a specified iteration count.
+ // This only happens in the case of a devirtualized call, so we only burn
+ // compile time in the case that we're making progress. We also have a hard
+ // iteration count limit in case there is crazy code.
+ unsigned Iteration = 0;
+ bool DevirtualizedCall = false;
+ do {
+ DEBUG(if (Iteration)
+ dbgs() << " SCCPASSMGR: Re-visiting SCC, iteration #"
+ << Iteration << '\n');
+ DevirtualizedCall = false;
+ Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
+ } while (Iteration++ < MaxIterations && DevirtualizedCall);
+
+ if (DevirtualizedCall)
+ DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after " << Iteration
+ << " times, due to -max-cg-scc-iterations\n");
+
+ if (Iteration > MaxSCCIterations)
+ MaxSCCIterations = Iteration;
+
+ }
+ Changed |= doFinalization(CG);
+ return Changed;
+}
+
+
+/// Initialize CG
+bool CGPassManager::doInitialization(CallGraph &CG) {
+ bool Changed = false;
+ for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
+ if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
+ assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+ "Invalid CGPassManager member");
+ Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());
+ } else {
+ Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);
+ }
+ }
+ return Changed;
+}
+
+/// Finalize CG
+bool CGPassManager::doFinalization(CallGraph &CG) {
+ bool Changed = false;
+ for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
+ if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
+ assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
+ "Invalid CGPassManager member");
+ Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());
+ } else {
+ Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);
+ }
+ }
+ return Changed;
+}
+
+//===----------------------------------------------------------------------===//
+// CallGraphSCC Implementation
+//===----------------------------------------------------------------------===//
+
+/// This informs the SCC and the pass manager that the specified
+/// Old node has been deleted, and New is to be used in its place.
+void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {
+ assert(Old != New && "Should not replace node with self");
+ for (unsigned i = 0; ; ++i) {
+ assert(i != Nodes.size() && "Node not in SCC");
+ if (Nodes[i] != Old) continue;
+ Nodes[i] = New;
+ break;
+ }
+
+ // Update the active scc_iterator so that it doesn't contain dangling
+ // pointers to the old CallGraphNode.
+ scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
+ CGI->ReplaceNode(Old, New);
+}
+
+
+//===----------------------------------------------------------------------===//
+// CallGraphSCCPass Implementation
+//===----------------------------------------------------------------------===//
+
+/// Assign pass manager to manage this pass.
+void CallGraphSCCPass::assignPassManager(PMStack &PMS,
+ PassManagerType PreferredType) {
+ // Find CGPassManager
+ while (!PMS.empty() &&
+ PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
+ PMS.pop();
+
+ assert(!PMS.empty() && "Unable to handle Call Graph Pass");
+ CGPassManager *CGP;
+
+ if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)
+ CGP = (CGPassManager*)PMS.top();
+ else {
+ // Create new Call Graph SCC Pass Manager if it does not exist.
+ assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");
+ PMDataManager *PMD = PMS.top();
+
+ // [1] Create new Call Graph Pass Manager
+ CGP = new CGPassManager();
+
+ // [2] Set up new manager's top level manager
+ PMTopLevelManager *TPM = PMD->getTopLevelManager();
+ TPM->addIndirectPassManager(CGP);
+
+ // [3] Assign manager to manage this new manager. This may create
+ // and push new managers into PMS
+ Pass *P = CGP;
+ TPM->schedulePass(P);
+
+ // [4] Push new manager into PMS
+ PMS.push(CGP);
+ }
+
+ CGP->add(this);
+}
+
+/// For this class, we declare that we require and preserve the call graph.
+/// If the derived class implements this method, it should
+/// always explicitly call the implementation here.
+void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<CallGraphWrapperPass>();
+ AU.addPreserved<CallGraphWrapperPass>();
+}
+
+
+//===----------------------------------------------------------------------===//
+// PrintCallGraphPass Implementation
+//===----------------------------------------------------------------------===//
+
+namespace {
+ /// PrintCallGraphPass - Print a Module corresponding to a call graph.
+ ///
+ class PrintCallGraphPass : public CallGraphSCCPass {
+ std::string Banner;
+ raw_ostream &Out; // raw_ostream to print on.
+
+ public:
+ static char ID;
+ PrintCallGraphPass(const std::string &B, raw_ostream &o)
+ : CallGraphSCCPass(ID), Banner(B), Out(o) {}
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.setPreservesAll();
+ }
+
+ bool runOnSCC(CallGraphSCC &SCC) override {
+ Out << Banner;
+ for (CallGraphNode *CGN : SCC) {
+ if (CGN->getFunction())
+ CGN->getFunction()->print(Out);
+ else
+ Out << "\nPrinting <null> Function\n";
+ }
+ return false;
+ }
+ };
+
+} // end anonymous namespace.
+
+char PrintCallGraphPass::ID = 0;
+
+Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const {
+ return new PrintCallGraphPass(Banner, O);
+}
+
--- /dev/null
+//===- CallPrinter.cpp - DOT printer for call graph -----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines '-dot-callgraph', which emit a callgraph.<fnname>.dot
+// containing the call graph of a module.
+//
+// There is also a pass available to directly call dotty ('-view-callgraph').
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/CallPrinter.h"
+#include "llvm/Analysis/DOTGraphTraitsPass.h"
+
+using namespace llvm;
+
+namespace llvm {
+
+template <> struct DOTGraphTraits<CallGraph *> : public DefaultDOTGraphTraits {
+ DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
+
+ static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
+
+ std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
+ if (Function *Func = Node->getFunction())
+ return Func->getName();
+
+ return "external node";
+ }
+};
+
+struct AnalysisCallGraphWrapperPassTraits {
+ static CallGraph *getGraph(CallGraphWrapperPass *P) {
+ return &P->getCallGraph();
+ }
+};
+
+} // end llvm namespace
+
+namespace {
+
+struct CallGraphViewer
+ : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
+ AnalysisCallGraphWrapperPassTraits> {
+ static char ID;
+
+ CallGraphViewer()
+ : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
+ AnalysisCallGraphWrapperPassTraits>(
+ "callgraph", ID) {
+ initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
+ }
+};
+
+struct CallGraphPrinter : public DOTGraphTraitsModulePrinter<
+ CallGraphWrapperPass, true, CallGraph *,
+ AnalysisCallGraphWrapperPassTraits> {
+ static char ID;
+
+ CallGraphPrinter()
+ : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
+ AnalysisCallGraphWrapperPassTraits>(
+ "callgraph", ID) {
+ initializeCallGraphPrinterPass(*PassRegistry::getPassRegistry());
+ }
+};
+
+} // end anonymous namespace
+
+char CallGraphViewer::ID = 0;
+INITIALIZE_PASS(CallGraphViewer, "view-callgraph", "View call graph", false,
+ false)
+
+char CallGraphPrinter::ID = 0;
+INITIALIZE_PASS(CallGraphPrinter, "dot-callgraph",
+ "Print call graph to 'dot' file", false, false)
+
+// Create methods available outside of this file, to use them
+// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
+// the link time optimization.
+
+ModulePass *llvm::createCallGraphViewerPass() { return new CallGraphViewer(); }
+
+ModulePass *llvm::createCallGraphPrinterPass() {
+ return new CallGraphPrinter();
+}
--- /dev/null
+//===- GlobalsModRef.cpp - Simple Mod/Ref Analysis for Globals ------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This simple pass provides alias and mod/ref information for global values
+// that do not have their address taken, and keeps track of whether functions
+// read or write memory (are "pure"). For this simple (but very common) case,
+// we can provide pretty accurate and useful information.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/ADT/SCCIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "globalsmodref-aa"
+
+STATISTIC(NumNonAddrTakenGlobalVars,
+ "Number of global vars without address taken");
+STATISTIC(NumNonAddrTakenFunctions,"Number of functions without address taken");
+STATISTIC(NumNoMemFunctions, "Number of functions that do not access memory");
+STATISTIC(NumReadMemFunctions, "Number of functions that only read memory");
+STATISTIC(NumIndirectGlobalVars, "Number of indirect global objects");
+
+// An option to enable unsafe alias results from the GlobalsModRef analysis.
+// When enabled, GlobalsModRef will provide no-alias results which in extremely
+// rare cases may not be conservatively correct. In particular, in the face of
+// transforms which cause assymetry between how effective GetUnderlyingObject
+// is for two pointers, it may produce incorrect results.
+//
+// These unsafe results have been returned by GMR for many years without
+// causing significant issues in the wild and so we provide a mechanism to
+// re-enable them for users of LLVM that have a particular performance
+// sensitivity and no known issues. The option also makes it easy to evaluate
+// the performance impact of these results.
+static cl::opt<bool> EnableUnsafeGlobalsModRefAliasResults(
+ "enable-unsafe-globalsmodref-alias-results", cl::init(false), cl::Hidden);
+
+/// The mod/ref information collected for a particular function.
+///
+/// We collect information about mod/ref behavior of a function here, both in
+/// general and as pertains to specific globals. We only have this detailed
+/// information when we know *something* useful about the behavior. If we
+/// saturate to fully general mod/ref, we remove the info for the function.
+class GlobalsModRef::FunctionInfo {
+ typedef SmallDenseMap<const GlobalValue *, ModRefInfo, 16> GlobalInfoMapType;
+
+ /// Build a wrapper struct that has 8-byte alignment. All heap allocations
+ /// should provide this much alignment at least, but this makes it clear we
+ /// specifically rely on this amount of alignment.
+ struct LLVM_ALIGNAS(8) AlignedMap {
+ AlignedMap() {}
+ AlignedMap(const AlignedMap &Arg) : Map(Arg.Map) {}
+ GlobalInfoMapType Map;
+ };
+
+ /// Pointer traits for our aligned map.
+ struct AlignedMapPointerTraits {
+ static inline void *getAsVoidPointer(AlignedMap *P) { return P; }
+ static inline AlignedMap *getFromVoidPointer(void *P) {
+ return (AlignedMap *)P;
+ }
+ enum { NumLowBitsAvailable = 3 };
+ static_assert(AlignOf<AlignedMap>::Alignment >= (1 << NumLowBitsAvailable),
+ "AlignedMap insufficiently aligned to have enough low bits.");
+ };
+
+ /// The bit that flags that this function may read any global. This is
+ /// chosen to mix together with ModRefInfo bits.
+ enum { MayReadAnyGlobal = 4 };
+
+ /// Checks to document the invariants of the bit packing here.
+ static_assert((MayReadAnyGlobal & MRI_ModRef) == 0,
+ "ModRef and the MayReadAnyGlobal flag bits overlap.");
+ static_assert(((MayReadAnyGlobal | MRI_ModRef) >>
+ AlignedMapPointerTraits::NumLowBitsAvailable) == 0,
+ "Insufficient low bits to store our flag and ModRef info.");
+
+public:
+ FunctionInfo() : Info() {}
+ ~FunctionInfo() {
+ delete Info.getPointer();
+ }
+ // Spell out the copy ond move constructors and assignment operators to get
+ // deep copy semantics and correct move semantics in the face of the
+ // pointer-int pair.
+ FunctionInfo(const FunctionInfo &Arg)
+ : Info(nullptr, Arg.Info.getInt()) {
+ if (const auto *ArgPtr = Arg.Info.getPointer())
+ Info.setPointer(new AlignedMap(*ArgPtr));
+ }
+ FunctionInfo(FunctionInfo &&Arg)
+ : Info(Arg.Info.getPointer(), Arg.Info.getInt()) {
+ Arg.Info.setPointerAndInt(nullptr, 0);
+ }
+ FunctionInfo &operator=(const FunctionInfo &RHS) {
+ delete Info.getPointer();
+ Info.setPointerAndInt(nullptr, RHS.Info.getInt());
+ if (const auto *RHSPtr = RHS.Info.getPointer())
+ Info.setPointer(new AlignedMap(*RHSPtr));
+ return *this;
+ }
+ FunctionInfo &operator=(FunctionInfo &&RHS) {
+ delete Info.getPointer();
+ Info.setPointerAndInt(RHS.Info.getPointer(), RHS.Info.getInt());
+ RHS.Info.setPointerAndInt(nullptr, 0);
+ return *this;
+ }
+
+ /// Returns the \c ModRefInfo info for this function.
+ ModRefInfo getModRefInfo() const {
+ return ModRefInfo(Info.getInt() & MRI_ModRef);
+ }
+
+ /// Adds new \c ModRefInfo for this function to its state.
+ void addModRefInfo(ModRefInfo NewMRI) {
+ Info.setInt(Info.getInt() | NewMRI);
+ }
+
+ /// Returns whether this function may read any global variable, and we don't
+ /// know which global.
+ bool mayReadAnyGlobal() const { return Info.getInt() & MayReadAnyGlobal; }
+
+ /// Sets this function as potentially reading from any global.
+ void setMayReadAnyGlobal() { Info.setInt(Info.getInt() | MayReadAnyGlobal); }
+
+ /// Returns the \c ModRefInfo info for this function w.r.t. a particular
+ /// global, which may be more precise than the general information above.
+ ModRefInfo getModRefInfoForGlobal(const GlobalValue &GV) const {
+ ModRefInfo GlobalMRI = mayReadAnyGlobal() ? MRI_Ref : MRI_NoModRef;
+ if (AlignedMap *P = Info.getPointer()) {
+ auto I = P->Map.find(&GV);
+ if (I != P->Map.end())
+ GlobalMRI = ModRefInfo(GlobalMRI | I->second);
+ }
+ return GlobalMRI;
+ }
+
+ /// Add mod/ref info from another function into ours, saturating towards
+ /// MRI_ModRef.
+ void addFunctionInfo(const FunctionInfo &FI) {
+ addModRefInfo(FI.getModRefInfo());
+
+ if (FI.mayReadAnyGlobal())
+ setMayReadAnyGlobal();
+
+ if (AlignedMap *P = FI.Info.getPointer())
+ for (const auto &G : P->Map)
+ addModRefInfoForGlobal(*G.first, G.second);
+ }
+
+ void addModRefInfoForGlobal(const GlobalValue &GV, ModRefInfo NewMRI) {
+ AlignedMap *P = Info.getPointer();
+ if (!P) {
+ P = new AlignedMap();
+ Info.setPointer(P);
+ }
+ auto &GlobalMRI = P->Map[&GV];
+ GlobalMRI = ModRefInfo(GlobalMRI | NewMRI);
+ }
+
+ /// Clear a global's ModRef info. Should be used when a global is being
+ /// deleted.
+ void eraseModRefInfoForGlobal(const GlobalValue &GV) {
+ if (AlignedMap *P = Info.getPointer())
+ P->Map.erase(&GV);
+ }
+
+private:
+ /// All of the information is encoded into a single pointer, with a three bit
+ /// integer in the low three bits. The high bit provides a flag for when this
+ /// function may read any global. The low two bits are the ModRefInfo. And
+ /// the pointer, when non-null, points to a map from GlobalValue to
+ /// ModRefInfo specific to that GlobalValue.
+ PointerIntPair<AlignedMap *, 3, unsigned, AlignedMapPointerTraits> Info;
+};
+
+void GlobalsModRef::DeletionCallbackHandle::deleted() {
+ Value *V = getValPtr();
+ if (auto *F = dyn_cast<Function>(V))
+ GMR.FunctionInfos.erase(F);
+
+ if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+ if (GMR.NonAddressTakenGlobals.erase(GV)) {
+ // This global might be an indirect global. If so, remove it and
+ // remove any AllocRelatedValues for it.
+ if (GMR.IndirectGlobals.erase(GV)) {
+ // Remove any entries in AllocsForIndirectGlobals for this global.
+ for (auto I = GMR.AllocsForIndirectGlobals.begin(),
+ E = GMR.AllocsForIndirectGlobals.end();
+ I != E; ++I)
+ if (I->second == GV)
+ GMR.AllocsForIndirectGlobals.erase(I);
+ }
+
+ // Scan the function info we have collected and remove this global
+ // from all of them.
+ for (auto &FIPair : GMR.FunctionInfos)
+ FIPair.second.eraseModRefInfoForGlobal(*GV);
+ }
+ }
+
+ // If this is an allocation related to an indirect global, remove it.
+ GMR.AllocsForIndirectGlobals.erase(V);
+
+ // And clear out the handle.
+ setValPtr(nullptr);
+ GMR.Handles.erase(I);
+ // This object is now destroyed!
+}
+
+char GlobalsModRef::ID = 0;
+INITIALIZE_AG_PASS_BEGIN(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
+ "Simple mod/ref analysis for globals", false, true,
+ false)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
+INITIALIZE_AG_PASS_END(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
+ "Simple mod/ref analysis for globals", false, true,
+ false)
+
+Pass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); }
+
+GlobalsModRef::GlobalsModRef() : ModulePass(ID) {
+ initializeGlobalsModRefPass(*PassRegistry::getPassRegistry());
+}
+
+FunctionModRefBehavior GlobalsModRef::getModRefBehavior(const Function *F) {
+ FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
+
+ if (FunctionInfo *FI = getFunctionInfo(F)) {
+ if (FI->getModRefInfo() == MRI_NoModRef)
+ Min = FMRB_DoesNotAccessMemory;
+ else if ((FI->getModRefInfo() & MRI_Mod) == 0)
+ Min = FMRB_OnlyReadsMemory;
+ }
+
+ return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
+}
+
+FunctionModRefBehavior GlobalsModRef::getModRefBehavior(ImmutableCallSite CS) {
+ FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
+
+ if (const Function *F = CS.getCalledFunction())
+ if (FunctionInfo *FI = getFunctionInfo(F)) {
+ if (FI->getModRefInfo() == MRI_NoModRef)
+ Min = FMRB_DoesNotAccessMemory;
+ else if ((FI->getModRefInfo() & MRI_Mod) == 0)
+ Min = FMRB_OnlyReadsMemory;
+ }
+
+ return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
+}
+
+/// Returns the function info for the function, or null if we don't have
+/// anything useful to say about it.
+GlobalsModRef::FunctionInfo *GlobalsModRef::getFunctionInfo(const Function *F) {
+ auto I = FunctionInfos.find(F);
+ if (I != FunctionInfos.end())
+ return &I->second;
+ return nullptr;
+}
+
+/// AnalyzeGlobals - Scan through the users of all of the internal
+/// GlobalValue's in the program. If none of them have their "address taken"
+/// (really, their address passed to something nontrivial), record this fact,
+/// and record the functions that they are used directly in.
+void GlobalsModRef::AnalyzeGlobals(Module &M) {
+ SmallPtrSet<Function *, 64> TrackedFunctions;
+ for (Function &F : M)
+ if (F.hasLocalLinkage())
+ if (!AnalyzeUsesOfPointer(&F)) {
+ // Remember that we are tracking this global.
+ NonAddressTakenGlobals.insert(&F);
+ TrackedFunctions.insert(&F);
+ Handles.emplace_front(*this, &F);
+ Handles.front().I = Handles.begin();
+ ++NumNonAddrTakenFunctions;
+ }
+
+ SmallPtrSet<Function *, 64> Readers, Writers;
+ for (GlobalVariable &GV : M.globals())
+ if (GV.hasLocalLinkage()) {
+ if (!AnalyzeUsesOfPointer(&GV, &Readers,
+ GV.isConstant() ? nullptr : &Writers)) {
+ // Remember that we are tracking this global, and the mod/ref fns
+ NonAddressTakenGlobals.insert(&GV);
+ Handles.emplace_front(*this, &GV);
+ Handles.front().I = Handles.begin();
+
+ for (Function *Reader : Readers) {
+ if (TrackedFunctions.insert(Reader).second) {
+ Handles.emplace_front(*this, Reader);
+ Handles.front().I = Handles.begin();
+ }
+ FunctionInfos[Reader].addModRefInfoForGlobal(GV, MRI_Ref);
+ }
+
+ if (!GV.isConstant()) // No need to keep track of writers to constants
+ for (Function *Writer : Writers) {
+ if (TrackedFunctions.insert(Writer).second) {
+ Handles.emplace_front(*this, Writer);
+ Handles.front().I = Handles.begin();
+ }
+ FunctionInfos[Writer].addModRefInfoForGlobal(GV, MRI_Mod);
+ }
+ ++NumNonAddrTakenGlobalVars;
+
+ // If this global holds a pointer type, see if it is an indirect global.
+ if (GV.getType()->getElementType()->isPointerTy() &&
+ AnalyzeIndirectGlobalMemory(&GV))
+ ++NumIndirectGlobalVars;
+ }
+ Readers.clear();
+ Writers.clear();
+ }
+}
+
+/// AnalyzeUsesOfPointer - Look at all of the users of the specified pointer.
+/// If this is used by anything complex (i.e., the address escapes), return
+/// true. Also, while we are at it, keep track of those functions that read and
+/// write to the value.
+///
+/// If OkayStoreDest is non-null, stores into this global are allowed.
+bool GlobalsModRef::AnalyzeUsesOfPointer(Value *V,
+ SmallPtrSetImpl<Function *> *Readers,
+ SmallPtrSetImpl<Function *> *Writers,
+ GlobalValue *OkayStoreDest) {
+ if (!V->getType()->isPointerTy())
+ return true;
+
+ for (Use &U : V->uses()) {
+ User *I = U.getUser();
+ if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
+ if (Readers)
+ Readers->insert(LI->getParent()->getParent());
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
+ if (V == SI->getOperand(1)) {
+ if (Writers)
+ Writers->insert(SI->getParent()->getParent());
+ } else if (SI->getOperand(1) != OkayStoreDest) {
+ return true; // Storing the pointer
+ }
+ } else if (Operator::getOpcode(I) == Instruction::GetElementPtr) {
+ if (AnalyzeUsesOfPointer(I, Readers, Writers))
+ return true;
+ } else if (Operator::getOpcode(I) == Instruction::BitCast) {
+ if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
+ return true;
+ } else if (auto CS = CallSite(I)) {
+ // Make sure that this is just the function being called, not that it is
+ // passing into the function.
+ if (!CS.isCallee(&U)) {
+ // Detect calls to free.
+ if (isFreeCall(I, TLI)) {
+ if (Writers)
+ Writers->insert(CS->getParent()->getParent());
+ } else {
+ return true; // Argument of an unknown call.
+ }
+ }
+ } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) {
+ if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
+ return true; // Allow comparison against null.
+ } else {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/// AnalyzeIndirectGlobalMemory - We found an non-address-taken global variable
+/// which holds a pointer type. See if the global always points to non-aliased
+/// heap memory: that is, all initializers of the globals are allocations, and
+/// those allocations have no use other than initialization of the global.
+/// Further, all loads out of GV must directly use the memory, not store the
+/// pointer somewhere. If this is true, we consider the memory pointed to by
+/// GV to be owned by GV and can disambiguate other pointers from it.
+bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
+ // Keep track of values related to the allocation of the memory, f.e. the
+ // value produced by the malloc call and any casts.
+ std::vector<Value *> AllocRelatedValues;
+
+ // Walk the user list of the global. If we find anything other than a direct
+ // load or store, bail out.
+ for (User *U : GV->users()) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
+ // The pointer loaded from the global can only be used in simple ways:
+ // we allow addressing of it and loading storing to it. We do *not* allow
+ // storing the loaded pointer somewhere else or passing to a function.
+ if (AnalyzeUsesOfPointer(LI))
+ return false; // Loaded pointer escapes.
+ // TODO: Could try some IP mod/ref of the loaded pointer.
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
+ // Storing the global itself.
+ if (SI->getOperand(0) == GV)
+ return false;
+
+ // If storing the null pointer, ignore it.
+ if (isa<ConstantPointerNull>(SI->getOperand(0)))
+ continue;
+
+ // Check the value being stored.
+ Value *Ptr = GetUnderlyingObject(SI->getOperand(0),
+ GV->getParent()->getDataLayout());
+
+ if (!isAllocLikeFn(Ptr, TLI))
+ return false; // Too hard to analyze.
+
+ // Analyze all uses of the allocation. If any of them are used in a
+ // non-simple way (e.g. stored to another global) bail out.
+ if (AnalyzeUsesOfPointer(Ptr, /*Readers*/ nullptr, /*Writers*/ nullptr,
+ GV))
+ return false; // Loaded pointer escapes.
+
+ // Remember that this allocation is related to the indirect global.
+ AllocRelatedValues.push_back(Ptr);
+ } else {
+ // Something complex, bail out.
+ return false;
+ }
+ }
+
+ // Okay, this is an indirect global. Remember all of the allocations for
+ // this global in AllocsForIndirectGlobals.
+ while (!AllocRelatedValues.empty()) {
+ AllocsForIndirectGlobals[AllocRelatedValues.back()] = GV;
+ Handles.emplace_front(*this, AllocRelatedValues.back());
+ Handles.front().I = Handles.begin();
+ AllocRelatedValues.pop_back();
+ }
+ IndirectGlobals.insert(GV);
+ Handles.emplace_front(*this, GV);
+ Handles.front().I = Handles.begin();
+ return true;
+}
+
+/// AnalyzeCallGraph - At this point, we know the functions where globals are
+/// immediately stored to and read from. Propagate this information up the call
+/// graph to all callers and compute the mod/ref info for all memory for each
+/// function.
+void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
+ // We do a bottom-up SCC traversal of the call graph. In other words, we
+ // visit all callees before callers (leaf-first).
+ for (scc_iterator<CallGraph *> I = scc_begin(&CG); !I.isAtEnd(); ++I) {
+ const std::vector<CallGraphNode *> &SCC = *I;
+ assert(!SCC.empty() && "SCC with no functions?");
+
+ if (!SCC[0]->getFunction()) {
+ // Calls externally - can't say anything useful. Remove any existing
+ // function records (may have been created when scanning globals).
+ for (auto *Node : SCC)
+ FunctionInfos.erase(Node->getFunction());
+ continue;
+ }
+
+ FunctionInfo &FI = FunctionInfos[SCC[0]->getFunction()];
+ bool KnowNothing = false;
+
+ // Collect the mod/ref properties due to called functions. We only compute
+ // one mod-ref set.
+ for (unsigned i = 0, e = SCC.size(); i != e && !KnowNothing; ++i) {
+ Function *F = SCC[i]->getFunction();
+ if (!F) {
+ KnowNothing = true;
+ break;
+ }
+
+ if (F->isDeclaration()) {
+ // Try to get mod/ref behaviour from function attributes.
+ if (F->doesNotAccessMemory()) {
+ // Can't do better than that!
+ } else if (F->onlyReadsMemory()) {
+ FI.addModRefInfo(MRI_Ref);
+ if (!F->isIntrinsic())
+ // This function might call back into the module and read a global -
+ // consider every global as possibly being read by this function.
+ FI.setMayReadAnyGlobal();
+ } else {
+ FI.addModRefInfo(MRI_ModRef);
+ // Can't say anything useful unless it's an intrinsic - they don't
+ // read or write global variables of the kind considered here.
+ KnowNothing = !F->isIntrinsic();
+ }
+ continue;
+ }
+
+ for (CallGraphNode::iterator CI = SCC[i]->begin(), E = SCC[i]->end();
+ CI != E && !KnowNothing; ++CI)
+ if (Function *Callee = CI->second->getFunction()) {
+ if (FunctionInfo *CalleeFI = getFunctionInfo(Callee)) {
+ // Propagate function effect up.
+ FI.addFunctionInfo(*CalleeFI);
+ } else {
+ // Can't say anything about it. However, if it is inside our SCC,
+ // then nothing needs to be done.
+ CallGraphNode *CalleeNode = CG[Callee];
+ if (std::find(SCC.begin(), SCC.end(), CalleeNode) == SCC.end())
+ KnowNothing = true;
+ }
+ } else {
+ KnowNothing = true;
+ }
+ }
+
+ // If we can't say anything useful about this SCC, remove all SCC functions
+ // from the FunctionInfos map.
+ if (KnowNothing) {
+ for (auto *Node : SCC)
+ FunctionInfos.erase(Node->getFunction());
+ continue;
+ }
+
+ // Scan the function bodies for explicit loads or stores.
+ for (auto *Node : SCC) {
+ if (FI.getModRefInfo() == MRI_ModRef)
+ break; // The mod/ref lattice saturates here.
+ for (Instruction &I : instructions(Node->getFunction())) {
+ if (FI.getModRefInfo() == MRI_ModRef)
+ break; // The mod/ref lattice saturates here.
+
+ // We handle calls specially because the graph-relevant aspects are
+ // handled above.
+ if (auto CS = CallSite(&I)) {
+ if (isAllocationFn(&I, TLI) || isFreeCall(&I, TLI)) {
+ // FIXME: It is completely unclear why this is necessary and not
+ // handled by the above graph code.
+ FI.addModRefInfo(MRI_ModRef);
+ } else if (Function *Callee = CS.getCalledFunction()) {
+ // The callgraph doesn't include intrinsic calls.
+ if (Callee->isIntrinsic()) {
+ FunctionModRefBehavior Behaviour =
+ AliasAnalysis::getModRefBehavior(Callee);
+ FI.addModRefInfo(ModRefInfo(Behaviour & MRI_ModRef));
+ }
+ }
+ continue;
+ }
+
+ // All non-call instructions we use the primary predicates for whether
+ // thay read or write memory.
+ if (I.mayReadFromMemory())
+ FI.addModRefInfo(MRI_Ref);
+ if (I.mayWriteToMemory())
+ FI.addModRefInfo(MRI_Mod);
+ }
+ }
+
+ if ((FI.getModRefInfo() & MRI_Mod) == 0)
+ ++NumReadMemFunctions;
+ if (FI.getModRefInfo() == MRI_NoModRef)
+ ++NumNoMemFunctions;
+
+ // Finally, now that we know the full effect on this SCC, clone the
+ // information to each function in the SCC.
+ for (unsigned i = 1, e = SCC.size(); i != e; ++i)
+ FunctionInfos[SCC[i]->getFunction()] = FI;
+ }
+}
+
+// There are particular cases where we can conclude no-alias between
+// a non-addr-taken global and some other underlying object. Specifically,
+// a non-addr-taken global is known to not be escaped from any function. It is
+// also incorrect for a transformation to introduce an escape of a global in
+// a way that is observable when it was not there previously. One function
+// being transformed to introduce an escape which could possibly be observed
+// (via loading from a global or the return value for example) within another
+// function is never safe. If the observation is made through non-atomic
+// operations on different threads, it is a data-race and UB. If the
+// observation is well defined, by being observed the transformation would have
+// changed program behavior by introducing the observed escape, making it an
+// invalid transform.
+//
+// This property does require that transformations which *temporarily* escape
+// a global that was not previously escaped, prior to restoring it, cannot rely
+// on the results of GMR::alias. This seems a reasonable restriction, although
+// currently there is no way to enforce it. There is also no realistic
+// optimization pass that would make this mistake. The closest example is
+// a transformation pass which does reg2mem of SSA values but stores them into
+// global variables temporarily before restoring the global variable's value.
+// This could be useful to expose "benign" races for example. However, it seems
+// reasonable to require that a pass which introduces escapes of global
+// variables in this way to either not trust AA results while the escape is
+// active, or to be forced to operate as a module pass that cannot co-exist
+// with an alias analysis such as GMR.
+bool GlobalsModRef::isNonEscapingGlobalNoAlias(const GlobalValue *GV,
+ const Value *V) {
+ // In order to know that the underlying object cannot alias the
+ // non-addr-taken global, we must know that it would have to be an escape.
+ // Thus if the underlying object is a function argument, a load from
+ // a global, or the return of a function, it cannot alias. We can also
+ // recurse through PHI nodes and select nodes provided all of their inputs
+ // resolve to one of these known-escaping roots.
+ SmallPtrSet<const Value *, 8> Visited;
+ SmallVector<const Value *, 8> Inputs;
+ Visited.insert(V);
+ Inputs.push_back(V);
+ int Depth = 0;
+ do {
+ const Value *Input = Inputs.pop_back_val();
+
+ if (auto *InputGV = dyn_cast<GlobalValue>(Input)) {
+ // If one input is the very global we're querying against, then we can't
+ // conclude no-alias.
+ if (InputGV == GV)
+ return false;
+
+ // Distinct GlobalVariables never alias, unless overriden or zero-sized.
+ // FIXME: The condition can be refined, but be conservative for now.
+ auto *GVar = dyn_cast<GlobalVariable>(GV);
+ auto *InputGVar = dyn_cast<GlobalVariable>(InputGV);
+ if (GVar && InputGVar &&
+ !GVar->isDeclaration() && !InputGVar->isDeclaration() &&
+ !GVar->mayBeOverridden() && !InputGVar->mayBeOverridden()) {
+ Type *GVType = GVar->getInitializer()->getType();
+ Type *InputGVType = InputGVar->getInitializer()->getType();
+ if (GVType->isSized() && InputGVType->isSized() &&
+ (DL->getTypeAllocSize(GVType) > 0) &&
+ (DL->getTypeAllocSize(InputGVType) > 0))
+ continue;
+ }
+
+ // Conservatively return false, even though we could be smarter
+ // (e.g. look through GlobalAliases).
+ return false;
+ }
+
+ if (isa<Argument>(Input) || isa<CallInst>(Input) ||
+ isa<InvokeInst>(Input)) {
+ // Arguments to functions or returns from functions are inherently
+ // escaping, so we can immediately classify those as not aliasing any
+ // non-addr-taken globals.
+ continue;
+ }
+ if (auto *LI = dyn_cast<LoadInst>(Input)) {
+ // A pointer loaded from a global would have been captured, and we know
+ // that the global is non-escaping, so no alias.
+ if (isa<GlobalValue>(GetUnderlyingObject(LI->getPointerOperand(), *DL)))
+ continue;
+
+ // Otherwise, a load could come from anywhere, so bail.
+ return false;
+ }
+
+ // Recurse through a limited number of selects and PHIs. This is an
+ // arbitrary depth of 4, lower numbers could be used to fix compile time
+ // issues if needed, but this is generally expected to be only be important
+ // for small depths.
+ if (++Depth > 4)
+ return false;
+ if (auto *SI = dyn_cast<SelectInst>(Input)) {
+ const Value *LHS = GetUnderlyingObject(SI->getTrueValue(), *DL);
+ const Value *RHS = GetUnderlyingObject(SI->getFalseValue(), *DL);
+ if (Visited.insert(LHS).second)
+ Inputs.push_back(LHS);
+ if (Visited.insert(RHS).second)
+ Inputs.push_back(RHS);
+ continue;
+ }
+ if (auto *PN = dyn_cast<PHINode>(Input)) {
+ for (const Value *Op : PN->incoming_values()) {
+ Op = GetUnderlyingObject(Op, *DL);
+ if (Visited.insert(Op).second)
+ Inputs.push_back(Op);
+ }
+ continue;
+ }
+
+ // FIXME: It would be good to handle other obvious no-alias cases here, but
+ // it isn't clear how to do so reasonbly without building a small version
+ // of BasicAA into this code. We could recurse into AliasAnalysis::alias
+ // here but that seems likely to go poorly as we're inside the
+ // implementation of such a query. Until then, just conservatievly retun
+ // false.
+ return false;
+ } while (!Inputs.empty());
+
+ // If all the inputs to V were definitively no-alias, then V is no-alias.
+ return true;
+}
+
+/// alias - If one of the pointers is to a global that we are tracking, and the
+/// other is some random pointer, we know there cannot be an alias, because the
+/// address of the global isn't taken.
+AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
+ const MemoryLocation &LocB) {
+ // Get the base object these pointers point to.
+ const Value *UV1 = GetUnderlyingObject(LocA.Ptr, *DL);
+ const Value *UV2 = GetUnderlyingObject(LocB.Ptr, *DL);
+
+ // If either of the underlying values is a global, they may be non-addr-taken
+ // globals, which we can answer queries about.
+ const GlobalValue *GV1 = dyn_cast<GlobalValue>(UV1);
+ const GlobalValue *GV2 = dyn_cast<GlobalValue>(UV2);
+ if (GV1 || GV2) {
+ // If the global's address is taken, pretend we don't know it's a pointer to
+ // the global.
+ if (GV1 && !NonAddressTakenGlobals.count(GV1))
+ GV1 = nullptr;
+ if (GV2 && !NonAddressTakenGlobals.count(GV2))
+ GV2 = nullptr;
+
+ // If the two pointers are derived from two different non-addr-taken
+ // globals we know these can't alias.
+ if (GV1 && GV2 && GV1 != GV2)
+ return NoAlias;
+
+ // If one is and the other isn't, it isn't strictly safe but we can fake
+ // this result if necessary for performance. This does not appear to be
+ // a common problem in practice.
+ if (EnableUnsafeGlobalsModRefAliasResults)
+ if ((GV1 || GV2) && GV1 != GV2)
+ return NoAlias;
+
+ // Check for a special case where a non-escaping global can be used to
+ // conclude no-alias.
+ if ((GV1 || GV2) && GV1 != GV2) {
+ const GlobalValue *GV = GV1 ? GV1 : GV2;
+ const Value *UV = GV1 ? UV2 : UV1;
+ if (isNonEscapingGlobalNoAlias(GV, UV))
+ return NoAlias;
+ }
+
+ // Otherwise if they are both derived from the same addr-taken global, we
+ // can't know the two accesses don't overlap.
+ }
+
+ // These pointers may be based on the memory owned by an indirect global. If
+ // so, we may be able to handle this. First check to see if the base pointer
+ // is a direct load from an indirect global.
+ GV1 = GV2 = nullptr;
+ if (const LoadInst *LI = dyn_cast<LoadInst>(UV1))
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
+ if (IndirectGlobals.count(GV))
+ GV1 = GV;
+ if (const LoadInst *LI = dyn_cast<LoadInst>(UV2))
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
+ if (IndirectGlobals.count(GV))
+ GV2 = GV;
+
+ // These pointers may also be from an allocation for the indirect global. If
+ // so, also handle them.
+ if (!GV1)
+ GV1 = AllocsForIndirectGlobals.lookup(UV1);
+ if (!GV2)
+ GV2 = AllocsForIndirectGlobals.lookup(UV2);
+
+ // Now that we know whether the two pointers are related to indirect globals,
+ // use this to disambiguate the pointers. If the pointers are based on
+ // different indirect globals they cannot alias.
+ if (GV1 && GV2 && GV1 != GV2)
+ return NoAlias;
+
+ // If one is based on an indirect global and the other isn't, it isn't
+ // strictly safe but we can fake this result if necessary for performance.
+ // This does not appear to be a common problem in practice.
+ if (EnableUnsafeGlobalsModRefAliasResults)
+ if ((GV1 || GV2) && GV1 != GV2)
+ return NoAlias;
+
+ return AliasAnalysis::alias(LocA, LocB);
+}
+
+ModRefInfo GlobalsModRef::getModRefInfo(ImmutableCallSite CS,
+ const MemoryLocation &Loc) {
+ unsigned Known = MRI_ModRef;
+
+ // If we are asking for mod/ref info of a direct call with a pointer to a
+ // global we are tracking, return information if we have it.
+ const DataLayout &DL = CS.getCaller()->getParent()->getDataLayout();
+ if (const GlobalValue *GV =
+ dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr, DL)))
+ if (GV->hasLocalLinkage())
+ if (const Function *F = CS.getCalledFunction())
+ if (NonAddressTakenGlobals.count(GV))
+ if (const FunctionInfo *FI = getFunctionInfo(F))
+ Known = FI->getModRefInfoForGlobal(*GV);
+
+ if (Known == MRI_NoModRef)
+ return MRI_NoModRef; // No need to query other mod/ref analyses
+ return ModRefInfo(Known & AliasAnalysis::getModRefInfo(CS, Loc));
+}
+++ /dev/null
-add_llvm_library(LLVMipa
- CallGraph.cpp
- CallGraphSCCPass.cpp
- CallPrinter.cpp
- GlobalsModRef.cpp
- IPA.cpp
- InlineCost.cpp
- )
-
-add_dependencies(LLVMipa intrinsics_gen)
+++ /dev/null
-//===- CallGraph.cpp - Build a Module's call graph ------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraph class methods.
-//
-
-CallGraph::CallGraph(Module &M)
- : M(M), Root(nullptr), ExternalCallingNode(getOrInsertFunction(nullptr)),
- CallsExternalNode(llvm::make_unique<CallGraphNode>(nullptr)) {
- // Add every function to the call graph.
- for (Function &F : M)
- addToCallGraph(&F);
-
- // If we didn't find a main function, use the external call graph node
- if (!Root)
- Root = ExternalCallingNode;
-}
-
-CallGraph::CallGraph(CallGraph &&Arg)
- : M(Arg.M), FunctionMap(std::move(Arg.FunctionMap)), Root(Arg.Root),
- ExternalCallingNode(Arg.ExternalCallingNode),
- CallsExternalNode(std::move(Arg.CallsExternalNode)) {
- Arg.FunctionMap.clear();
- Arg.Root = nullptr;
- Arg.ExternalCallingNode = nullptr;
-}
-
-CallGraph::~CallGraph() {
- // CallsExternalNode is not in the function map, delete it explicitly.
- if (CallsExternalNode)
- CallsExternalNode->allReferencesDropped();
-
-// Reset all node's use counts to zero before deleting them to prevent an
-// assertion from firing.
-#ifndef NDEBUG
- for (auto &I : FunctionMap)
- I.second->allReferencesDropped();
-#endif
-}
-
-void CallGraph::addToCallGraph(Function *F) {
- CallGraphNode *Node = getOrInsertFunction(F);
-
- // If this function has external linkage, anything could call it.
- if (!F->hasLocalLinkage()) {
- ExternalCallingNode->addCalledFunction(CallSite(), Node);
-
- // Found the entry point?
- if (F->getName() == "main") {
- if (Root) // Found multiple external mains? Don't pick one.
- Root = ExternalCallingNode;
- else
- Root = Node; // Found a main, keep track of it!
- }
- }
-
- // If this function has its address taken, anything could call it.
- if (F->hasAddressTaken())
- ExternalCallingNode->addCalledFunction(CallSite(), Node);
-
- // If this function is not defined in this translation unit, it could call
- // anything.
- if (F->isDeclaration() && !F->isIntrinsic())
- Node->addCalledFunction(CallSite(), CallsExternalNode.get());
-
- // Look for calls by this function.
- for (Function::iterator BB = F->begin(), BBE = F->end(); BB != BBE; ++BB)
- for (BasicBlock::iterator II = BB->begin(), IE = BB->end(); II != IE;
- ++II) {
- CallSite CS(cast<Value>(II));
- if (CS) {
- const Function *Callee = CS.getCalledFunction();
- if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
- // Indirect calls of intrinsics are not allowed so no need to check.
- // We can be more precise here by using TargetArg returned by
- // Intrinsic::isLeaf.
- Node->addCalledFunction(CS, CallsExternalNode.get());
- else if (!Callee->isIntrinsic())
- Node->addCalledFunction(CS, getOrInsertFunction(Callee));
- }
- }
-}
-
-void CallGraph::print(raw_ostream &OS) const {
- OS << "CallGraph Root is: ";
- if (Function *F = Root->getFunction())
- OS << F->getName() << "\n";
- else {
- OS << "<<null function: 0x" << Root << ">>\n";
- }
-
- // Print in a deterministic order by sorting CallGraphNodes by name. We do
- // this here to avoid slowing down the non-printing fast path.
-
- SmallVector<CallGraphNode *, 16> Nodes;
- Nodes.reserve(FunctionMap.size());
-
- for (auto I = begin(), E = end(); I != E; ++I)
- Nodes.push_back(I->second.get());
-
- std::sort(Nodes.begin(), Nodes.end(),
- [](CallGraphNode *LHS, CallGraphNode *RHS) {
- if (Function *LF = LHS->getFunction())
- if (Function *RF = RHS->getFunction())
- return LF->getName() < RF->getName();
-
- return RHS->getFunction() != nullptr;
- });
-
- for (CallGraphNode *CN : Nodes)
- CN->print(OS);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraph::dump() const { print(dbgs()); }
-#endif
-
-// removeFunctionFromModule - Unlink the function from this module, returning
-// it. Because this removes the function from the module, the call graph node
-// is destroyed. This is only valid if the function does not call any other
-// functions (ie, there are no edges in it's CGN). The easiest way to do this
-// is to dropAllReferences before calling this.
-//
-Function *CallGraph::removeFunctionFromModule(CallGraphNode *CGN) {
- assert(CGN->empty() && "Cannot remove function from call "
- "graph if it references other functions!");
- Function *F = CGN->getFunction(); // Get the function for the call graph node
- FunctionMap.erase(F); // Remove the call graph node from the map
-
- M.getFunctionList().remove(F);
- return F;
-}
-
-/// spliceFunction - Replace the function represented by this node by another.
-/// This does not rescan the body of the function, so it is suitable when
-/// splicing the body of the old function to the new while also updating all
-/// callers from old to new.
-///
-void CallGraph::spliceFunction(const Function *From, const Function *To) {
- assert(FunctionMap.count(From) && "No CallGraphNode for function!");
- assert(!FunctionMap.count(To) &&
- "Pointing CallGraphNode at a function that already exists");
- FunctionMapTy::iterator I = FunctionMap.find(From);
- I->second->F = const_cast<Function*>(To);
- FunctionMap[To] = std::move(I->second);
- FunctionMap.erase(I);
-}
-
-// getOrInsertFunction - This method is identical to calling operator[], but
-// it will insert a new CallGraphNode for the specified function if one does
-// not already exist.
-CallGraphNode *CallGraph::getOrInsertFunction(const Function *F) {
- auto &CGN = FunctionMap[F];
- if (CGN)
- return CGN.get();
-
- assert((!F || F->getParent() == &M) && "Function not in current module!");
- CGN = llvm::make_unique<CallGraphNode>(const_cast<Function *>(F));
- return CGN.get();
-}
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraphNode class methods.
-//
-
-void CallGraphNode::print(raw_ostream &OS) const {
- if (Function *F = getFunction())
- OS << "Call graph node for function: '" << F->getName() << "'";
- else
- OS << "Call graph node <<null function>>";
-
- OS << "<<" << this << ">> #uses=" << getNumReferences() << '\n';
-
- for (const_iterator I = begin(), E = end(); I != E; ++I) {
- OS << " CS<" << I->first << "> calls ";
- if (Function *FI = I->second->getFunction())
- OS << "function '" << FI->getName() <<"'\n";
- else
- OS << "external node\n";
- }
- OS << '\n';
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraphNode::dump() const { print(dbgs()); }
-#endif
-
-/// removeCallEdgeFor - This method removes the edge in the node for the
-/// specified call site. Note that this method takes linear time, so it
-/// should be used sparingly.
-void CallGraphNode::removeCallEdgeFor(CallSite CS) {
- for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
- assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
- if (I->first == CS.getInstruction()) {
- I->second->DropRef();
- *I = CalledFunctions.back();
- CalledFunctions.pop_back();
- return;
- }
- }
-}
-
-// removeAnyCallEdgeTo - This method removes any call edges from this node to
-// the specified callee function. This takes more time to execute than
-// removeCallEdgeTo, so it should not be used unless necessary.
-void CallGraphNode::removeAnyCallEdgeTo(CallGraphNode *Callee) {
- for (unsigned i = 0, e = CalledFunctions.size(); i != e; ++i)
- if (CalledFunctions[i].second == Callee) {
- Callee->DropRef();
- CalledFunctions[i] = CalledFunctions.back();
- CalledFunctions.pop_back();
- --i; --e;
- }
-}
-
-/// removeOneAbstractEdgeTo - Remove one edge associated with a null callsite
-/// from this node to the specified callee function.
-void CallGraphNode::removeOneAbstractEdgeTo(CallGraphNode *Callee) {
- for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
- assert(I != CalledFunctions.end() && "Cannot find callee to remove!");
- CallRecord &CR = *I;
- if (CR.second == Callee && CR.first == nullptr) {
- Callee->DropRef();
- *I = CalledFunctions.back();
- CalledFunctions.pop_back();
- return;
- }
- }
-}
-
-/// replaceCallEdge - This method replaces the edge in the node for the
-/// specified call site with a new one. Note that this method takes linear
-/// time, so it should be used sparingly.
-void CallGraphNode::replaceCallEdge(CallSite CS,
- CallSite NewCS, CallGraphNode *NewNode){
- for (CalledFunctionsVector::iterator I = CalledFunctions.begin(); ; ++I) {
- assert(I != CalledFunctions.end() && "Cannot find callsite to remove!");
- if (I->first == CS.getInstruction()) {
- I->second->DropRef();
- I->first = NewCS.getInstruction();
- I->second = NewNode;
- NewNode->AddRef();
- return;
- }
- }
-}
-
-//===----------------------------------------------------------------------===//
-// Out-of-line definitions of CallGraphAnalysis class members.
-//
-
-char CallGraphAnalysis::PassID;
-
-//===----------------------------------------------------------------------===//
-// Implementations of the CallGraphWrapperPass class methods.
-//
-
-CallGraphWrapperPass::CallGraphWrapperPass() : ModulePass(ID) {
- initializeCallGraphWrapperPassPass(*PassRegistry::getPassRegistry());
-}
-
-CallGraphWrapperPass::~CallGraphWrapperPass() {}
-
-void CallGraphWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
-}
-
-bool CallGraphWrapperPass::runOnModule(Module &M) {
- // All the real work is done in the constructor for the CallGraph.
- G.reset(new CallGraph(M));
- return false;
-}
-
-INITIALIZE_PASS(CallGraphWrapperPass, "basiccg", "CallGraph Construction",
- false, true)
-
-char CallGraphWrapperPass::ID = 0;
-
-void CallGraphWrapperPass::releaseMemory() { G.reset(); }
-
-void CallGraphWrapperPass::print(raw_ostream &OS, const Module *) const {
- if (!G) {
- OS << "No call graph has been built!\n";
- return;
- }
-
- // Just delegate.
- G->print(OS);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-void CallGraphWrapperPass::dump() const { print(dbgs(), nullptr); }
-#endif
+++ /dev/null
-//===- CallGraphSCCPass.cpp - Pass that operates BU on call graph ---------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the CallGraphSCCPass class, which is used for passes
-// which are implemented as bottom-up traversals on the call graph. Because
-// there may be cycles in the call graph, passes of this type operate on the
-// call-graph in SCC order: that is, they process function bottom-up, except for
-// recursive functions, which they process all at once.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraphSCCPass.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/LegacyPassManagers.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Timer.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "cgscc-passmgr"
-
-static cl::opt<unsigned>
-MaxIterations("max-cg-scc-iterations", cl::ReallyHidden, cl::init(4));
-
-STATISTIC(MaxSCCIterations, "Maximum CGSCCPassMgr iterations on one SCC");
-
-//===----------------------------------------------------------------------===//
-// CGPassManager
-//
-/// CGPassManager manages FPPassManagers and CallGraphSCCPasses.
-
-namespace {
-
-class CGPassManager : public ModulePass, public PMDataManager {
-public:
- static char ID;
- explicit CGPassManager()
- : ModulePass(ID), PMDataManager() { }
-
- /// Execute all of the passes scheduled for execution. Keep track of
- /// whether any of the passes modifies the module, and if so, return true.
- bool runOnModule(Module &M) override;
-
- using ModulePass::doInitialization;
- using ModulePass::doFinalization;
-
- bool doInitialization(CallGraph &CG);
- bool doFinalization(CallGraph &CG);
-
- /// Pass Manager itself does not invalidate any analysis info.
- void getAnalysisUsage(AnalysisUsage &Info) const override {
- // CGPassManager walks SCC and it needs CallGraph.
- Info.addRequired<CallGraphWrapperPass>();
- Info.setPreservesAll();
- }
-
- const char *getPassName() const override {
- return "CallGraph Pass Manager";
- }
-
- PMDataManager *getAsPMDataManager() override { return this; }
- Pass *getAsPass() override { return this; }
-
- // Print passes managed by this manager
- void dumpPassStructure(unsigned Offset) override {
- errs().indent(Offset*2) << "Call Graph SCC Pass Manager\n";
- for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
- Pass *P = getContainedPass(Index);
- P->dumpPassStructure(Offset + 1);
- dumpLastUses(P, Offset+1);
- }
- }
-
- Pass *getContainedPass(unsigned N) {
- assert(N < PassVector.size() && "Pass number out of range!");
- return static_cast<Pass *>(PassVector[N]);
- }
-
- PassManagerType getPassManagerType() const override {
- return PMT_CallGraphPassManager;
- }
-
-private:
- bool RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
- bool &DevirtualizedCall);
-
- bool RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
- CallGraph &CG, bool &CallGraphUpToDate,
- bool &DevirtualizedCall);
- bool RefreshCallGraph(CallGraphSCC &CurSCC, CallGraph &CG,
- bool IsCheckingMode);
-};
-
-} // end anonymous namespace.
-
-char CGPassManager::ID = 0;
-
-
-bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
- CallGraph &CG, bool &CallGraphUpToDate,
- bool &DevirtualizedCall) {
- bool Changed = false;
- PMDataManager *PM = P->getAsPMDataManager();
-
- if (!PM) {
- CallGraphSCCPass *CGSP = (CallGraphSCCPass*)P;
- if (!CallGraphUpToDate) {
- DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
- CallGraphUpToDate = true;
- }
-
- {
- TimeRegion PassTimer(getPassTimer(CGSP));
- Changed = CGSP->runOnSCC(CurSCC);
- }
-
- // After the CGSCCPass is done, when assertions are enabled, use
- // RefreshCallGraph to verify that the callgraph was correctly updated.
-#ifndef NDEBUG
- if (Changed)
- RefreshCallGraph(CurSCC, CG, true);
-#endif
-
- return Changed;
- }
-
-
- assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
- "Invalid CGPassManager member");
- FPPassManager *FPP = (FPPassManager*)P;
-
- // Run pass P on all functions in the current SCC.
- for (CallGraphNode *CGN : CurSCC) {
- if (Function *F = CGN->getFunction()) {
- dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
- {
- TimeRegion PassTimer(getPassTimer(FPP));
- Changed |= FPP->runOnFunction(*F);
- }
- F->getContext().yield();
- }
- }
-
- // The function pass(es) modified the IR, they may have clobbered the
- // callgraph.
- if (Changed && CallGraphUpToDate) {
- DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: "
- << P->getPassName() << '\n');
- CallGraphUpToDate = false;
- }
- return Changed;
-}
-
-
-/// Scan the functions in the specified CFG and resync the
-/// callgraph with the call sites found in it. This is used after
-/// FunctionPasses have potentially munged the callgraph, and can be used after
-/// CallGraphSCC passes to verify that they correctly updated the callgraph.
-///
-/// This function returns true if it devirtualized an existing function call,
-/// meaning it turned an indirect call into a direct call. This happens when
-/// a function pass like GVN optimizes away stuff feeding the indirect call.
-/// This never happens in checking mode.
-///
-bool CGPassManager::RefreshCallGraph(CallGraphSCC &CurSCC,
- CallGraph &CG, bool CheckingMode) {
- DenseMap<Value*, CallGraphNode*> CallSites;
-
- DEBUG(dbgs() << "CGSCCPASSMGR: Refreshing SCC with " << CurSCC.size()
- << " nodes:\n";
- for (CallGraphNode *CGN : CurSCC)
- CGN->dump();
- );
-
- bool MadeChange = false;
- bool DevirtualizedCall = false;
-
- // Scan all functions in the SCC.
- unsigned FunctionNo = 0;
- for (CallGraphSCC::iterator SCCIdx = CurSCC.begin(), E = CurSCC.end();
- SCCIdx != E; ++SCCIdx, ++FunctionNo) {
- CallGraphNode *CGN = *SCCIdx;
- Function *F = CGN->getFunction();
- if (!F || F->isDeclaration()) continue;
-
- // Walk the function body looking for call sites. Sync up the call sites in
- // CGN with those actually in the function.
-
- // Keep track of the number of direct and indirect calls that were
- // invalidated and removed.
- unsigned NumDirectRemoved = 0, NumIndirectRemoved = 0;
-
- // Get the set of call sites currently in the function.
- for (CallGraphNode::iterator I = CGN->begin(), E = CGN->end(); I != E; ) {
- // If this call site is null, then the function pass deleted the call
- // entirely and the WeakVH nulled it out.
- if (!I->first ||
- // If we've already seen this call site, then the FunctionPass RAUW'd
- // one call with another, which resulted in two "uses" in the edge
- // list of the same call.
- CallSites.count(I->first) ||
-
- // If the call edge is not from a call or invoke, or it is a
- // instrinsic call, then the function pass RAUW'd a call with
- // another value. This can happen when constant folding happens
- // of well known functions etc.
- !CallSite(I->first) ||
- (CallSite(I->first).getCalledFunction() &&
- CallSite(I->first).getCalledFunction()->isIntrinsic() &&
- Intrinsic::isLeaf(
- CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
- assert(!CheckingMode &&
- "CallGraphSCCPass did not update the CallGraph correctly!");
-
- // If this was an indirect call site, count it.
- if (!I->second->getFunction())
- ++NumIndirectRemoved;
- else
- ++NumDirectRemoved;
-
- // Just remove the edge from the set of callees, keep track of whether
- // I points to the last element of the vector.
- bool WasLast = I + 1 == E;
- CGN->removeCallEdge(I);
-
- // If I pointed to the last element of the vector, we have to bail out:
- // iterator checking rejects comparisons of the resultant pointer with
- // end.
- if (WasLast)
- break;
- E = CGN->end();
- continue;
- }
-
- assert(!CallSites.count(I->first) &&
- "Call site occurs in node multiple times");
-
- CallSite CS(I->first);
- if (CS) {
- Function *Callee = CS.getCalledFunction();
- // Ignore intrinsics because they're not really function calls.
- if (!Callee || !(Callee->isIntrinsic()))
- CallSites.insert(std::make_pair(I->first, I->second));
- }
- ++I;
- }
-
- // Loop over all of the instructions in the function, getting the callsites.
- // Keep track of the number of direct/indirect calls added.
- unsigned NumDirectAdded = 0, NumIndirectAdded = 0;
-
- for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
- CallSite CS(cast<Value>(I));
- if (!CS) continue;
- Function *Callee = CS.getCalledFunction();
- if (Callee && Callee->isIntrinsic()) continue;
-
- // If this call site already existed in the callgraph, just verify it
- // matches up to expectations and remove it from CallSites.
- DenseMap<Value*, CallGraphNode*>::iterator ExistingIt =
- CallSites.find(CS.getInstruction());
- if (ExistingIt != CallSites.end()) {
- CallGraphNode *ExistingNode = ExistingIt->second;
-
- // Remove from CallSites since we have now seen it.
- CallSites.erase(ExistingIt);
-
- // Verify that the callee is right.
- if (ExistingNode->getFunction() == CS.getCalledFunction())
- continue;
-
- // If we are in checking mode, we are not allowed to actually mutate
- // the callgraph. If this is a case where we can infer that the
- // callgraph is less precise than it could be (e.g. an indirect call
- // site could be turned direct), don't reject it in checking mode, and
- // don't tweak it to be more precise.
- if (CheckingMode && CS.getCalledFunction() &&
- ExistingNode->getFunction() == nullptr)
- continue;
-
- assert(!CheckingMode &&
- "CallGraphSCCPass did not update the CallGraph correctly!");
-
- // If not, we either went from a direct call to indirect, indirect to
- // direct, or direct to different direct.
- CallGraphNode *CalleeNode;
- if (Function *Callee = CS.getCalledFunction()) {
- CalleeNode = CG.getOrInsertFunction(Callee);
- // Keep track of whether we turned an indirect call into a direct
- // one.
- if (!ExistingNode->getFunction()) {
- DevirtualizedCall = true;
- DEBUG(dbgs() << " CGSCCPASSMGR: Devirtualized call to '"
- << Callee->getName() << "'\n");
- }
- } else {
- CalleeNode = CG.getCallsExternalNode();
- }
-
- // Update the edge target in CGN.
- CGN->replaceCallEdge(CS, CS, CalleeNode);
- MadeChange = true;
- continue;
- }
-
- assert(!CheckingMode &&
- "CallGraphSCCPass did not update the CallGraph correctly!");
-
- // If the call site didn't exist in the CGN yet, add it.
- CallGraphNode *CalleeNode;
- if (Function *Callee = CS.getCalledFunction()) {
- CalleeNode = CG.getOrInsertFunction(Callee);
- ++NumDirectAdded;
- } else {
- CalleeNode = CG.getCallsExternalNode();
- ++NumIndirectAdded;
- }
-
- CGN->addCalledFunction(CS, CalleeNode);
- MadeChange = true;
- }
-
- // We scanned the old callgraph node, removing invalidated call sites and
- // then added back newly found call sites. One thing that can happen is
- // that an old indirect call site was deleted and replaced with a new direct
- // call. In this case, we have devirtualized a call, and CGSCCPM would like
- // to iteratively optimize the new code. Unfortunately, we don't really
- // have a great way to detect when this happens. As an approximation, we
- // just look at whether the number of indirect calls is reduced and the
- // number of direct calls is increased. There are tons of ways to fool this
- // (e.g. DCE'ing an indirect call and duplicating an unrelated block with a
- // direct call) but this is close enough.
- if (NumIndirectRemoved > NumIndirectAdded &&
- NumDirectRemoved < NumDirectAdded)
- DevirtualizedCall = true;
-
- // After scanning this function, if we still have entries in callsites, then
- // they are dangling pointers. WeakVH should save us for this, so abort if
- // this happens.
- assert(CallSites.empty() && "Dangling pointers found in call sites map");
-
- // Periodically do an explicit clear to remove tombstones when processing
- // large scc's.
- if ((FunctionNo & 15) == 15)
- CallSites.clear();
- }
-
- DEBUG(if (MadeChange) {
- dbgs() << "CGSCCPASSMGR: Refreshed SCC is now:\n";
- for (CallGraphNode *CGN : CurSCC)
- CGN->dump();
- if (DevirtualizedCall)
- dbgs() << "CGSCCPASSMGR: Refresh devirtualized a call!\n";
-
- } else {
- dbgs() << "CGSCCPASSMGR: SCC Refresh didn't change call graph.\n";
- }
- );
- (void)MadeChange;
-
- return DevirtualizedCall;
-}
-
-/// Execute the body of the entire pass manager on the specified SCC.
-/// This keeps track of whether a function pass devirtualizes
-/// any calls and returns it in DevirtualizedCall.
-bool CGPassManager::RunAllPassesOnSCC(CallGraphSCC &CurSCC, CallGraph &CG,
- bool &DevirtualizedCall) {
- bool Changed = false;
-
- // Keep track of whether the callgraph is known to be up-to-date or not.
- // The CGSSC pass manager runs two types of passes:
- // CallGraphSCC Passes and other random function passes. Because other
- // random function passes are not CallGraph aware, they may clobber the
- // call graph by introducing new calls or deleting other ones. This flag
- // is set to false when we run a function pass so that we know to clean up
- // the callgraph when we need to run a CGSCCPass again.
- bool CallGraphUpToDate = true;
-
- // Run all passes on current SCC.
- for (unsigned PassNo = 0, e = getNumContainedPasses();
- PassNo != e; ++PassNo) {
- Pass *P = getContainedPass(PassNo);
-
- // If we're in -debug-pass=Executions mode, construct the SCC node list,
- // otherwise avoid constructing this string as it is expensive.
- if (isPassDebuggingExecutionsOrMore()) {
- std::string Functions;
- #ifndef NDEBUG
- raw_string_ostream OS(Functions);
- for (CallGraphSCC::iterator I = CurSCC.begin(), E = CurSCC.end();
- I != E; ++I) {
- if (I != CurSCC.begin()) OS << ", ";
- (*I)->print(OS);
- }
- OS.flush();
- #endif
- dumpPassInfo(P, EXECUTION_MSG, ON_CG_MSG, Functions);
- }
- dumpRequiredSet(P);
-
- initializeAnalysisImpl(P);
-
- // Actually run this pass on the current SCC.
- Changed |= RunPassOnSCC(P, CurSCC, CG,
- CallGraphUpToDate, DevirtualizedCall);
-
- if (Changed)
- dumpPassInfo(P, MODIFICATION_MSG, ON_CG_MSG, "");
- dumpPreservedSet(P);
-
- verifyPreservedAnalysis(P);
- removeNotPreservedAnalysis(P);
- recordAvailableAnalysis(P);
- removeDeadPasses(P, "", ON_CG_MSG);
- }
-
- // If the callgraph was left out of date (because the last pass run was a
- // functionpass), refresh it before we move on to the next SCC.
- if (!CallGraphUpToDate)
- DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
- return Changed;
-}
-
-/// Execute all of the passes scheduled for execution. Keep track of
-/// whether any of the passes modifies the module, and if so, return true.
-bool CGPassManager::runOnModule(Module &M) {
- CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
- bool Changed = doInitialization(CG);
-
- // Walk the callgraph in bottom-up SCC order.
- scc_iterator<CallGraph*> CGI = scc_begin(&CG);
-
- CallGraphSCC CurSCC(&CGI);
- while (!CGI.isAtEnd()) {
- // Copy the current SCC and increment past it so that the pass can hack
- // on the SCC if it wants to without invalidating our iterator.
- const std::vector<CallGraphNode *> &NodeVec = *CGI;
- CurSCC.initialize(NodeVec.data(), NodeVec.data() + NodeVec.size());
- ++CGI;
-
- // At the top level, we run all the passes in this pass manager on the
- // functions in this SCC. However, we support iterative compilation in the
- // case where a function pass devirtualizes a call to a function. For
- // example, it is very common for a function pass (often GVN or instcombine)
- // to eliminate the addressing that feeds into a call. With that improved
- // information, we would like the call to be an inline candidate, infer
- // mod-ref information etc.
- //
- // Because of this, we allow iteration up to a specified iteration count.
- // This only happens in the case of a devirtualized call, so we only burn
- // compile time in the case that we're making progress. We also have a hard
- // iteration count limit in case there is crazy code.
- unsigned Iteration = 0;
- bool DevirtualizedCall = false;
- do {
- DEBUG(if (Iteration)
- dbgs() << " SCCPASSMGR: Re-visiting SCC, iteration #"
- << Iteration << '\n');
- DevirtualizedCall = false;
- Changed |= RunAllPassesOnSCC(CurSCC, CG, DevirtualizedCall);
- } while (Iteration++ < MaxIterations && DevirtualizedCall);
-
- if (DevirtualizedCall)
- DEBUG(dbgs() << " CGSCCPASSMGR: Stopped iteration after " << Iteration
- << " times, due to -max-cg-scc-iterations\n");
-
- if (Iteration > MaxSCCIterations)
- MaxSCCIterations = Iteration;
-
- }
- Changed |= doFinalization(CG);
- return Changed;
-}
-
-
-/// Initialize CG
-bool CGPassManager::doInitialization(CallGraph &CG) {
- bool Changed = false;
- for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
- if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
- assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
- "Invalid CGPassManager member");
- Changed |= ((FPPassManager*)PM)->doInitialization(CG.getModule());
- } else {
- Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doInitialization(CG);
- }
- }
- return Changed;
-}
-
-/// Finalize CG
-bool CGPassManager::doFinalization(CallGraph &CG) {
- bool Changed = false;
- for (unsigned i = 0, e = getNumContainedPasses(); i != e; ++i) {
- if (PMDataManager *PM = getContainedPass(i)->getAsPMDataManager()) {
- assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
- "Invalid CGPassManager member");
- Changed |= ((FPPassManager*)PM)->doFinalization(CG.getModule());
- } else {
- Changed |= ((CallGraphSCCPass*)getContainedPass(i))->doFinalization(CG);
- }
- }
- return Changed;
-}
-
-//===----------------------------------------------------------------------===//
-// CallGraphSCC Implementation
-//===----------------------------------------------------------------------===//
-
-/// This informs the SCC and the pass manager that the specified
-/// Old node has been deleted, and New is to be used in its place.
-void CallGraphSCC::ReplaceNode(CallGraphNode *Old, CallGraphNode *New) {
- assert(Old != New && "Should not replace node with self");
- for (unsigned i = 0; ; ++i) {
- assert(i != Nodes.size() && "Node not in SCC");
- if (Nodes[i] != Old) continue;
- Nodes[i] = New;
- break;
- }
-
- // Update the active scc_iterator so that it doesn't contain dangling
- // pointers to the old CallGraphNode.
- scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
- CGI->ReplaceNode(Old, New);
-}
-
-
-//===----------------------------------------------------------------------===//
-// CallGraphSCCPass Implementation
-//===----------------------------------------------------------------------===//
-
-/// Assign pass manager to manage this pass.
-void CallGraphSCCPass::assignPassManager(PMStack &PMS,
- PassManagerType PreferredType) {
- // Find CGPassManager
- while (!PMS.empty() &&
- PMS.top()->getPassManagerType() > PMT_CallGraphPassManager)
- PMS.pop();
-
- assert(!PMS.empty() && "Unable to handle Call Graph Pass");
- CGPassManager *CGP;
-
- if (PMS.top()->getPassManagerType() == PMT_CallGraphPassManager)
- CGP = (CGPassManager*)PMS.top();
- else {
- // Create new Call Graph SCC Pass Manager if it does not exist.
- assert(!PMS.empty() && "Unable to create Call Graph Pass Manager");
- PMDataManager *PMD = PMS.top();
-
- // [1] Create new Call Graph Pass Manager
- CGP = new CGPassManager();
-
- // [2] Set up new manager's top level manager
- PMTopLevelManager *TPM = PMD->getTopLevelManager();
- TPM->addIndirectPassManager(CGP);
-
- // [3] Assign manager to manage this new manager. This may create
- // and push new managers into PMS
- Pass *P = CGP;
- TPM->schedulePass(P);
-
- // [4] Push new manager into PMS
- PMS.push(CGP);
- }
-
- CGP->add(this);
-}
-
-/// For this class, we declare that we require and preserve the call graph.
-/// If the derived class implements this method, it should
-/// always explicitly call the implementation here.
-void CallGraphSCCPass::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<CallGraphWrapperPass>();
- AU.addPreserved<CallGraphWrapperPass>();
-}
-
-
-//===----------------------------------------------------------------------===//
-// PrintCallGraphPass Implementation
-//===----------------------------------------------------------------------===//
-
-namespace {
- /// PrintCallGraphPass - Print a Module corresponding to a call graph.
- ///
- class PrintCallGraphPass : public CallGraphSCCPass {
- std::string Banner;
- raw_ostream &Out; // raw_ostream to print on.
-
- public:
- static char ID;
- PrintCallGraphPass(const std::string &B, raw_ostream &o)
- : CallGraphSCCPass(ID), Banner(B), Out(o) {}
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.setPreservesAll();
- }
-
- bool runOnSCC(CallGraphSCC &SCC) override {
- Out << Banner;
- for (CallGraphNode *CGN : SCC) {
- if (CGN->getFunction())
- CGN->getFunction()->print(Out);
- else
- Out << "\nPrinting <null> Function\n";
- }
- return false;
- }
- };
-
-} // end anonymous namespace.
-
-char PrintCallGraphPass::ID = 0;
-
-Pass *CallGraphSCCPass::createPrinterPass(raw_ostream &O,
- const std::string &Banner) const {
- return new PrintCallGraphPass(Banner, O);
-}
-
+++ /dev/null
-//===- CallPrinter.cpp - DOT printer for call graph -----------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines '-dot-callgraph', which emit a callgraph.<fnname>.dot
-// containing the call graph of a module.
-//
-// There is also a pass available to directly call dotty ('-view-callgraph').
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/Analysis/CallPrinter.h"
-#include "llvm/Analysis/DOTGraphTraitsPass.h"
-
-using namespace llvm;
-
-namespace llvm {
-
-template <> struct DOTGraphTraits<CallGraph *> : public DefaultDOTGraphTraits {
- DOTGraphTraits(bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
-
- static std::string getGraphName(CallGraph *Graph) { return "Call graph"; }
-
- std::string getNodeLabel(CallGraphNode *Node, CallGraph *Graph) {
- if (Function *Func = Node->getFunction())
- return Func->getName();
-
- return "external node";
- }
-};
-
-struct AnalysisCallGraphWrapperPassTraits {
- static CallGraph *getGraph(CallGraphWrapperPass *P) {
- return &P->getCallGraph();
- }
-};
-
-} // end llvm namespace
-
-namespace {
-
-struct CallGraphViewer
- : public DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
- AnalysisCallGraphWrapperPassTraits> {
- static char ID;
-
- CallGraphViewer()
- : DOTGraphTraitsModuleViewer<CallGraphWrapperPass, true, CallGraph *,
- AnalysisCallGraphWrapperPassTraits>(
- "callgraph", ID) {
- initializeCallGraphViewerPass(*PassRegistry::getPassRegistry());
- }
-};
-
-struct CallGraphPrinter : public DOTGraphTraitsModulePrinter<
- CallGraphWrapperPass, true, CallGraph *,
- AnalysisCallGraphWrapperPassTraits> {
- static char ID;
-
- CallGraphPrinter()
- : DOTGraphTraitsModulePrinter<CallGraphWrapperPass, true, CallGraph *,
- AnalysisCallGraphWrapperPassTraits>(
- "callgraph", ID) {
- initializeCallGraphPrinterPass(*PassRegistry::getPassRegistry());
- }
-};
-
-} // end anonymous namespace
-
-char CallGraphViewer::ID = 0;
-INITIALIZE_PASS(CallGraphViewer, "view-callgraph", "View call graph", false,
- false)
-
-char CallGraphPrinter::ID = 0;
-INITIALIZE_PASS(CallGraphPrinter, "dot-callgraph",
- "Print call graph to 'dot' file", false, false)
-
-// Create methods available outside of this file, to use them
-// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
-// the link time optimization.
-
-ModulePass *llvm::createCallGraphViewerPass() { return new CallGraphViewer(); }
-
-ModulePass *llvm::createCallGraphPrinterPass() {
- return new CallGraphPrinter();
-}
+++ /dev/null
-//===- GlobalsModRef.cpp - Simple Mod/Ref Analysis for Globals ------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This simple pass provides alias and mod/ref information for global values
-// that do not have their address taken, and keeps track of whether functions
-// read or write memory (are "pure"). For this simple (but very common) case,
-// we can provide pretty accurate and useful information.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/GlobalsModRef.h"
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/MemoryBuiltins.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/CommandLine.h"
-using namespace llvm;
-
-#define DEBUG_TYPE "globalsmodref-aa"
-
-STATISTIC(NumNonAddrTakenGlobalVars,
- "Number of global vars without address taken");
-STATISTIC(NumNonAddrTakenFunctions,"Number of functions without address taken");
-STATISTIC(NumNoMemFunctions, "Number of functions that do not access memory");
-STATISTIC(NumReadMemFunctions, "Number of functions that only read memory");
-STATISTIC(NumIndirectGlobalVars, "Number of indirect global objects");
-
-// An option to enable unsafe alias results from the GlobalsModRef analysis.
-// When enabled, GlobalsModRef will provide no-alias results which in extremely
-// rare cases may not be conservatively correct. In particular, in the face of
-// transforms which cause assymetry between how effective GetUnderlyingObject
-// is for two pointers, it may produce incorrect results.
-//
-// These unsafe results have been returned by GMR for many years without
-// causing significant issues in the wild and so we provide a mechanism to
-// re-enable them for users of LLVM that have a particular performance
-// sensitivity and no known issues. The option also makes it easy to evaluate
-// the performance impact of these results.
-static cl::opt<bool> EnableUnsafeGlobalsModRefAliasResults(
- "enable-unsafe-globalsmodref-alias-results", cl::init(false), cl::Hidden);
-
-/// The mod/ref information collected for a particular function.
-///
-/// We collect information about mod/ref behavior of a function here, both in
-/// general and as pertains to specific globals. We only have this detailed
-/// information when we know *something* useful about the behavior. If we
-/// saturate to fully general mod/ref, we remove the info for the function.
-class GlobalsModRef::FunctionInfo {
- typedef SmallDenseMap<const GlobalValue *, ModRefInfo, 16> GlobalInfoMapType;
-
- /// Build a wrapper struct that has 8-byte alignment. All heap allocations
- /// should provide this much alignment at least, but this makes it clear we
- /// specifically rely on this amount of alignment.
- struct LLVM_ALIGNAS(8) AlignedMap {
- AlignedMap() {}
- AlignedMap(const AlignedMap &Arg) : Map(Arg.Map) {}
- GlobalInfoMapType Map;
- };
-
- /// Pointer traits for our aligned map.
- struct AlignedMapPointerTraits {
- static inline void *getAsVoidPointer(AlignedMap *P) { return P; }
- static inline AlignedMap *getFromVoidPointer(void *P) {
- return (AlignedMap *)P;
- }
- enum { NumLowBitsAvailable = 3 };
- static_assert(AlignOf<AlignedMap>::Alignment >= (1 << NumLowBitsAvailable),
- "AlignedMap insufficiently aligned to have enough low bits.");
- };
-
- /// The bit that flags that this function may read any global. This is
- /// chosen to mix together with ModRefInfo bits.
- enum { MayReadAnyGlobal = 4 };
-
- /// Checks to document the invariants of the bit packing here.
- static_assert((MayReadAnyGlobal & MRI_ModRef) == 0,
- "ModRef and the MayReadAnyGlobal flag bits overlap.");
- static_assert(((MayReadAnyGlobal | MRI_ModRef) >>
- AlignedMapPointerTraits::NumLowBitsAvailable) == 0,
- "Insufficient low bits to store our flag and ModRef info.");
-
-public:
- FunctionInfo() : Info() {}
- ~FunctionInfo() {
- delete Info.getPointer();
- }
- // Spell out the copy ond move constructors and assignment operators to get
- // deep copy semantics and correct move semantics in the face of the
- // pointer-int pair.
- FunctionInfo(const FunctionInfo &Arg)
- : Info(nullptr, Arg.Info.getInt()) {
- if (const auto *ArgPtr = Arg.Info.getPointer())
- Info.setPointer(new AlignedMap(*ArgPtr));
- }
- FunctionInfo(FunctionInfo &&Arg)
- : Info(Arg.Info.getPointer(), Arg.Info.getInt()) {
- Arg.Info.setPointerAndInt(nullptr, 0);
- }
- FunctionInfo &operator=(const FunctionInfo &RHS) {
- delete Info.getPointer();
- Info.setPointerAndInt(nullptr, RHS.Info.getInt());
- if (const auto *RHSPtr = RHS.Info.getPointer())
- Info.setPointer(new AlignedMap(*RHSPtr));
- return *this;
- }
- FunctionInfo &operator=(FunctionInfo &&RHS) {
- delete Info.getPointer();
- Info.setPointerAndInt(RHS.Info.getPointer(), RHS.Info.getInt());
- RHS.Info.setPointerAndInt(nullptr, 0);
- return *this;
- }
-
- /// Returns the \c ModRefInfo info for this function.
- ModRefInfo getModRefInfo() const {
- return ModRefInfo(Info.getInt() & MRI_ModRef);
- }
-
- /// Adds new \c ModRefInfo for this function to its state.
- void addModRefInfo(ModRefInfo NewMRI) {
- Info.setInt(Info.getInt() | NewMRI);
- }
-
- /// Returns whether this function may read any global variable, and we don't
- /// know which global.
- bool mayReadAnyGlobal() const { return Info.getInt() & MayReadAnyGlobal; }
-
- /// Sets this function as potentially reading from any global.
- void setMayReadAnyGlobal() { Info.setInt(Info.getInt() | MayReadAnyGlobal); }
-
- /// Returns the \c ModRefInfo info for this function w.r.t. a particular
- /// global, which may be more precise than the general information above.
- ModRefInfo getModRefInfoForGlobal(const GlobalValue &GV) const {
- ModRefInfo GlobalMRI = mayReadAnyGlobal() ? MRI_Ref : MRI_NoModRef;
- if (AlignedMap *P = Info.getPointer()) {
- auto I = P->Map.find(&GV);
- if (I != P->Map.end())
- GlobalMRI = ModRefInfo(GlobalMRI | I->second);
- }
- return GlobalMRI;
- }
-
- /// Add mod/ref info from another function into ours, saturating towards
- /// MRI_ModRef.
- void addFunctionInfo(const FunctionInfo &FI) {
- addModRefInfo(FI.getModRefInfo());
-
- if (FI.mayReadAnyGlobal())
- setMayReadAnyGlobal();
-
- if (AlignedMap *P = FI.Info.getPointer())
- for (const auto &G : P->Map)
- addModRefInfoForGlobal(*G.first, G.second);
- }
-
- void addModRefInfoForGlobal(const GlobalValue &GV, ModRefInfo NewMRI) {
- AlignedMap *P = Info.getPointer();
- if (!P) {
- P = new AlignedMap();
- Info.setPointer(P);
- }
- auto &GlobalMRI = P->Map[&GV];
- GlobalMRI = ModRefInfo(GlobalMRI | NewMRI);
- }
-
- /// Clear a global's ModRef info. Should be used when a global is being
- /// deleted.
- void eraseModRefInfoForGlobal(const GlobalValue &GV) {
- if (AlignedMap *P = Info.getPointer())
- P->Map.erase(&GV);
- }
-
-private:
- /// All of the information is encoded into a single pointer, with a three bit
- /// integer in the low three bits. The high bit provides a flag for when this
- /// function may read any global. The low two bits are the ModRefInfo. And
- /// the pointer, when non-null, points to a map from GlobalValue to
- /// ModRefInfo specific to that GlobalValue.
- PointerIntPair<AlignedMap *, 3, unsigned, AlignedMapPointerTraits> Info;
-};
-
-void GlobalsModRef::DeletionCallbackHandle::deleted() {
- Value *V = getValPtr();
- if (auto *F = dyn_cast<Function>(V))
- GMR.FunctionInfos.erase(F);
-
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- if (GMR.NonAddressTakenGlobals.erase(GV)) {
- // This global might be an indirect global. If so, remove it and
- // remove any AllocRelatedValues for it.
- if (GMR.IndirectGlobals.erase(GV)) {
- // Remove any entries in AllocsForIndirectGlobals for this global.
- for (auto I = GMR.AllocsForIndirectGlobals.begin(),
- E = GMR.AllocsForIndirectGlobals.end();
- I != E; ++I)
- if (I->second == GV)
- GMR.AllocsForIndirectGlobals.erase(I);
- }
-
- // Scan the function info we have collected and remove this global
- // from all of them.
- for (auto &FIPair : GMR.FunctionInfos)
- FIPair.second.eraseModRefInfoForGlobal(*GV);
- }
- }
-
- // If this is an allocation related to an indirect global, remove it.
- GMR.AllocsForIndirectGlobals.erase(V);
-
- // And clear out the handle.
- setValPtr(nullptr);
- GMR.Handles.erase(I);
- // This object is now destroyed!
-}
-
-char GlobalsModRef::ID = 0;
-INITIALIZE_AG_PASS_BEGIN(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
- "Simple mod/ref analysis for globals", false, true,
- false)
-INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
-INITIALIZE_AG_PASS_END(GlobalsModRef, AliasAnalysis, "globalsmodref-aa",
- "Simple mod/ref analysis for globals", false, true,
- false)
-
-Pass *llvm::createGlobalsModRefPass() { return new GlobalsModRef(); }
-
-GlobalsModRef::GlobalsModRef() : ModulePass(ID) {
- initializeGlobalsModRefPass(*PassRegistry::getPassRegistry());
-}
-
-FunctionModRefBehavior GlobalsModRef::getModRefBehavior(const Function *F) {
- FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
-
- if (FunctionInfo *FI = getFunctionInfo(F)) {
- if (FI->getModRefInfo() == MRI_NoModRef)
- Min = FMRB_DoesNotAccessMemory;
- else if ((FI->getModRefInfo() & MRI_Mod) == 0)
- Min = FMRB_OnlyReadsMemory;
- }
-
- return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(F) & Min);
-}
-
-FunctionModRefBehavior GlobalsModRef::getModRefBehavior(ImmutableCallSite CS) {
- FunctionModRefBehavior Min = FMRB_UnknownModRefBehavior;
-
- if (const Function *F = CS.getCalledFunction())
- if (FunctionInfo *FI = getFunctionInfo(F)) {
- if (FI->getModRefInfo() == MRI_NoModRef)
- Min = FMRB_DoesNotAccessMemory;
- else if ((FI->getModRefInfo() & MRI_Mod) == 0)
- Min = FMRB_OnlyReadsMemory;
- }
-
- return FunctionModRefBehavior(AliasAnalysis::getModRefBehavior(CS) & Min);
-}
-
-/// Returns the function info for the function, or null if we don't have
-/// anything useful to say about it.
-GlobalsModRef::FunctionInfo *GlobalsModRef::getFunctionInfo(const Function *F) {
- auto I = FunctionInfos.find(F);
- if (I != FunctionInfos.end())
- return &I->second;
- return nullptr;
-}
-
-/// AnalyzeGlobals - Scan through the users of all of the internal
-/// GlobalValue's in the program. If none of them have their "address taken"
-/// (really, their address passed to something nontrivial), record this fact,
-/// and record the functions that they are used directly in.
-void GlobalsModRef::AnalyzeGlobals(Module &M) {
- SmallPtrSet<Function *, 64> TrackedFunctions;
- for (Function &F : M)
- if (F.hasLocalLinkage())
- if (!AnalyzeUsesOfPointer(&F)) {
- // Remember that we are tracking this global.
- NonAddressTakenGlobals.insert(&F);
- TrackedFunctions.insert(&F);
- Handles.emplace_front(*this, &F);
- Handles.front().I = Handles.begin();
- ++NumNonAddrTakenFunctions;
- }
-
- SmallPtrSet<Function *, 64> Readers, Writers;
- for (GlobalVariable &GV : M.globals())
- if (GV.hasLocalLinkage()) {
- if (!AnalyzeUsesOfPointer(&GV, &Readers,
- GV.isConstant() ? nullptr : &Writers)) {
- // Remember that we are tracking this global, and the mod/ref fns
- NonAddressTakenGlobals.insert(&GV);
- Handles.emplace_front(*this, &GV);
- Handles.front().I = Handles.begin();
-
- for (Function *Reader : Readers) {
- if (TrackedFunctions.insert(Reader).second) {
- Handles.emplace_front(*this, Reader);
- Handles.front().I = Handles.begin();
- }
- FunctionInfos[Reader].addModRefInfoForGlobal(GV, MRI_Ref);
- }
-
- if (!GV.isConstant()) // No need to keep track of writers to constants
- for (Function *Writer : Writers) {
- if (TrackedFunctions.insert(Writer).second) {
- Handles.emplace_front(*this, Writer);
- Handles.front().I = Handles.begin();
- }
- FunctionInfos[Writer].addModRefInfoForGlobal(GV, MRI_Mod);
- }
- ++NumNonAddrTakenGlobalVars;
-
- // If this global holds a pointer type, see if it is an indirect global.
- if (GV.getType()->getElementType()->isPointerTy() &&
- AnalyzeIndirectGlobalMemory(&GV))
- ++NumIndirectGlobalVars;
- }
- Readers.clear();
- Writers.clear();
- }
-}
-
-/// AnalyzeUsesOfPointer - Look at all of the users of the specified pointer.
-/// If this is used by anything complex (i.e., the address escapes), return
-/// true. Also, while we are at it, keep track of those functions that read and
-/// write to the value.
-///
-/// If OkayStoreDest is non-null, stores into this global are allowed.
-bool GlobalsModRef::AnalyzeUsesOfPointer(Value *V,
- SmallPtrSetImpl<Function *> *Readers,
- SmallPtrSetImpl<Function *> *Writers,
- GlobalValue *OkayStoreDest) {
- if (!V->getType()->isPointerTy())
- return true;
-
- for (Use &U : V->uses()) {
- User *I = U.getUser();
- if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
- if (Readers)
- Readers->insert(LI->getParent()->getParent());
- } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
- if (V == SI->getOperand(1)) {
- if (Writers)
- Writers->insert(SI->getParent()->getParent());
- } else if (SI->getOperand(1) != OkayStoreDest) {
- return true; // Storing the pointer
- }
- } else if (Operator::getOpcode(I) == Instruction::GetElementPtr) {
- if (AnalyzeUsesOfPointer(I, Readers, Writers))
- return true;
- } else if (Operator::getOpcode(I) == Instruction::BitCast) {
- if (AnalyzeUsesOfPointer(I, Readers, Writers, OkayStoreDest))
- return true;
- } else if (auto CS = CallSite(I)) {
- // Make sure that this is just the function being called, not that it is
- // passing into the function.
- if (!CS.isCallee(&U)) {
- // Detect calls to free.
- if (isFreeCall(I, TLI)) {
- if (Writers)
- Writers->insert(CS->getParent()->getParent());
- } else {
- return true; // Argument of an unknown call.
- }
- }
- } else if (ICmpInst *ICI = dyn_cast<ICmpInst>(I)) {
- if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
- return true; // Allow comparison against null.
- } else {
- return true;
- }
- }
-
- return false;
-}
-
-/// AnalyzeIndirectGlobalMemory - We found an non-address-taken global variable
-/// which holds a pointer type. See if the global always points to non-aliased
-/// heap memory: that is, all initializers of the globals are allocations, and
-/// those allocations have no use other than initialization of the global.
-/// Further, all loads out of GV must directly use the memory, not store the
-/// pointer somewhere. If this is true, we consider the memory pointed to by
-/// GV to be owned by GV and can disambiguate other pointers from it.
-bool GlobalsModRef::AnalyzeIndirectGlobalMemory(GlobalValue *GV) {
- // Keep track of values related to the allocation of the memory, f.e. the
- // value produced by the malloc call and any casts.
- std::vector<Value *> AllocRelatedValues;
-
- // Walk the user list of the global. If we find anything other than a direct
- // load or store, bail out.
- for (User *U : GV->users()) {
- if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
- // The pointer loaded from the global can only be used in simple ways:
- // we allow addressing of it and loading storing to it. We do *not* allow
- // storing the loaded pointer somewhere else or passing to a function.
- if (AnalyzeUsesOfPointer(LI))
- return false; // Loaded pointer escapes.
- // TODO: Could try some IP mod/ref of the loaded pointer.
- } else if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
- // Storing the global itself.
- if (SI->getOperand(0) == GV)
- return false;
-
- // If storing the null pointer, ignore it.
- if (isa<ConstantPointerNull>(SI->getOperand(0)))
- continue;
-
- // Check the value being stored.
- Value *Ptr = GetUnderlyingObject(SI->getOperand(0),
- GV->getParent()->getDataLayout());
-
- if (!isAllocLikeFn(Ptr, TLI))
- return false; // Too hard to analyze.
-
- // Analyze all uses of the allocation. If any of them are used in a
- // non-simple way (e.g. stored to another global) bail out.
- if (AnalyzeUsesOfPointer(Ptr, /*Readers*/ nullptr, /*Writers*/ nullptr,
- GV))
- return false; // Loaded pointer escapes.
-
- // Remember that this allocation is related to the indirect global.
- AllocRelatedValues.push_back(Ptr);
- } else {
- // Something complex, bail out.
- return false;
- }
- }
-
- // Okay, this is an indirect global. Remember all of the allocations for
- // this global in AllocsForIndirectGlobals.
- while (!AllocRelatedValues.empty()) {
- AllocsForIndirectGlobals[AllocRelatedValues.back()] = GV;
- Handles.emplace_front(*this, AllocRelatedValues.back());
- Handles.front().I = Handles.begin();
- AllocRelatedValues.pop_back();
- }
- IndirectGlobals.insert(GV);
- Handles.emplace_front(*this, GV);
- Handles.front().I = Handles.begin();
- return true;
-}
-
-/// AnalyzeCallGraph - At this point, we know the functions where globals are
-/// immediately stored to and read from. Propagate this information up the call
-/// graph to all callers and compute the mod/ref info for all memory for each
-/// function.
-void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
- // We do a bottom-up SCC traversal of the call graph. In other words, we
- // visit all callees before callers (leaf-first).
- for (scc_iterator<CallGraph *> I = scc_begin(&CG); !I.isAtEnd(); ++I) {
- const std::vector<CallGraphNode *> &SCC = *I;
- assert(!SCC.empty() && "SCC with no functions?");
-
- if (!SCC[0]->getFunction()) {
- // Calls externally - can't say anything useful. Remove any existing
- // function records (may have been created when scanning globals).
- for (auto *Node : SCC)
- FunctionInfos.erase(Node->getFunction());
- continue;
- }
-
- FunctionInfo &FI = FunctionInfos[SCC[0]->getFunction()];
- bool KnowNothing = false;
-
- // Collect the mod/ref properties due to called functions. We only compute
- // one mod-ref set.
- for (unsigned i = 0, e = SCC.size(); i != e && !KnowNothing; ++i) {
- Function *F = SCC[i]->getFunction();
- if (!F) {
- KnowNothing = true;
- break;
- }
-
- if (F->isDeclaration()) {
- // Try to get mod/ref behaviour from function attributes.
- if (F->doesNotAccessMemory()) {
- // Can't do better than that!
- } else if (F->onlyReadsMemory()) {
- FI.addModRefInfo(MRI_Ref);
- if (!F->isIntrinsic())
- // This function might call back into the module and read a global -
- // consider every global as possibly being read by this function.
- FI.setMayReadAnyGlobal();
- } else {
- FI.addModRefInfo(MRI_ModRef);
- // Can't say anything useful unless it's an intrinsic - they don't
- // read or write global variables of the kind considered here.
- KnowNothing = !F->isIntrinsic();
- }
- continue;
- }
-
- for (CallGraphNode::iterator CI = SCC[i]->begin(), E = SCC[i]->end();
- CI != E && !KnowNothing; ++CI)
- if (Function *Callee = CI->second->getFunction()) {
- if (FunctionInfo *CalleeFI = getFunctionInfo(Callee)) {
- // Propagate function effect up.
- FI.addFunctionInfo(*CalleeFI);
- } else {
- // Can't say anything about it. However, if it is inside our SCC,
- // then nothing needs to be done.
- CallGraphNode *CalleeNode = CG[Callee];
- if (std::find(SCC.begin(), SCC.end(), CalleeNode) == SCC.end())
- KnowNothing = true;
- }
- } else {
- KnowNothing = true;
- }
- }
-
- // If we can't say anything useful about this SCC, remove all SCC functions
- // from the FunctionInfos map.
- if (KnowNothing) {
- for (auto *Node : SCC)
- FunctionInfos.erase(Node->getFunction());
- continue;
- }
-
- // Scan the function bodies for explicit loads or stores.
- for (auto *Node : SCC) {
- if (FI.getModRefInfo() == MRI_ModRef)
- break; // The mod/ref lattice saturates here.
- for (Instruction &I : instructions(Node->getFunction())) {
- if (FI.getModRefInfo() == MRI_ModRef)
- break; // The mod/ref lattice saturates here.
-
- // We handle calls specially because the graph-relevant aspects are
- // handled above.
- if (auto CS = CallSite(&I)) {
- if (isAllocationFn(&I, TLI) || isFreeCall(&I, TLI)) {
- // FIXME: It is completely unclear why this is necessary and not
- // handled by the above graph code.
- FI.addModRefInfo(MRI_ModRef);
- } else if (Function *Callee = CS.getCalledFunction()) {
- // The callgraph doesn't include intrinsic calls.
- if (Callee->isIntrinsic()) {
- FunctionModRefBehavior Behaviour =
- AliasAnalysis::getModRefBehavior(Callee);
- FI.addModRefInfo(ModRefInfo(Behaviour & MRI_ModRef));
- }
- }
- continue;
- }
-
- // All non-call instructions we use the primary predicates for whether
- // thay read or write memory.
- if (I.mayReadFromMemory())
- FI.addModRefInfo(MRI_Ref);
- if (I.mayWriteToMemory())
- FI.addModRefInfo(MRI_Mod);
- }
- }
-
- if ((FI.getModRefInfo() & MRI_Mod) == 0)
- ++NumReadMemFunctions;
- if (FI.getModRefInfo() == MRI_NoModRef)
- ++NumNoMemFunctions;
-
- // Finally, now that we know the full effect on this SCC, clone the
- // information to each function in the SCC.
- for (unsigned i = 1, e = SCC.size(); i != e; ++i)
- FunctionInfos[SCC[i]->getFunction()] = FI;
- }
-}
-
-// There are particular cases where we can conclude no-alias between
-// a non-addr-taken global and some other underlying object. Specifically,
-// a non-addr-taken global is known to not be escaped from any function. It is
-// also incorrect for a transformation to introduce an escape of a global in
-// a way that is observable when it was not there previously. One function
-// being transformed to introduce an escape which could possibly be observed
-// (via loading from a global or the return value for example) within another
-// function is never safe. If the observation is made through non-atomic
-// operations on different threads, it is a data-race and UB. If the
-// observation is well defined, by being observed the transformation would have
-// changed program behavior by introducing the observed escape, making it an
-// invalid transform.
-//
-// This property does require that transformations which *temporarily* escape
-// a global that was not previously escaped, prior to restoring it, cannot rely
-// on the results of GMR::alias. This seems a reasonable restriction, although
-// currently there is no way to enforce it. There is also no realistic
-// optimization pass that would make this mistake. The closest example is
-// a transformation pass which does reg2mem of SSA values but stores them into
-// global variables temporarily before restoring the global variable's value.
-// This could be useful to expose "benign" races for example. However, it seems
-// reasonable to require that a pass which introduces escapes of global
-// variables in this way to either not trust AA results while the escape is
-// active, or to be forced to operate as a module pass that cannot co-exist
-// with an alias analysis such as GMR.
-bool GlobalsModRef::isNonEscapingGlobalNoAlias(const GlobalValue *GV,
- const Value *V) {
- // In order to know that the underlying object cannot alias the
- // non-addr-taken global, we must know that it would have to be an escape.
- // Thus if the underlying object is a function argument, a load from
- // a global, or the return of a function, it cannot alias. We can also
- // recurse through PHI nodes and select nodes provided all of their inputs
- // resolve to one of these known-escaping roots.
- SmallPtrSet<const Value *, 8> Visited;
- SmallVector<const Value *, 8> Inputs;
- Visited.insert(V);
- Inputs.push_back(V);
- int Depth = 0;
- do {
- const Value *Input = Inputs.pop_back_val();
-
- if (auto *InputGV = dyn_cast<GlobalValue>(Input)) {
- // If one input is the very global we're querying against, then we can't
- // conclude no-alias.
- if (InputGV == GV)
- return false;
-
- // Distinct GlobalVariables never alias, unless overriden or zero-sized.
- // FIXME: The condition can be refined, but be conservative for now.
- auto *GVar = dyn_cast<GlobalVariable>(GV);
- auto *InputGVar = dyn_cast<GlobalVariable>(InputGV);
- if (GVar && InputGVar &&
- !GVar->isDeclaration() && !InputGVar->isDeclaration() &&
- !GVar->mayBeOverridden() && !InputGVar->mayBeOverridden()) {
- Type *GVType = GVar->getInitializer()->getType();
- Type *InputGVType = InputGVar->getInitializer()->getType();
- if (GVType->isSized() && InputGVType->isSized() &&
- (DL->getTypeAllocSize(GVType) > 0) &&
- (DL->getTypeAllocSize(InputGVType) > 0))
- continue;
- }
-
- // Conservatively return false, even though we could be smarter
- // (e.g. look through GlobalAliases).
- return false;
- }
-
- if (isa<Argument>(Input) || isa<CallInst>(Input) ||
- isa<InvokeInst>(Input)) {
- // Arguments to functions or returns from functions are inherently
- // escaping, so we can immediately classify those as not aliasing any
- // non-addr-taken globals.
- continue;
- }
- if (auto *LI = dyn_cast<LoadInst>(Input)) {
- // A pointer loaded from a global would have been captured, and we know
- // that the global is non-escaping, so no alias.
- if (isa<GlobalValue>(GetUnderlyingObject(LI->getPointerOperand(), *DL)))
- continue;
-
- // Otherwise, a load could come from anywhere, so bail.
- return false;
- }
-
- // Recurse through a limited number of selects and PHIs. This is an
- // arbitrary depth of 4, lower numbers could be used to fix compile time
- // issues if needed, but this is generally expected to be only be important
- // for small depths.
- if (++Depth > 4)
- return false;
- if (auto *SI = dyn_cast<SelectInst>(Input)) {
- const Value *LHS = GetUnderlyingObject(SI->getTrueValue(), *DL);
- const Value *RHS = GetUnderlyingObject(SI->getFalseValue(), *DL);
- if (Visited.insert(LHS).second)
- Inputs.push_back(LHS);
- if (Visited.insert(RHS).second)
- Inputs.push_back(RHS);
- continue;
- }
- if (auto *PN = dyn_cast<PHINode>(Input)) {
- for (const Value *Op : PN->incoming_values()) {
- Op = GetUnderlyingObject(Op, *DL);
- if (Visited.insert(Op).second)
- Inputs.push_back(Op);
- }
- continue;
- }
-
- // FIXME: It would be good to handle other obvious no-alias cases here, but
- // it isn't clear how to do so reasonbly without building a small version
- // of BasicAA into this code. We could recurse into AliasAnalysis::alias
- // here but that seems likely to go poorly as we're inside the
- // implementation of such a query. Until then, just conservatievly retun
- // false.
- return false;
- } while (!Inputs.empty());
-
- // If all the inputs to V were definitively no-alias, then V is no-alias.
- return true;
-}
-
-/// alias - If one of the pointers is to a global that we are tracking, and the
-/// other is some random pointer, we know there cannot be an alias, because the
-/// address of the global isn't taken.
-AliasResult GlobalsModRef::alias(const MemoryLocation &LocA,
- const MemoryLocation &LocB) {
- // Get the base object these pointers point to.
- const Value *UV1 = GetUnderlyingObject(LocA.Ptr, *DL);
- const Value *UV2 = GetUnderlyingObject(LocB.Ptr, *DL);
-
- // If either of the underlying values is a global, they may be non-addr-taken
- // globals, which we can answer queries about.
- const GlobalValue *GV1 = dyn_cast<GlobalValue>(UV1);
- const GlobalValue *GV2 = dyn_cast<GlobalValue>(UV2);
- if (GV1 || GV2) {
- // If the global's address is taken, pretend we don't know it's a pointer to
- // the global.
- if (GV1 && !NonAddressTakenGlobals.count(GV1))
- GV1 = nullptr;
- if (GV2 && !NonAddressTakenGlobals.count(GV2))
- GV2 = nullptr;
-
- // If the two pointers are derived from two different non-addr-taken
- // globals we know these can't alias.
- if (GV1 && GV2 && GV1 != GV2)
- return NoAlias;
-
- // If one is and the other isn't, it isn't strictly safe but we can fake
- // this result if necessary for performance. This does not appear to be
- // a common problem in practice.
- if (EnableUnsafeGlobalsModRefAliasResults)
- if ((GV1 || GV2) && GV1 != GV2)
- return NoAlias;
-
- // Check for a special case where a non-escaping global can be used to
- // conclude no-alias.
- if ((GV1 || GV2) && GV1 != GV2) {
- const GlobalValue *GV = GV1 ? GV1 : GV2;
- const Value *UV = GV1 ? UV2 : UV1;
- if (isNonEscapingGlobalNoAlias(GV, UV))
- return NoAlias;
- }
-
- // Otherwise if they are both derived from the same addr-taken global, we
- // can't know the two accesses don't overlap.
- }
-
- // These pointers may be based on the memory owned by an indirect global. If
- // so, we may be able to handle this. First check to see if the base pointer
- // is a direct load from an indirect global.
- GV1 = GV2 = nullptr;
- if (const LoadInst *LI = dyn_cast<LoadInst>(UV1))
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
- if (IndirectGlobals.count(GV))
- GV1 = GV;
- if (const LoadInst *LI = dyn_cast<LoadInst>(UV2))
- if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(LI->getOperand(0)))
- if (IndirectGlobals.count(GV))
- GV2 = GV;
-
- // These pointers may also be from an allocation for the indirect global. If
- // so, also handle them.
- if (!GV1)
- GV1 = AllocsForIndirectGlobals.lookup(UV1);
- if (!GV2)
- GV2 = AllocsForIndirectGlobals.lookup(UV2);
-
- // Now that we know whether the two pointers are related to indirect globals,
- // use this to disambiguate the pointers. If the pointers are based on
- // different indirect globals they cannot alias.
- if (GV1 && GV2 && GV1 != GV2)
- return NoAlias;
-
- // If one is based on an indirect global and the other isn't, it isn't
- // strictly safe but we can fake this result if necessary for performance.
- // This does not appear to be a common problem in practice.
- if (EnableUnsafeGlobalsModRefAliasResults)
- if ((GV1 || GV2) && GV1 != GV2)
- return NoAlias;
-
- return AliasAnalysis::alias(LocA, LocB);
-}
-
-ModRefInfo GlobalsModRef::getModRefInfo(ImmutableCallSite CS,
- const MemoryLocation &Loc) {
- unsigned Known = MRI_ModRef;
-
- // If we are asking for mod/ref info of a direct call with a pointer to a
- // global we are tracking, return information if we have it.
- const DataLayout &DL = CS.getCaller()->getParent()->getDataLayout();
- if (const GlobalValue *GV =
- dyn_cast<GlobalValue>(GetUnderlyingObject(Loc.Ptr, DL)))
- if (GV->hasLocalLinkage())
- if (const Function *F = CS.getCalledFunction())
- if (NonAddressTakenGlobals.count(GV))
- if (const FunctionInfo *FI = getFunctionInfo(F))
- Known = FI->getModRefInfoForGlobal(*GV);
-
- if (Known == MRI_NoModRef)
- return MRI_NoModRef; // No need to query other mod/ref analyses
- return ModRefInfo(Known & AliasAnalysis::getModRefInfo(CS, Loc));
-}
+++ /dev/null
-//===-- IPA.cpp -----------------------------------------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the common initialization routines for the IPA library.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/InitializePasses.h"
-#include "llvm-c/Initialization.h"
-#include "llvm/PassRegistry.h"
-
-using namespace llvm;
-
-/// initializeIPA - Initialize all passes linked into the IPA library.
-void llvm::initializeIPA(PassRegistry &Registry) {
- initializeCallGraphWrapperPassPass(Registry);
- initializeCallGraphPrinterPass(Registry);
- initializeCallGraphViewerPass(Registry);
- initializeGlobalsModRefPass(Registry);
-}
-
-void LLVMInitializeIPA(LLVMPassRegistryRef R) {
- initializeIPA(*unwrap(R));
-}
+++ /dev/null
-//===- InlineCost.cpp - Cost analysis for inliner -------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements inline cost analysis.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/InlineCost.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/CodeMetrics.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/CallingConv.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/GetElementPtrTypeIterator.h"
-#include "llvm/IR/GlobalAlias.h"
-#include "llvm/IR/InstVisitor.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Operator.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "inline-cost"
-
-STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
-
-namespace {
-
-class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
- typedef InstVisitor<CallAnalyzer, bool> Base;
- friend class InstVisitor<CallAnalyzer, bool>;
-
- /// The TargetTransformInfo available for this compilation.
- const TargetTransformInfo &TTI;
-
- /// The cache of @llvm.assume intrinsics.
- AssumptionCacheTracker *ACT;
-
- // The called function.
- Function &F;
-
- // The candidate callsite being analyzed. Please do not use this to do
- // analysis in the caller function; we want the inline cost query to be
- // easily cacheable. Instead, use the cover function paramHasAttr.
- CallSite CandidateCS;
-
- int Threshold;
- int Cost;
-
- bool IsCallerRecursive;
- bool IsRecursiveCall;
- bool ExposesReturnsTwice;
- bool HasDynamicAlloca;
- bool ContainsNoDuplicateCall;
- bool HasReturn;
- bool HasIndirectBr;
- bool HasFrameEscape;
-
- /// Number of bytes allocated statically by the callee.
- uint64_t AllocatedSize;
- unsigned NumInstructions, NumVectorInstructions;
- int FiftyPercentVectorBonus, TenPercentVectorBonus;
- int VectorBonus;
-
- // While we walk the potentially-inlined instructions, we build up and
- // maintain a mapping of simplified values specific to this callsite. The
- // idea is to propagate any special information we have about arguments to
- // this call through the inlinable section of the function, and account for
- // likely simplifications post-inlining. The most important aspect we track
- // is CFG altering simplifications -- when we prove a basic block dead, that
- // can cause dramatic shifts in the cost of inlining a function.
- DenseMap<Value *, Constant *> SimplifiedValues;
-
- // Keep track of the values which map back (through function arguments) to
- // allocas on the caller stack which could be simplified through SROA.
- DenseMap<Value *, Value *> SROAArgValues;
-
- // The mapping of caller Alloca values to their accumulated cost savings. If
- // we have to disable SROA for one of the allocas, this tells us how much
- // cost must be added.
- DenseMap<Value *, int> SROAArgCosts;
-
- // Keep track of values which map to a pointer base and constant offset.
- DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs;
-
- // Custom simplification helper routines.
- bool isAllocaDerivedArg(Value *V);
- bool lookupSROAArgAndCost(Value *V, Value *&Arg,
- DenseMap<Value *, int>::iterator &CostIt);
- void disableSROA(DenseMap<Value *, int>::iterator CostIt);
- void disableSROA(Value *V);
- void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
- int InstructionCost);
- bool isGEPOffsetConstant(GetElementPtrInst &GEP);
- bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
- bool simplifyCallSite(Function *F, CallSite CS);
- ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V);
-
- /// Return true if the given argument to the function being considered for
- /// inlining has the given attribute set either at the call site or the
- /// function declaration. Primarily used to inspect call site specific
- /// attributes since these can be more precise than the ones on the callee
- /// itself.
- bool paramHasAttr(Argument *A, Attribute::AttrKind Attr);
-
- /// Return true if the given value is known non null within the callee if
- /// inlined through this particular callsite.
- bool isKnownNonNullInCallee(Value *V);
-
- // Custom analysis routines.
- bool analyzeBlock(BasicBlock *BB, SmallPtrSetImpl<const Value *> &EphValues);
-
- // Disable several entry points to the visitor so we don't accidentally use
- // them by declaring but not defining them here.
- void visit(Module *); void visit(Module &);
- void visit(Function *); void visit(Function &);
- void visit(BasicBlock *); void visit(BasicBlock &);
-
- // Provide base case for our instruction visit.
- bool visitInstruction(Instruction &I);
-
- // Our visit overrides.
- bool visitAlloca(AllocaInst &I);
- bool visitPHI(PHINode &I);
- bool visitGetElementPtr(GetElementPtrInst &I);
- bool visitBitCast(BitCastInst &I);
- bool visitPtrToInt(PtrToIntInst &I);
- bool visitIntToPtr(IntToPtrInst &I);
- bool visitCastInst(CastInst &I);
- bool visitUnaryInstruction(UnaryInstruction &I);
- bool visitCmpInst(CmpInst &I);
- bool visitSub(BinaryOperator &I);
- bool visitBinaryOperator(BinaryOperator &I);
- bool visitLoad(LoadInst &I);
- bool visitStore(StoreInst &I);
- bool visitExtractValue(ExtractValueInst &I);
- bool visitInsertValue(InsertValueInst &I);
- bool visitCallSite(CallSite CS);
- bool visitReturnInst(ReturnInst &RI);
- bool visitBranchInst(BranchInst &BI);
- bool visitSwitchInst(SwitchInst &SI);
- bool visitIndirectBrInst(IndirectBrInst &IBI);
- bool visitResumeInst(ResumeInst &RI);
- bool visitCleanupReturnInst(CleanupReturnInst &RI);
- bool visitCatchReturnInst(CatchReturnInst &RI);
- bool visitUnreachableInst(UnreachableInst &I);
-
-public:
- CallAnalyzer(const TargetTransformInfo &TTI, AssumptionCacheTracker *ACT,
- Function &Callee, int Threshold, CallSite CSArg)
- : TTI(TTI), ACT(ACT), F(Callee), CandidateCS(CSArg), Threshold(Threshold),
- Cost(0), IsCallerRecursive(false), IsRecursiveCall(false),
- ExposesReturnsTwice(false), HasDynamicAlloca(false),
- ContainsNoDuplicateCall(false), HasReturn(false), HasIndirectBr(false),
- HasFrameEscape(false), AllocatedSize(0), NumInstructions(0),
- NumVectorInstructions(0), FiftyPercentVectorBonus(0),
- TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
- NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
- NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
- SROACostSavings(0), SROACostSavingsLost(0) {}
-
- bool analyzeCall(CallSite CS);
-
- int getThreshold() { return Threshold; }
- int getCost() { return Cost; }
-
- // Keep a bunch of stats about the cost savings found so we can print them
- // out when debugging.
- unsigned NumConstantArgs;
- unsigned NumConstantOffsetPtrArgs;
- unsigned NumAllocaArgs;
- unsigned NumConstantPtrCmps;
- unsigned NumConstantPtrDiffs;
- unsigned NumInstructionsSimplified;
- unsigned SROACostSavings;
- unsigned SROACostSavingsLost;
-
- void dump();
-};
-
-} // namespace
-
-/// \brief Test whether the given value is an Alloca-derived function argument.
-bool CallAnalyzer::isAllocaDerivedArg(Value *V) {
- return SROAArgValues.count(V);
-}
-
-/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to.
-/// Returns false if V does not map to a SROA-candidate.
-bool CallAnalyzer::lookupSROAArgAndCost(
- Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) {
- if (SROAArgValues.empty() || SROAArgCosts.empty())
- return false;
-
- DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V);
- if (ArgIt == SROAArgValues.end())
- return false;
-
- Arg = ArgIt->second;
- CostIt = SROAArgCosts.find(Arg);
- return CostIt != SROAArgCosts.end();
-}
-
-/// \brief Disable SROA for the candidate marked by this cost iterator.
-///
-/// This marks the candidate as no longer viable for SROA, and adds the cost
-/// savings associated with it back into the inline cost measurement.
-void CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) {
- // If we're no longer able to perform SROA we need to undo its cost savings
- // and prevent subsequent analysis.
- Cost += CostIt->second;
- SROACostSavings -= CostIt->second;
- SROACostSavingsLost += CostIt->second;
- SROAArgCosts.erase(CostIt);
-}
-
-/// \brief If 'V' maps to a SROA candidate, disable SROA for it.
-void CallAnalyzer::disableSROA(Value *V) {
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(V, SROAArg, CostIt))
- disableSROA(CostIt);
-}
-
-/// \brief Accumulate the given cost for a particular SROA candidate.
-void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
- int InstructionCost) {
- CostIt->second += InstructionCost;
- SROACostSavings += InstructionCost;
-}
-
-/// \brief Check whether a GEP's indices are all constant.
-///
-/// Respects any simplified values known during the analysis of this callsite.
-bool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) {
- for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I)
- if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I))
- return false;
-
- return true;
-}
-
-/// \brief Accumulate a constant GEP offset into an APInt if possible.
-///
-/// Returns false if unable to compute the offset for any reason. Respects any
-/// simplified values known during the analysis of this callsite.
-bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
- const DataLayout &DL = F.getParent()->getDataLayout();
- unsigned IntPtrWidth = DL.getPointerSizeInBits();
- assert(IntPtrWidth == Offset.getBitWidth());
-
- for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
- GTI != GTE; ++GTI) {
- ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
- if (!OpC)
- if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand()))
- OpC = dyn_cast<ConstantInt>(SimpleOp);
- if (!OpC)
- return false;
- if (OpC->isZero()) continue;
-
- // Handle a struct index, which adds its field offset to the pointer.
- if (StructType *STy = dyn_cast<StructType>(*GTI)) {
- unsigned ElementIdx = OpC->getZExtValue();
- const StructLayout *SL = DL.getStructLayout(STy);
- Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
- continue;
- }
-
- APInt TypeSize(IntPtrWidth, DL.getTypeAllocSize(GTI.getIndexedType()));
- Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
- }
- return true;
-}
-
-bool CallAnalyzer::visitAlloca(AllocaInst &I) {
- // Check whether inlining will turn a dynamic alloca into a static
- // alloca, and handle that case.
- if (I.isArrayAllocation()) {
- if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
- ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
- assert(AllocSize && "Allocation size not a constant int?");
- Type *Ty = I.getAllocatedType();
- AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
- return Base::visitAlloca(I);
- }
- }
-
- // Accumulate the allocated size.
- if (I.isStaticAlloca()) {
- const DataLayout &DL = F.getParent()->getDataLayout();
- Type *Ty = I.getAllocatedType();
- AllocatedSize += DL.getTypeAllocSize(Ty);
- }
-
- // We will happily inline static alloca instructions.
- if (I.isStaticAlloca())
- return Base::visitAlloca(I);
-
- // FIXME: This is overly conservative. Dynamic allocas are inefficient for
- // a variety of reasons, and so we would like to not inline them into
- // functions which don't currently have a dynamic alloca. This simply
- // disables inlining altogether in the presence of a dynamic alloca.
- HasDynamicAlloca = true;
- return false;
-}
-
-bool CallAnalyzer::visitPHI(PHINode &I) {
- // FIXME: We should potentially be tracking values through phi nodes,
- // especially when they collapse to a single value due to deleted CFG edges
- // during inlining.
-
- // FIXME: We need to propagate SROA *disabling* through phi nodes, even
- // though we don't want to propagate it's bonuses. The idea is to disable
- // SROA if it *might* be used in an inappropriate manner.
-
- // Phi nodes are always zero-cost.
- return true;
-}
-
-bool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) {
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(),
- SROAArg, CostIt);
-
- // Try to fold GEPs of constant-offset call site argument pointers. This
- // requires target data and inbounds GEPs.
- if (I.isInBounds()) {
- // Check if we have a base + offset for the pointer.
- Value *Ptr = I.getPointerOperand();
- std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr);
- if (BaseAndOffset.first) {
- // Check if the offset of this GEP is constant, and if so accumulate it
- // into Offset.
- if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) {
- // Non-constant GEPs aren't folded, and disable SROA.
- if (SROACandidate)
- disableSROA(CostIt);
- return false;
- }
-
- // Add the result as a new mapping to Base + Offset.
- ConstantOffsetPtrs[&I] = BaseAndOffset;
-
- // Also handle SROA candidates here, we already know that the GEP is
- // all-constant indexed.
- if (SROACandidate)
- SROAArgValues[&I] = SROAArg;
-
- return true;
- }
- }
-
- if (isGEPOffsetConstant(I)) {
- if (SROACandidate)
- SROAArgValues[&I] = SROAArg;
-
- // Constant GEPs are modeled as free.
- return true;
- }
-
- // Variable GEPs will require math and will disable SROA.
- if (SROACandidate)
- disableSROA(CostIt);
- return false;
-}
-
-bool CallAnalyzer::visitBitCast(BitCastInst &I) {
- // Propagate constants through bitcasts.
- Constant *COp = dyn_cast<Constant>(I.getOperand(0));
- if (!COp)
- COp = SimplifiedValues.lookup(I.getOperand(0));
- if (COp)
- if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) {
- SimplifiedValues[&I] = C;
- return true;
- }
-
- // Track base/offsets through casts
- std::pair<Value *, APInt> BaseAndOffset
- = ConstantOffsetPtrs.lookup(I.getOperand(0));
- // Casts don't change the offset, just wrap it up.
- if (BaseAndOffset.first)
- ConstantOffsetPtrs[&I] = BaseAndOffset;
-
- // Also look for SROA candidates here.
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
- SROAArgValues[&I] = SROAArg;
-
- // Bitcasts are always zero cost.
- return true;
-}
-
-bool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) {
- // Propagate constants through ptrtoint.
- Constant *COp = dyn_cast<Constant>(I.getOperand(0));
- if (!COp)
- COp = SimplifiedValues.lookup(I.getOperand(0));
- if (COp)
- if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) {
- SimplifiedValues[&I] = C;
- return true;
- }
-
- // Track base/offset pairs when converted to a plain integer provided the
- // integer is large enough to represent the pointer.
- unsigned IntegerSize = I.getType()->getScalarSizeInBits();
- const DataLayout &DL = F.getParent()->getDataLayout();
- if (IntegerSize >= DL.getPointerSizeInBits()) {
- std::pair<Value *, APInt> BaseAndOffset
- = ConstantOffsetPtrs.lookup(I.getOperand(0));
- if (BaseAndOffset.first)
- ConstantOffsetPtrs[&I] = BaseAndOffset;
- }
-
- // This is really weird. Technically, ptrtoint will disable SROA. However,
- // unless that ptrtoint is *used* somewhere in the live basic blocks after
- // inlining, it will be nuked, and SROA should proceed. All of the uses which
- // would block SROA would also block SROA if applied directly to a pointer,
- // and so we can just add the integer in here. The only places where SROA is
- // preserved either cannot fire on an integer, or won't in-and-of themselves
- // disable SROA (ext) w/o some later use that we would see and disable.
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
- SROAArgValues[&I] = SROAArg;
-
- return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) {
- // Propagate constants through ptrtoint.
- Constant *COp = dyn_cast<Constant>(I.getOperand(0));
- if (!COp)
- COp = SimplifiedValues.lookup(I.getOperand(0));
- if (COp)
- if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) {
- SimplifiedValues[&I] = C;
- return true;
- }
-
- // Track base/offset pairs when round-tripped through a pointer without
- // modifications provided the integer is not too large.
- Value *Op = I.getOperand(0);
- unsigned IntegerSize = Op->getType()->getScalarSizeInBits();
- const DataLayout &DL = F.getParent()->getDataLayout();
- if (IntegerSize <= DL.getPointerSizeInBits()) {
- std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op);
- if (BaseAndOffset.first)
- ConstantOffsetPtrs[&I] = BaseAndOffset;
- }
-
- // "Propagate" SROA here in the same manner as we do for ptrtoint above.
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(Op, SROAArg, CostIt))
- SROAArgValues[&I] = SROAArg;
-
- return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitCastInst(CastInst &I) {
- // Propagate constants through ptrtoint.
- Constant *COp = dyn_cast<Constant>(I.getOperand(0));
- if (!COp)
- COp = SimplifiedValues.lookup(I.getOperand(0));
- if (COp)
- if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) {
- SimplifiedValues[&I] = C;
- return true;
- }
-
- // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere.
- disableSROA(I.getOperand(0));
-
- return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
-}
-
-bool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) {
- Value *Operand = I.getOperand(0);
- Constant *COp = dyn_cast<Constant>(Operand);
- if (!COp)
- COp = SimplifiedValues.lookup(Operand);
- if (COp) {
- const DataLayout &DL = F.getParent()->getDataLayout();
- if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(),
- COp, DL)) {
- SimplifiedValues[&I] = C;
- return true;
- }
- }
-
- // Disable any SROA on the argument to arbitrary unary operators.
- disableSROA(Operand);
-
- return false;
-}
-
-bool CallAnalyzer::paramHasAttr(Argument *A, Attribute::AttrKind Attr) {
- unsigned ArgNo = A->getArgNo();
- return CandidateCS.paramHasAttr(ArgNo+1, Attr);
-}
-
-bool CallAnalyzer::isKnownNonNullInCallee(Value *V) {
- // Does the *call site* have the NonNull attribute set on an argument? We
- // use the attribute on the call site to memoize any analysis done in the
- // caller. This will also trip if the callee function has a non-null
- // parameter attribute, but that's a less interesting case because hopefully
- // the callee would already have been simplified based on that.
- if (Argument *A = dyn_cast<Argument>(V))
- if (paramHasAttr(A, Attribute::NonNull))
- return true;
-
- // Is this an alloca in the caller? This is distinct from the attribute case
- // above because attributes aren't updated within the inliner itself and we
- // always want to catch the alloca derived case.
- if (isAllocaDerivedArg(V))
- // We can actually predict the result of comparisons between an
- // alloca-derived value and null. Note that this fires regardless of
- // SROA firing.
- return true;
-
- return false;
-}
-
-bool CallAnalyzer::visitCmpInst(CmpInst &I) {
- Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
- // First try to handle simplified comparisons.
- if (!isa<Constant>(LHS))
- if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
- LHS = SimpleLHS;
- if (!isa<Constant>(RHS))
- if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
- RHS = SimpleRHS;
- if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
- if (Constant *CRHS = dyn_cast<Constant>(RHS))
- if (Constant *C = ConstantExpr::getCompare(I.getPredicate(), CLHS, CRHS)) {
- SimplifiedValues[&I] = C;
- return true;
- }
- }
-
- if (I.getOpcode() == Instruction::FCmp)
- return false;
-
- // Otherwise look for a comparison between constant offset pointers with
- // a common base.
- Value *LHSBase, *RHSBase;
- APInt LHSOffset, RHSOffset;
- std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
- if (LHSBase) {
- std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
- if (RHSBase && LHSBase == RHSBase) {
- // We have common bases, fold the icmp to a constant based on the
- // offsets.
- Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
- Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
- if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
- SimplifiedValues[&I] = C;
- ++NumConstantPtrCmps;
- return true;
- }
- }
- }
-
- // If the comparison is an equality comparison with null, we can simplify it
- // if we know the value (argument) can't be null
- if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)) &&
- isKnownNonNullInCallee(I.getOperand(0))) {
- bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
- SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
- : ConstantInt::getFalse(I.getType());
- return true;
- }
- // Finally check for SROA candidates in comparisons.
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
- if (isa<ConstantPointerNull>(I.getOperand(1))) {
- accumulateSROACost(CostIt, InlineConstants::InstrCost);
- return true;
- }
-
- disableSROA(CostIt);
- }
-
- return false;
-}
-
-bool CallAnalyzer::visitSub(BinaryOperator &I) {
- // Try to handle a special case: we can fold computing the difference of two
- // constant-related pointers.
- Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
- Value *LHSBase, *RHSBase;
- APInt LHSOffset, RHSOffset;
- std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
- if (LHSBase) {
- std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
- if (RHSBase && LHSBase == RHSBase) {
- // We have common bases, fold the subtract to a constant based on the
- // offsets.
- Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
- Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
- if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) {
- SimplifiedValues[&I] = C;
- ++NumConstantPtrDiffs;
- return true;
- }
- }
- }
-
- // Otherwise, fall back to the generic logic for simplifying and handling
- // instructions.
- return Base::visitSub(I);
-}
-
-bool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) {
- Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
- const DataLayout &DL = F.getParent()->getDataLayout();
- if (!isa<Constant>(LHS))
- if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
- LHS = SimpleLHS;
- if (!isa<Constant>(RHS))
- if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
- RHS = SimpleRHS;
- Value *SimpleV = nullptr;
- if (auto FI = dyn_cast<FPMathOperator>(&I))
- SimpleV =
- SimplifyFPBinOp(I.getOpcode(), LHS, RHS, FI->getFastMathFlags(), DL);
- else
- SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
-
- if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
- SimplifiedValues[&I] = C;
- return true;
- }
-
- // Disable any SROA on arguments to arbitrary, unsimplified binary operators.
- disableSROA(LHS);
- disableSROA(RHS);
-
- return false;
-}
-
-bool CallAnalyzer::visitLoad(LoadInst &I) {
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
- if (I.isSimple()) {
- accumulateSROACost(CostIt, InlineConstants::InstrCost);
- return true;
- }
-
- disableSROA(CostIt);
- }
-
- return false;
-}
-
-bool CallAnalyzer::visitStore(StoreInst &I) {
- Value *SROAArg;
- DenseMap<Value *, int>::iterator CostIt;
- if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
- if (I.isSimple()) {
- accumulateSROACost(CostIt, InlineConstants::InstrCost);
- return true;
- }
-
- disableSROA(CostIt);
- }
-
- return false;
-}
-
-bool CallAnalyzer::visitExtractValue(ExtractValueInst &I) {
- // Constant folding for extract value is trivial.
- Constant *C = dyn_cast<Constant>(I.getAggregateOperand());
- if (!C)
- C = SimplifiedValues.lookup(I.getAggregateOperand());
- if (C) {
- SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices());
- return true;
- }
-
- // SROA can look through these but give them a cost.
- return false;
-}
-
-bool CallAnalyzer::visitInsertValue(InsertValueInst &I) {
- // Constant folding for insert value is trivial.
- Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand());
- if (!AggC)
- AggC = SimplifiedValues.lookup(I.getAggregateOperand());
- Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand());
- if (!InsertedC)
- InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand());
- if (AggC && InsertedC) {
- SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC,
- I.getIndices());
- return true;
- }
-
- // SROA can look through these but give them a cost.
- return false;
-}
-
-/// \brief Try to simplify a call site.
-///
-/// Takes a concrete function and callsite and tries to actually simplify it by
-/// analyzing the arguments and call itself with instsimplify. Returns true if
-/// it has simplified the callsite to some other entity (a constant), making it
-/// free.
-bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
- // FIXME: Using the instsimplify logic directly for this is inefficient
- // because we have to continually rebuild the argument list even when no
- // simplifications can be performed. Until that is fixed with remapping
- // inside of instsimplify, directly constant fold calls here.
- if (!canConstantFoldCallTo(F))
- return false;
-
- // Try to re-map the arguments to constants.
- SmallVector<Constant *, 4> ConstantArgs;
- ConstantArgs.reserve(CS.arg_size());
- for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
- I != E; ++I) {
- Constant *C = dyn_cast<Constant>(*I);
- if (!C)
- C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
- if (!C)
- return false; // This argument doesn't map to a constant.
-
- ConstantArgs.push_back(C);
- }
- if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
- SimplifiedValues[CS.getInstruction()] = C;
- return true;
- }
-
- return false;
-}
-
-bool CallAnalyzer::visitCallSite(CallSite CS) {
- if (CS.hasFnAttr(Attribute::ReturnsTwice) &&
- !F.hasFnAttribute(Attribute::ReturnsTwice)) {
- // This aborts the entire analysis.
- ExposesReturnsTwice = true;
- return false;
- }
- if (CS.isCall() &&
- cast<CallInst>(CS.getInstruction())->cannotDuplicate())
- ContainsNoDuplicateCall = true;
-
- if (Function *F = CS.getCalledFunction()) {
- // When we have a concrete function, first try to simplify it directly.
- if (simplifyCallSite(F, CS))
- return true;
-
- // Next check if it is an intrinsic we know about.
- // FIXME: Lift this into part of the InstVisitor.
- if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
- switch (II->getIntrinsicID()) {
- default:
- return Base::visitCallSite(CS);
-
- case Intrinsic::memset:
- case Intrinsic::memcpy:
- case Intrinsic::memmove:
- // SROA can usually chew through these intrinsics, but they aren't free.
- return false;
- case Intrinsic::localescape:
- HasFrameEscape = true;
- return false;
- }
- }
-
- if (F == CS.getInstruction()->getParent()->getParent()) {
- // This flag will fully abort the analysis, so don't bother with anything
- // else.
- IsRecursiveCall = true;
- return false;
- }
-
- if (TTI.isLoweredToCall(F)) {
- // We account for the average 1 instruction per call argument setup
- // here.
- Cost += CS.arg_size() * InlineConstants::InstrCost;
-
- // Everything other than inline ASM will also have a significant cost
- // merely from making the call.
- if (!isa<InlineAsm>(CS.getCalledValue()))
- Cost += InlineConstants::CallPenalty;
- }
-
- return Base::visitCallSite(CS);
- }
-
- // Otherwise we're in a very special case -- an indirect function call. See
- // if we can be particularly clever about this.
- Value *Callee = CS.getCalledValue();
-
- // First, pay the price of the argument setup. We account for the average
- // 1 instruction per call argument setup here.
- Cost += CS.arg_size() * InlineConstants::InstrCost;
-
- // Next, check if this happens to be an indirect function call to a known
- // function in this inline context. If not, we've done all we can.
- Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee));
- if (!F)
- return Base::visitCallSite(CS);
-
- // If we have a constant that we are calling as a function, we can peer
- // through it and see the function target. This happens not infrequently
- // during devirtualization and so we want to give it a hefty bonus for
- // inlining, but cap that bonus in the event that inlining wouldn't pan
- // out. Pretend to inline the function, with a custom threshold.
- CallAnalyzer CA(TTI, ACT, *F, InlineConstants::IndirectCallThreshold, CS);
- if (CA.analyzeCall(CS)) {
- // We were able to inline the indirect call! Subtract the cost from the
- // bonus we want to apply, but don't go below zero.
- Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost());
- }
-
- return Base::visitCallSite(CS);
-}
-
-bool CallAnalyzer::visitReturnInst(ReturnInst &RI) {
- // At least one return instruction will be free after inlining.
- bool Free = !HasReturn;
- HasReturn = true;
- return Free;
-}
-
-bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
- // We model unconditional branches as essentially free -- they really
- // shouldn't exist at all, but handling them makes the behavior of the
- // inliner more regular and predictable. Interestingly, conditional branches
- // which will fold away are also free.
- return BI.isUnconditional() || isa<ConstantInt>(BI.getCondition()) ||
- dyn_cast_or_null<ConstantInt>(
- SimplifiedValues.lookup(BI.getCondition()));
-}
-
-bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
- // We model unconditional switches as free, see the comments on handling
- // branches.
- if (isa<ConstantInt>(SI.getCondition()))
- return true;
- if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
- if (isa<ConstantInt>(V))
- return true;
-
- // Otherwise, we need to accumulate a cost proportional to the number of
- // distinct successor blocks. This fan-out in the CFG cannot be represented
- // for free even if we can represent the core switch as a jumptable that
- // takes a single instruction.
- //
- // NB: We convert large switches which are just used to initialize large phi
- // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
- // inlining those. It will prevent inlining in cases where the optimization
- // does not (yet) fire.
- SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
- SuccessorBlocks.insert(SI.getDefaultDest());
- for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
- SuccessorBlocks.insert(I.getCaseSuccessor());
- // Add cost corresponding to the number of distinct destinations. The first
- // we model as free because of fallthrough.
- Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
- return false;
-}
-
-bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
- // We never want to inline functions that contain an indirectbr. This is
- // incorrect because all the blockaddress's (in static global initializers
- // for example) would be referring to the original function, and this
- // indirect jump would jump from the inlined copy of the function into the
- // original function which is extremely undefined behavior.
- // FIXME: This logic isn't really right; we can safely inline functions with
- // indirectbr's as long as no other function or global references the
- // blockaddress of a block within the current function.
- HasIndirectBr = true;
- return false;
-}
-
-bool CallAnalyzer::visitResumeInst(ResumeInst &RI) {
- // FIXME: It's not clear that a single instruction is an accurate model for
- // the inline cost of a resume instruction.
- return false;
-}
-
-bool CallAnalyzer::visitCleanupReturnInst(CleanupReturnInst &CRI) {
- // FIXME: It's not clear that a single instruction is an accurate model for
- // the inline cost of a cleanupret instruction.
- return false;
-}
-
-bool CallAnalyzer::visitCatchReturnInst(CatchReturnInst &CRI) {
- // FIXME: It's not clear that a single instruction is an accurate model for
- // the inline cost of a cleanupret instruction.
- return false;
-}
-
-bool CallAnalyzer::visitUnreachableInst(UnreachableInst &I) {
- // FIXME: It might be reasonably to discount the cost of instructions leading
- // to unreachable as they have the lowest possible impact on both runtime and
- // code size.
- return true; // No actual code is needed for unreachable.
-}
-
-bool CallAnalyzer::visitInstruction(Instruction &I) {
- // Some instructions are free. All of the free intrinsics can also be
- // handled by SROA, etc.
- if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I))
- return true;
-
- // We found something we don't understand or can't handle. Mark any SROA-able
- // values in the operand list as no longer viable.
- for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI)
- disableSROA(*OI);
-
- return false;
-}
-
-
-/// \brief Analyze a basic block for its contribution to the inline cost.
-///
-/// This method walks the analyzer over every instruction in the given basic
-/// block and accounts for their cost during inlining at this callsite. It
-/// aborts early if the threshold has been exceeded or an impossible to inline
-/// construct has been detected. It returns false if inlining is no longer
-/// viable, and true if inlining remains viable.
-bool CallAnalyzer::analyzeBlock(BasicBlock *BB,
- SmallPtrSetImpl<const Value *> &EphValues) {
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
- // FIXME: Currently, the number of instructions in a function regardless of
- // our ability to simplify them during inline to constants or dead code,
- // are actually used by the vector bonus heuristic. As long as that's true,
- // we have to special case debug intrinsics here to prevent differences in
- // inlining due to debug symbols. Eventually, the number of unsimplified
- // instructions shouldn't factor into the cost computation, but until then,
- // hack around it here.
- if (isa<DbgInfoIntrinsic>(I))
- continue;
-
- // Skip ephemeral values.
- if (EphValues.count(I))
- continue;
-
- ++NumInstructions;
- if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
- ++NumVectorInstructions;
-
- // If the instruction is floating point, and the target says this operation is
- // expensive or the function has the "use-soft-float" attribute, this may
- // eventually become a library call. Treat the cost as such.
- if (I->getType()->isFloatingPointTy()) {
- bool hasSoftFloatAttr = false;
-
- // If the function has the "use-soft-float" attribute, mark it as expensive.
- if (F.hasFnAttribute("use-soft-float")) {
- Attribute Attr = F.getFnAttribute("use-soft-float");
- StringRef Val = Attr.getValueAsString();
- if (Val == "true")
- hasSoftFloatAttr = true;
- }
-
- if (TTI.getFPOpCost(I->getType()) == TargetTransformInfo::TCC_Expensive ||
- hasSoftFloatAttr)
- Cost += InlineConstants::CallPenalty;
- }
-
- // If the instruction simplified to a constant, there is no cost to this
- // instruction. Visit the instructions using our InstVisitor to account for
- // all of the per-instruction logic. The visit tree returns true if we
- // consumed the instruction in any way, and false if the instruction's base
- // cost should count against inlining.
- if (Base::visit(I))
- ++NumInstructionsSimplified;
- else
- Cost += InlineConstants::InstrCost;
-
- // If the visit this instruction detected an uninlinable pattern, abort.
- if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
- HasIndirectBr || HasFrameEscape)
- return false;
-
- // If the caller is a recursive function then we don't want to inline
- // functions which allocate a lot of stack space because it would increase
- // the caller stack usage dramatically.
- if (IsCallerRecursive &&
- AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
- return false;
-
- // Check if we've past the maximum possible threshold so we don't spin in
- // huge basic blocks that will never inline.
- if (Cost > Threshold)
- return false;
- }
-
- return true;
-}
-
-/// \brief Compute the base pointer and cumulative constant offsets for V.
-///
-/// This strips all constant offsets off of V, leaving it the base pointer, and
-/// accumulates the total constant offset applied in the returned constant. It
-/// returns 0 if V is not a pointer, and returns the constant '0' if there are
-/// no constant offsets applied.
-ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
- if (!V->getType()->isPointerTy())
- return nullptr;
-
- const DataLayout &DL = F.getParent()->getDataLayout();
- unsigned IntPtrWidth = DL.getPointerSizeInBits();
- APInt Offset = APInt::getNullValue(IntPtrWidth);
-
- // Even though we don't look through PHI nodes, we could be called on an
- // instruction in an unreachable block, which may be on a cycle.
- SmallPtrSet<Value *, 4> Visited;
- Visited.insert(V);
- do {
- if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
- if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
- return nullptr;
- V = GEP->getPointerOperand();
- } else if (Operator::getOpcode(V) == Instruction::BitCast) {
- V = cast<Operator>(V)->getOperand(0);
- } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
- if (GA->mayBeOverridden())
- break;
- V = GA->getAliasee();
- } else {
- break;
- }
- assert(V->getType()->isPointerTy() && "Unexpected operand type!");
- } while (Visited.insert(V).second);
-
- Type *IntPtrTy = DL.getIntPtrType(V->getContext());
- return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset));
-}
-
-/// \brief Analyze a call site for potential inlining.
-///
-/// Returns true if inlining this call is viable, and false if it is not
-/// viable. It computes the cost and adjusts the threshold based on numerous
-/// factors and heuristics. If this method returns false but the computed cost
-/// is below the computed threshold, then inlining was forcibly disabled by
-/// some artifact of the routine.
-bool CallAnalyzer::analyzeCall(CallSite CS) {
- ++NumCallsAnalyzed;
-
- // Perform some tweaks to the cost and threshold based on the direct
- // callsite information.
-
- // We want to more aggressively inline vector-dense kernels, so up the
- // threshold, and we'll lower it if the % of vector instructions gets too
- // low. Note that these bonuses are some what arbitrary and evolved over time
- // by accident as much as because they are principled bonuses.
- //
- // FIXME: It would be nice to remove all such bonuses. At least it would be
- // nice to base the bonus values on something more scientific.
- assert(NumInstructions == 0);
- assert(NumVectorInstructions == 0);
- FiftyPercentVectorBonus = 3 * Threshold / 2;
- TenPercentVectorBonus = 3 * Threshold / 4;
- const DataLayout &DL = F.getParent()->getDataLayout();
-
- // Track whether the post-inlining function would have more than one basic
- // block. A single basic block is often intended for inlining. Balloon the
- // threshold by 50% until we pass the single-BB phase.
- bool SingleBB = true;
- int SingleBBBonus = Threshold / 2;
-
- // Speculatively apply all possible bonuses to Threshold. If cost exceeds
- // this Threshold any time, and cost cannot decrease, we can stop processing
- // the rest of the function body.
- Threshold += (SingleBBBonus + FiftyPercentVectorBonus);
-
- // Give out bonuses per argument, as the instructions setting them up will
- // be gone after inlining.
- for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) {
- if (CS.isByValArgument(I)) {
- // We approximate the number of loads and stores needed by dividing the
- // size of the byval type by the target's pointer size.
- PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType());
- unsigned TypeSize = DL.getTypeSizeInBits(PTy->getElementType());
- unsigned PointerSize = DL.getPointerSizeInBits();
- // Ceiling division.
- unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize;
-
- // If it generates more than 8 stores it is likely to be expanded as an
- // inline memcpy so we take that as an upper bound. Otherwise we assume
- // one load and one store per word copied.
- // FIXME: The maxStoresPerMemcpy setting from the target should be used
- // here instead of a magic number of 8, but it's not available via
- // DataLayout.
- NumStores = std::min(NumStores, 8U);
-
- Cost -= 2 * NumStores * InlineConstants::InstrCost;
- } else {
- // For non-byval arguments subtract off one instruction per call
- // argument.
- Cost -= InlineConstants::InstrCost;
- }
- }
-
- // If there is only one call of the function, and it has internal linkage,
- // the cost of inlining it drops dramatically.
- bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() &&
- &F == CS.getCalledFunction();
- if (OnlyOneCallAndLocalLinkage)
- Cost += InlineConstants::LastCallToStaticBonus;
-
- // If the instruction after the call, or if the normal destination of the
- // invoke is an unreachable instruction, the function is noreturn. As such,
- // there is little point in inlining this unless there is literally zero
- // cost.
- Instruction *Instr = CS.getInstruction();
- if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) {
- if (isa<UnreachableInst>(II->getNormalDest()->begin()))
- Threshold = 0;
- } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr)))
- Threshold = 0;
-
- // If this function uses the coldcc calling convention, prefer not to inline
- // it.
- if (F.getCallingConv() == CallingConv::Cold)
- Cost += InlineConstants::ColdccPenalty;
-
- // Check if we're done. This can happen due to bonuses and penalties.
- if (Cost > Threshold)
- return false;
-
- if (F.empty())
- return true;
-
- Function *Caller = CS.getInstruction()->getParent()->getParent();
- // Check if the caller function is recursive itself.
- for (User *U : Caller->users()) {
- CallSite Site(U);
- if (!Site)
- continue;
- Instruction *I = Site.getInstruction();
- if (I->getParent()->getParent() == Caller) {
- IsCallerRecursive = true;
- break;
- }
- }
-
- // Populate our simplified values by mapping from function arguments to call
- // arguments with known important simplifications.
- CallSite::arg_iterator CAI = CS.arg_begin();
- for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end();
- FAI != FAE; ++FAI, ++CAI) {
- assert(CAI != CS.arg_end());
- if (Constant *C = dyn_cast<Constant>(CAI))
- SimplifiedValues[FAI] = C;
-
- Value *PtrArg = *CAI;
- if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) {
- ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue());
-
- // We can SROA any pointer arguments derived from alloca instructions.
- if (isa<AllocaInst>(PtrArg)) {
- SROAArgValues[FAI] = PtrArg;
- SROAArgCosts[PtrArg] = 0;
- }
- }
- }
- NumConstantArgs = SimplifiedValues.size();
- NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size();
- NumAllocaArgs = SROAArgValues.size();
-
- // FIXME: If a caller has multiple calls to a callee, we end up recomputing
- // the ephemeral values multiple times (and they're completely determined by
- // the callee, so this is purely duplicate work).
- SmallPtrSet<const Value *, 32> EphValues;
- CodeMetrics::collectEphemeralValues(&F, &ACT->getAssumptionCache(F), EphValues);
-
- // The worklist of live basic blocks in the callee *after* inlining. We avoid
- // adding basic blocks of the callee which can be proven to be dead for this
- // particular call site in order to get more accurate cost estimates. This
- // requires a somewhat heavyweight iteration pattern: we need to walk the
- // basic blocks in a breadth-first order as we insert live successors. To
- // accomplish this, prioritizing for small iterations because we exit after
- // crossing our threshold, we use a small-size optimized SetVector.
- typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
- SmallPtrSet<BasicBlock *, 16> > BBSetVector;
- BBSetVector BBWorklist;
- BBWorklist.insert(&F.getEntryBlock());
- // Note that we *must not* cache the size, this loop grows the worklist.
- for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
- // Bail out the moment we cross the threshold. This means we'll under-count
- // the cost, but only when undercounting doesn't matter.
- if (Cost > Threshold)
- break;
-
- BasicBlock *BB = BBWorklist[Idx];
- if (BB->empty())
- continue;
-
- // Disallow inlining a blockaddress. A blockaddress only has defined
- // behavior for an indirect branch in the same function, and we do not
- // currently support inlining indirect branches. But, the inliner may not
- // see an indirect branch that ends up being dead code at a particular call
- // site. If the blockaddress escapes the function, e.g., via a global
- // variable, inlining may lead to an invalid cross-function reference.
- if (BB->hasAddressTaken())
- return false;
-
- // Analyze the cost of this block. If we blow through the threshold, this
- // returns false, and we can bail on out.
- if (!analyzeBlock(BB, EphValues)) {
- if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
- HasIndirectBr || HasFrameEscape)
- return false;
-
- // If the caller is a recursive function then we don't want to inline
- // functions which allocate a lot of stack space because it would increase
- // the caller stack usage dramatically.
- if (IsCallerRecursive &&
- AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
- return false;
-
- break;
- }
-
- TerminatorInst *TI = BB->getTerminator();
-
- // Add in the live successors by first checking whether we have terminator
- // that may be simplified based on the values simplified by this call.
- if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
- if (BI->isConditional()) {
- Value *Cond = BI->getCondition();
- if (ConstantInt *SimpleCond
- = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
- BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0));
- continue;
- }
- }
- } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
- Value *Cond = SI->getCondition();
- if (ConstantInt *SimpleCond
- = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
- BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor());
- continue;
- }
- }
-
- // If we're unable to select a particular successor, just count all of
- // them.
- for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize;
- ++TIdx)
- BBWorklist.insert(TI->getSuccessor(TIdx));
-
- // If we had any successors at this point, than post-inlining is likely to
- // have them as well. Note that we assume any basic blocks which existed
- // due to branches or switches which folded above will also fold after
- // inlining.
- if (SingleBB && TI->getNumSuccessors() > 1) {
- // Take off the bonus we applied to the threshold.
- Threshold -= SingleBBBonus;
- SingleBB = false;
- }
- }
-
- // If this is a noduplicate call, we can still inline as long as
- // inlining this would cause the removal of the caller (so the instruction
- // is not actually duplicated, just moved).
- if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
- return false;
-
- // We applied the maximum possible vector bonus at the beginning. Now,
- // subtract the excess bonus, if any, from the Threshold before
- // comparing against Cost.
- if (NumVectorInstructions <= NumInstructions / 10)
- Threshold -= FiftyPercentVectorBonus;
- else if (NumVectorInstructions <= NumInstructions / 2)
- Threshold -= (FiftyPercentVectorBonus - TenPercentVectorBonus);
-
- return Cost < Threshold;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-/// \brief Dump stats about this call's analysis.
-void CallAnalyzer::dump() {
-#define DEBUG_PRINT_STAT(x) dbgs() << " " #x ": " << x << "\n"
- DEBUG_PRINT_STAT(NumConstantArgs);
- DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs);
- DEBUG_PRINT_STAT(NumAllocaArgs);
- DEBUG_PRINT_STAT(NumConstantPtrCmps);
- DEBUG_PRINT_STAT(NumConstantPtrDiffs);
- DEBUG_PRINT_STAT(NumInstructionsSimplified);
- DEBUG_PRINT_STAT(NumInstructions);
- DEBUG_PRINT_STAT(SROACostSavings);
- DEBUG_PRINT_STAT(SROACostSavingsLost);
- DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
- DEBUG_PRINT_STAT(Cost);
- DEBUG_PRINT_STAT(Threshold);
-#undef DEBUG_PRINT_STAT
-}
-#endif
-
-INITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
- true, true)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
- true, true)
-
-char InlineCostAnalysis::ID = 0;
-
-InlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID) {}
-
-InlineCostAnalysis::~InlineCostAnalysis() {}
-
-void InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesAll();
- AU.addRequired<AssumptionCacheTracker>();
- AU.addRequired<TargetTransformInfoWrapperPass>();
- CallGraphSCCPass::getAnalysisUsage(AU);
-}
-
-bool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) {
- TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
- ACT = &getAnalysis<AssumptionCacheTracker>();
- return false;
-}
-
-InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
- return getInlineCost(CS, CS.getCalledFunction(), Threshold);
-}
-
-/// \brief Test that two functions either have or have not the given attribute
-/// at the same time.
-template<typename AttrKind>
-static bool attributeMatches(Function *F1, Function *F2, AttrKind Attr) {
- return F1->getFnAttribute(Attr) == F2->getFnAttribute(Attr);
-}
-
-/// \brief Test that there are no attribute conflicts between Caller and Callee
-/// that prevent inlining.
-static bool functionsHaveCompatibleAttributes(Function *Caller,
- Function *Callee,
- TargetTransformInfo &TTI) {
- return TTI.areInlineCompatible(Caller, Callee) &&
- attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
- attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
- attributeMatches(Caller, Callee, Attribute::SanitizeThread);
-}
-
-InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
- int Threshold) {
- // Cannot inline indirect calls.
- if (!Callee)
- return llvm::InlineCost::getNever();
-
- // Calls to functions with always-inline attributes should be inlined
- // whenever possible.
- if (CS.hasFnAttr(Attribute::AlwaysInline)) {
- if (isInlineViable(*Callee))
- return llvm::InlineCost::getAlways();
- return llvm::InlineCost::getNever();
- }
-
- // Never inline functions with conflicting attributes (unless callee has
- // always-inline attribute).
- if (!functionsHaveCompatibleAttributes(CS.getCaller(), Callee,
- TTIWP->getTTI(*Callee)))
- return llvm::InlineCost::getNever();
-
- // Don't inline this call if the caller has the optnone attribute.
- if (CS.getCaller()->hasFnAttribute(Attribute::OptimizeNone))
- return llvm::InlineCost::getNever();
-
- // Don't inline functions which can be redefined at link-time to mean
- // something else. Don't inline functions marked noinline or call sites
- // marked noinline.
- if (Callee->mayBeOverridden() ||
- Callee->hasFnAttribute(Attribute::NoInline) || CS.isNoInline())
- return llvm::InlineCost::getNever();
-
- DEBUG(llvm::dbgs() << " Analyzing call of " << Callee->getName()
- << "...\n");
-
- CallAnalyzer CA(TTIWP->getTTI(*Callee), ACT, *Callee, Threshold, CS);
- bool ShouldInline = CA.analyzeCall(CS);
-
- DEBUG(CA.dump());
-
- // Check if there was a reason to force inlining or no inlining.
- if (!ShouldInline && CA.getCost() < CA.getThreshold())
- return InlineCost::getNever();
- if (ShouldInline && CA.getCost() >= CA.getThreshold())
- return InlineCost::getAlways();
-
- return llvm::InlineCost::get(CA.getCost(), CA.getThreshold());
-}
-
-bool InlineCostAnalysis::isInlineViable(Function &F) {
- bool ReturnsTwice = F.hasFnAttribute(Attribute::ReturnsTwice);
- for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
- // Disallow inlining of functions which contain indirect branches or
- // blockaddresses.
- if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
- return false;
-
- for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
- ++II) {
- CallSite CS(II);
- if (!CS)
- continue;
-
- // Disallow recursive calls.
- if (&F == CS.getCalledFunction())
- return false;
-
- // Disallow calls which expose returns-twice to a function not previously
- // attributed as such.
- if (!ReturnsTwice && CS.isCall() &&
- cast<CallInst>(CS.getInstruction())->canReturnTwice())
- return false;
-
- // Disallow inlining functions that call @llvm.localescape. Doing this
- // correctly would require major changes to the inliner.
- if (CS.getCalledFunction() &&
- CS.getCalledFunction()->getIntrinsicID() ==
- llvm::Intrinsic::localescape)
- return false;
- }
- }
-
- return true;
-}
+++ /dev/null
-;===- ./lib/Analysis/IPA/LLVMBuild.txt -------------------------*- Conf -*--===;
-;
-; The LLVM Compiler Infrastructure
-;
-; This file is distributed under the University of Illinois Open Source
-; License. See LICENSE.TXT for details.
-;
-;===------------------------------------------------------------------------===;
-;
-; This is an LLVMBuild description file for the components in this subdirectory.
-;
-; For more information on the LLVMBuild system, please see:
-;
-; http://llvm.org/docs/LLVMBuild.html
-;
-;===------------------------------------------------------------------------===;
-
-[component_0]
-type = Library
-name = IPA
-parent = Libraries
-library_name = ipa
-required_libraries = Analysis Core Support
+++ /dev/null
-##===- lib/Analysis/IPA/Makefile ---------------------------*- Makefile -*-===##
-#
-# The LLVM Compiler Infrastructure
-#
-# This file is distributed under the University of Illinois Open Source
-# License. See LICENSE.TXT for details.
-#
-##===----------------------------------------------------------------------===##
-
-LEVEL = ../../..
-LIBRARYNAME = LLVMipa
-BUILD_ARCHIVE = 1
-
-include $(LEVEL)/Makefile.common
-
--- /dev/null
+//===- InlineCost.cpp - Cost analysis for inliner -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements inline cost analysis.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CallingConv.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
+#include "llvm/IR/GlobalAlias.h"
+#include "llvm/IR/InstVisitor.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Operator.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "inline-cost"
+
+STATISTIC(NumCallsAnalyzed, "Number of call sites analyzed");
+
+namespace {
+
+class CallAnalyzer : public InstVisitor<CallAnalyzer, bool> {
+ typedef InstVisitor<CallAnalyzer, bool> Base;
+ friend class InstVisitor<CallAnalyzer, bool>;
+
+ /// The TargetTransformInfo available for this compilation.
+ const TargetTransformInfo &TTI;
+
+ /// The cache of @llvm.assume intrinsics.
+ AssumptionCacheTracker *ACT;
+
+ // The called function.
+ Function &F;
+
+ // The candidate callsite being analyzed. Please do not use this to do
+ // analysis in the caller function; we want the inline cost query to be
+ // easily cacheable. Instead, use the cover function paramHasAttr.
+ CallSite CandidateCS;
+
+ int Threshold;
+ int Cost;
+
+ bool IsCallerRecursive;
+ bool IsRecursiveCall;
+ bool ExposesReturnsTwice;
+ bool HasDynamicAlloca;
+ bool ContainsNoDuplicateCall;
+ bool HasReturn;
+ bool HasIndirectBr;
+ bool HasFrameEscape;
+
+ /// Number of bytes allocated statically by the callee.
+ uint64_t AllocatedSize;
+ unsigned NumInstructions, NumVectorInstructions;
+ int FiftyPercentVectorBonus, TenPercentVectorBonus;
+ int VectorBonus;
+
+ // While we walk the potentially-inlined instructions, we build up and
+ // maintain a mapping of simplified values specific to this callsite. The
+ // idea is to propagate any special information we have about arguments to
+ // this call through the inlinable section of the function, and account for
+ // likely simplifications post-inlining. The most important aspect we track
+ // is CFG altering simplifications -- when we prove a basic block dead, that
+ // can cause dramatic shifts in the cost of inlining a function.
+ DenseMap<Value *, Constant *> SimplifiedValues;
+
+ // Keep track of the values which map back (through function arguments) to
+ // allocas on the caller stack which could be simplified through SROA.
+ DenseMap<Value *, Value *> SROAArgValues;
+
+ // The mapping of caller Alloca values to their accumulated cost savings. If
+ // we have to disable SROA for one of the allocas, this tells us how much
+ // cost must be added.
+ DenseMap<Value *, int> SROAArgCosts;
+
+ // Keep track of values which map to a pointer base and constant offset.
+ DenseMap<Value *, std::pair<Value *, APInt> > ConstantOffsetPtrs;
+
+ // Custom simplification helper routines.
+ bool isAllocaDerivedArg(Value *V);
+ bool lookupSROAArgAndCost(Value *V, Value *&Arg,
+ DenseMap<Value *, int>::iterator &CostIt);
+ void disableSROA(DenseMap<Value *, int>::iterator CostIt);
+ void disableSROA(Value *V);
+ void accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+ int InstructionCost);
+ bool isGEPOffsetConstant(GetElementPtrInst &GEP);
+ bool accumulateGEPOffset(GEPOperator &GEP, APInt &Offset);
+ bool simplifyCallSite(Function *F, CallSite CS);
+ ConstantInt *stripAndComputeInBoundsConstantOffsets(Value *&V);
+
+ /// Return true if the given argument to the function being considered for
+ /// inlining has the given attribute set either at the call site or the
+ /// function declaration. Primarily used to inspect call site specific
+ /// attributes since these can be more precise than the ones on the callee
+ /// itself.
+ bool paramHasAttr(Argument *A, Attribute::AttrKind Attr);
+
+ /// Return true if the given value is known non null within the callee if
+ /// inlined through this particular callsite.
+ bool isKnownNonNullInCallee(Value *V);
+
+ // Custom analysis routines.
+ bool analyzeBlock(BasicBlock *BB, SmallPtrSetImpl<const Value *> &EphValues);
+
+ // Disable several entry points to the visitor so we don't accidentally use
+ // them by declaring but not defining them here.
+ void visit(Module *); void visit(Module &);
+ void visit(Function *); void visit(Function &);
+ void visit(BasicBlock *); void visit(BasicBlock &);
+
+ // Provide base case for our instruction visit.
+ bool visitInstruction(Instruction &I);
+
+ // Our visit overrides.
+ bool visitAlloca(AllocaInst &I);
+ bool visitPHI(PHINode &I);
+ bool visitGetElementPtr(GetElementPtrInst &I);
+ bool visitBitCast(BitCastInst &I);
+ bool visitPtrToInt(PtrToIntInst &I);
+ bool visitIntToPtr(IntToPtrInst &I);
+ bool visitCastInst(CastInst &I);
+ bool visitUnaryInstruction(UnaryInstruction &I);
+ bool visitCmpInst(CmpInst &I);
+ bool visitSub(BinaryOperator &I);
+ bool visitBinaryOperator(BinaryOperator &I);
+ bool visitLoad(LoadInst &I);
+ bool visitStore(StoreInst &I);
+ bool visitExtractValue(ExtractValueInst &I);
+ bool visitInsertValue(InsertValueInst &I);
+ bool visitCallSite(CallSite CS);
+ bool visitReturnInst(ReturnInst &RI);
+ bool visitBranchInst(BranchInst &BI);
+ bool visitSwitchInst(SwitchInst &SI);
+ bool visitIndirectBrInst(IndirectBrInst &IBI);
+ bool visitResumeInst(ResumeInst &RI);
+ bool visitCleanupReturnInst(CleanupReturnInst &RI);
+ bool visitCatchReturnInst(CatchReturnInst &RI);
+ bool visitUnreachableInst(UnreachableInst &I);
+
+public:
+ CallAnalyzer(const TargetTransformInfo &TTI, AssumptionCacheTracker *ACT,
+ Function &Callee, int Threshold, CallSite CSArg)
+ : TTI(TTI), ACT(ACT), F(Callee), CandidateCS(CSArg), Threshold(Threshold),
+ Cost(0), IsCallerRecursive(false), IsRecursiveCall(false),
+ ExposesReturnsTwice(false), HasDynamicAlloca(false),
+ ContainsNoDuplicateCall(false), HasReturn(false), HasIndirectBr(false),
+ HasFrameEscape(false), AllocatedSize(0), NumInstructions(0),
+ NumVectorInstructions(0), FiftyPercentVectorBonus(0),
+ TenPercentVectorBonus(0), VectorBonus(0), NumConstantArgs(0),
+ NumConstantOffsetPtrArgs(0), NumAllocaArgs(0), NumConstantPtrCmps(0),
+ NumConstantPtrDiffs(0), NumInstructionsSimplified(0),
+ SROACostSavings(0), SROACostSavingsLost(0) {}
+
+ bool analyzeCall(CallSite CS);
+
+ int getThreshold() { return Threshold; }
+ int getCost() { return Cost; }
+
+ // Keep a bunch of stats about the cost savings found so we can print them
+ // out when debugging.
+ unsigned NumConstantArgs;
+ unsigned NumConstantOffsetPtrArgs;
+ unsigned NumAllocaArgs;
+ unsigned NumConstantPtrCmps;
+ unsigned NumConstantPtrDiffs;
+ unsigned NumInstructionsSimplified;
+ unsigned SROACostSavings;
+ unsigned SROACostSavingsLost;
+
+ void dump();
+};
+
+} // namespace
+
+/// \brief Test whether the given value is an Alloca-derived function argument.
+bool CallAnalyzer::isAllocaDerivedArg(Value *V) {
+ return SROAArgValues.count(V);
+}
+
+/// \brief Lookup the SROA-candidate argument and cost iterator which V maps to.
+/// Returns false if V does not map to a SROA-candidate.
+bool CallAnalyzer::lookupSROAArgAndCost(
+ Value *V, Value *&Arg, DenseMap<Value *, int>::iterator &CostIt) {
+ if (SROAArgValues.empty() || SROAArgCosts.empty())
+ return false;
+
+ DenseMap<Value *, Value *>::iterator ArgIt = SROAArgValues.find(V);
+ if (ArgIt == SROAArgValues.end())
+ return false;
+
+ Arg = ArgIt->second;
+ CostIt = SROAArgCosts.find(Arg);
+ return CostIt != SROAArgCosts.end();
+}
+
+/// \brief Disable SROA for the candidate marked by this cost iterator.
+///
+/// This marks the candidate as no longer viable for SROA, and adds the cost
+/// savings associated with it back into the inline cost measurement.
+void CallAnalyzer::disableSROA(DenseMap<Value *, int>::iterator CostIt) {
+ // If we're no longer able to perform SROA we need to undo its cost savings
+ // and prevent subsequent analysis.
+ Cost += CostIt->second;
+ SROACostSavings -= CostIt->second;
+ SROACostSavingsLost += CostIt->second;
+ SROAArgCosts.erase(CostIt);
+}
+
+/// \brief If 'V' maps to a SROA candidate, disable SROA for it.
+void CallAnalyzer::disableSROA(Value *V) {
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(V, SROAArg, CostIt))
+ disableSROA(CostIt);
+}
+
+/// \brief Accumulate the given cost for a particular SROA candidate.
+void CallAnalyzer::accumulateSROACost(DenseMap<Value *, int>::iterator CostIt,
+ int InstructionCost) {
+ CostIt->second += InstructionCost;
+ SROACostSavings += InstructionCost;
+}
+
+/// \brief Check whether a GEP's indices are all constant.
+///
+/// Respects any simplified values known during the analysis of this callsite.
+bool CallAnalyzer::isGEPOffsetConstant(GetElementPtrInst &GEP) {
+ for (User::op_iterator I = GEP.idx_begin(), E = GEP.idx_end(); I != E; ++I)
+ if (!isa<Constant>(*I) && !SimplifiedValues.lookup(*I))
+ return false;
+
+ return true;
+}
+
+/// \brief Accumulate a constant GEP offset into an APInt if possible.
+///
+/// Returns false if unable to compute the offset for any reason. Respects any
+/// simplified values known during the analysis of this callsite.
+bool CallAnalyzer::accumulateGEPOffset(GEPOperator &GEP, APInt &Offset) {
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ unsigned IntPtrWidth = DL.getPointerSizeInBits();
+ assert(IntPtrWidth == Offset.getBitWidth());
+
+ for (gep_type_iterator GTI = gep_type_begin(GEP), GTE = gep_type_end(GEP);
+ GTI != GTE; ++GTI) {
+ ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
+ if (!OpC)
+ if (Constant *SimpleOp = SimplifiedValues.lookup(GTI.getOperand()))
+ OpC = dyn_cast<ConstantInt>(SimpleOp);
+ if (!OpC)
+ return false;
+ if (OpC->isZero()) continue;
+
+ // Handle a struct index, which adds its field offset to the pointer.
+ if (StructType *STy = dyn_cast<StructType>(*GTI)) {
+ unsigned ElementIdx = OpC->getZExtValue();
+ const StructLayout *SL = DL.getStructLayout(STy);
+ Offset += APInt(IntPtrWidth, SL->getElementOffset(ElementIdx));
+ continue;
+ }
+
+ APInt TypeSize(IntPtrWidth, DL.getTypeAllocSize(GTI.getIndexedType()));
+ Offset += OpC->getValue().sextOrTrunc(IntPtrWidth) * TypeSize;
+ }
+ return true;
+}
+
+bool CallAnalyzer::visitAlloca(AllocaInst &I) {
+ // Check whether inlining will turn a dynamic alloca into a static
+ // alloca, and handle that case.
+ if (I.isArrayAllocation()) {
+ if (Constant *Size = SimplifiedValues.lookup(I.getArraySize())) {
+ ConstantInt *AllocSize = dyn_cast<ConstantInt>(Size);
+ assert(AllocSize && "Allocation size not a constant int?");
+ Type *Ty = I.getAllocatedType();
+ AllocatedSize += Ty->getPrimitiveSizeInBits() * AllocSize->getZExtValue();
+ return Base::visitAlloca(I);
+ }
+ }
+
+ // Accumulate the allocated size.
+ if (I.isStaticAlloca()) {
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ Type *Ty = I.getAllocatedType();
+ AllocatedSize += DL.getTypeAllocSize(Ty);
+ }
+
+ // We will happily inline static alloca instructions.
+ if (I.isStaticAlloca())
+ return Base::visitAlloca(I);
+
+ // FIXME: This is overly conservative. Dynamic allocas are inefficient for
+ // a variety of reasons, and so we would like to not inline them into
+ // functions which don't currently have a dynamic alloca. This simply
+ // disables inlining altogether in the presence of a dynamic alloca.
+ HasDynamicAlloca = true;
+ return false;
+}
+
+bool CallAnalyzer::visitPHI(PHINode &I) {
+ // FIXME: We should potentially be tracking values through phi nodes,
+ // especially when they collapse to a single value due to deleted CFG edges
+ // during inlining.
+
+ // FIXME: We need to propagate SROA *disabling* through phi nodes, even
+ // though we don't want to propagate it's bonuses. The idea is to disable
+ // SROA if it *might* be used in an inappropriate manner.
+
+ // Phi nodes are always zero-cost.
+ return true;
+}
+
+bool CallAnalyzer::visitGetElementPtr(GetElementPtrInst &I) {
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ bool SROACandidate = lookupSROAArgAndCost(I.getPointerOperand(),
+ SROAArg, CostIt);
+
+ // Try to fold GEPs of constant-offset call site argument pointers. This
+ // requires target data and inbounds GEPs.
+ if (I.isInBounds()) {
+ // Check if we have a base + offset for the pointer.
+ Value *Ptr = I.getPointerOperand();
+ std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Ptr);
+ if (BaseAndOffset.first) {
+ // Check if the offset of this GEP is constant, and if so accumulate it
+ // into Offset.
+ if (!accumulateGEPOffset(cast<GEPOperator>(I), BaseAndOffset.second)) {
+ // Non-constant GEPs aren't folded, and disable SROA.
+ if (SROACandidate)
+ disableSROA(CostIt);
+ return false;
+ }
+
+ // Add the result as a new mapping to Base + Offset.
+ ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+ // Also handle SROA candidates here, we already know that the GEP is
+ // all-constant indexed.
+ if (SROACandidate)
+ SROAArgValues[&I] = SROAArg;
+
+ return true;
+ }
+ }
+
+ if (isGEPOffsetConstant(I)) {
+ if (SROACandidate)
+ SROAArgValues[&I] = SROAArg;
+
+ // Constant GEPs are modeled as free.
+ return true;
+ }
+
+ // Variable GEPs will require math and will disable SROA.
+ if (SROACandidate)
+ disableSROA(CostIt);
+ return false;
+}
+
+bool CallAnalyzer::visitBitCast(BitCastInst &I) {
+ // Propagate constants through bitcasts.
+ Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+ if (!COp)
+ COp = SimplifiedValues.lookup(I.getOperand(0));
+ if (COp)
+ if (Constant *C = ConstantExpr::getBitCast(COp, I.getType())) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+
+ // Track base/offsets through casts
+ std::pair<Value *, APInt> BaseAndOffset
+ = ConstantOffsetPtrs.lookup(I.getOperand(0));
+ // Casts don't change the offset, just wrap it up.
+ if (BaseAndOffset.first)
+ ConstantOffsetPtrs[&I] = BaseAndOffset;
+
+ // Also look for SROA candidates here.
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+ SROAArgValues[&I] = SROAArg;
+
+ // Bitcasts are always zero cost.
+ return true;
+}
+
+bool CallAnalyzer::visitPtrToInt(PtrToIntInst &I) {
+ // Propagate constants through ptrtoint.
+ Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+ if (!COp)
+ COp = SimplifiedValues.lookup(I.getOperand(0));
+ if (COp)
+ if (Constant *C = ConstantExpr::getPtrToInt(COp, I.getType())) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+
+ // Track base/offset pairs when converted to a plain integer provided the
+ // integer is large enough to represent the pointer.
+ unsigned IntegerSize = I.getType()->getScalarSizeInBits();
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ if (IntegerSize >= DL.getPointerSizeInBits()) {
+ std::pair<Value *, APInt> BaseAndOffset
+ = ConstantOffsetPtrs.lookup(I.getOperand(0));
+ if (BaseAndOffset.first)
+ ConstantOffsetPtrs[&I] = BaseAndOffset;
+ }
+
+ // This is really weird. Technically, ptrtoint will disable SROA. However,
+ // unless that ptrtoint is *used* somewhere in the live basic blocks after
+ // inlining, it will be nuked, and SROA should proceed. All of the uses which
+ // would block SROA would also block SROA if applied directly to a pointer,
+ // and so we can just add the integer in here. The only places where SROA is
+ // preserved either cannot fire on an integer, or won't in-and-of themselves
+ // disable SROA (ext) w/o some later use that we would see and disable.
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt))
+ SROAArgValues[&I] = SROAArg;
+
+ return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitIntToPtr(IntToPtrInst &I) {
+ // Propagate constants through ptrtoint.
+ Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+ if (!COp)
+ COp = SimplifiedValues.lookup(I.getOperand(0));
+ if (COp)
+ if (Constant *C = ConstantExpr::getIntToPtr(COp, I.getType())) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+
+ // Track base/offset pairs when round-tripped through a pointer without
+ // modifications provided the integer is not too large.
+ Value *Op = I.getOperand(0);
+ unsigned IntegerSize = Op->getType()->getScalarSizeInBits();
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ if (IntegerSize <= DL.getPointerSizeInBits()) {
+ std::pair<Value *, APInt> BaseAndOffset = ConstantOffsetPtrs.lookup(Op);
+ if (BaseAndOffset.first)
+ ConstantOffsetPtrs[&I] = BaseAndOffset;
+ }
+
+ // "Propagate" SROA here in the same manner as we do for ptrtoint above.
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(Op, SROAArg, CostIt))
+ SROAArgValues[&I] = SROAArg;
+
+ return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitCastInst(CastInst &I) {
+ // Propagate constants through ptrtoint.
+ Constant *COp = dyn_cast<Constant>(I.getOperand(0));
+ if (!COp)
+ COp = SimplifiedValues.lookup(I.getOperand(0));
+ if (COp)
+ if (Constant *C = ConstantExpr::getCast(I.getOpcode(), COp, I.getType())) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+
+ // Disable SROA in the face of arbitrary casts we don't whitelist elsewhere.
+ disableSROA(I.getOperand(0));
+
+ return TargetTransformInfo::TCC_Free == TTI.getUserCost(&I);
+}
+
+bool CallAnalyzer::visitUnaryInstruction(UnaryInstruction &I) {
+ Value *Operand = I.getOperand(0);
+ Constant *COp = dyn_cast<Constant>(Operand);
+ if (!COp)
+ COp = SimplifiedValues.lookup(Operand);
+ if (COp) {
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ if (Constant *C = ConstantFoldInstOperands(I.getOpcode(), I.getType(),
+ COp, DL)) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+ }
+
+ // Disable any SROA on the argument to arbitrary unary operators.
+ disableSROA(Operand);
+
+ return false;
+}
+
+bool CallAnalyzer::paramHasAttr(Argument *A, Attribute::AttrKind Attr) {
+ unsigned ArgNo = A->getArgNo();
+ return CandidateCS.paramHasAttr(ArgNo+1, Attr);
+}
+
+bool CallAnalyzer::isKnownNonNullInCallee(Value *V) {
+ // Does the *call site* have the NonNull attribute set on an argument? We
+ // use the attribute on the call site to memoize any analysis done in the
+ // caller. This will also trip if the callee function has a non-null
+ // parameter attribute, but that's a less interesting case because hopefully
+ // the callee would already have been simplified based on that.
+ if (Argument *A = dyn_cast<Argument>(V))
+ if (paramHasAttr(A, Attribute::NonNull))
+ return true;
+
+ // Is this an alloca in the caller? This is distinct from the attribute case
+ // above because attributes aren't updated within the inliner itself and we
+ // always want to catch the alloca derived case.
+ if (isAllocaDerivedArg(V))
+ // We can actually predict the result of comparisons between an
+ // alloca-derived value and null. Note that this fires regardless of
+ // SROA firing.
+ return true;
+
+ return false;
+}
+
+bool CallAnalyzer::visitCmpInst(CmpInst &I) {
+ Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+ // First try to handle simplified comparisons.
+ if (!isa<Constant>(LHS))
+ if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+ LHS = SimpleLHS;
+ if (!isa<Constant>(RHS))
+ if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+ RHS = SimpleRHS;
+ if (Constant *CLHS = dyn_cast<Constant>(LHS)) {
+ if (Constant *CRHS = dyn_cast<Constant>(RHS))
+ if (Constant *C = ConstantExpr::getCompare(I.getPredicate(), CLHS, CRHS)) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+ }
+
+ if (I.getOpcode() == Instruction::FCmp)
+ return false;
+
+ // Otherwise look for a comparison between constant offset pointers with
+ // a common base.
+ Value *LHSBase, *RHSBase;
+ APInt LHSOffset, RHSOffset;
+ std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+ if (LHSBase) {
+ std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+ if (RHSBase && LHSBase == RHSBase) {
+ // We have common bases, fold the icmp to a constant based on the
+ // offsets.
+ Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+ Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+ if (Constant *C = ConstantExpr::getICmp(I.getPredicate(), CLHS, CRHS)) {
+ SimplifiedValues[&I] = C;
+ ++NumConstantPtrCmps;
+ return true;
+ }
+ }
+ }
+
+ // If the comparison is an equality comparison with null, we can simplify it
+ // if we know the value (argument) can't be null
+ if (I.isEquality() && isa<ConstantPointerNull>(I.getOperand(1)) &&
+ isKnownNonNullInCallee(I.getOperand(0))) {
+ bool IsNotEqual = I.getPredicate() == CmpInst::ICMP_NE;
+ SimplifiedValues[&I] = IsNotEqual ? ConstantInt::getTrue(I.getType())
+ : ConstantInt::getFalse(I.getType());
+ return true;
+ }
+ // Finally check for SROA candidates in comparisons.
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(I.getOperand(0), SROAArg, CostIt)) {
+ if (isa<ConstantPointerNull>(I.getOperand(1))) {
+ accumulateSROACost(CostIt, InlineConstants::InstrCost);
+ return true;
+ }
+
+ disableSROA(CostIt);
+ }
+
+ return false;
+}
+
+bool CallAnalyzer::visitSub(BinaryOperator &I) {
+ // Try to handle a special case: we can fold computing the difference of two
+ // constant-related pointers.
+ Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+ Value *LHSBase, *RHSBase;
+ APInt LHSOffset, RHSOffset;
+ std::tie(LHSBase, LHSOffset) = ConstantOffsetPtrs.lookup(LHS);
+ if (LHSBase) {
+ std::tie(RHSBase, RHSOffset) = ConstantOffsetPtrs.lookup(RHS);
+ if (RHSBase && LHSBase == RHSBase) {
+ // We have common bases, fold the subtract to a constant based on the
+ // offsets.
+ Constant *CLHS = ConstantInt::get(LHS->getContext(), LHSOffset);
+ Constant *CRHS = ConstantInt::get(RHS->getContext(), RHSOffset);
+ if (Constant *C = ConstantExpr::getSub(CLHS, CRHS)) {
+ SimplifiedValues[&I] = C;
+ ++NumConstantPtrDiffs;
+ return true;
+ }
+ }
+ }
+
+ // Otherwise, fall back to the generic logic for simplifying and handling
+ // instructions.
+ return Base::visitSub(I);
+}
+
+bool CallAnalyzer::visitBinaryOperator(BinaryOperator &I) {
+ Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ if (!isa<Constant>(LHS))
+ if (Constant *SimpleLHS = SimplifiedValues.lookup(LHS))
+ LHS = SimpleLHS;
+ if (!isa<Constant>(RHS))
+ if (Constant *SimpleRHS = SimplifiedValues.lookup(RHS))
+ RHS = SimpleRHS;
+ Value *SimpleV = nullptr;
+ if (auto FI = dyn_cast<FPMathOperator>(&I))
+ SimpleV =
+ SimplifyFPBinOp(I.getOpcode(), LHS, RHS, FI->getFastMathFlags(), DL);
+ else
+ SimpleV = SimplifyBinOp(I.getOpcode(), LHS, RHS, DL);
+
+ if (Constant *C = dyn_cast_or_null<Constant>(SimpleV)) {
+ SimplifiedValues[&I] = C;
+ return true;
+ }
+
+ // Disable any SROA on arguments to arbitrary, unsimplified binary operators.
+ disableSROA(LHS);
+ disableSROA(RHS);
+
+ return false;
+}
+
+bool CallAnalyzer::visitLoad(LoadInst &I) {
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
+ if (I.isSimple()) {
+ accumulateSROACost(CostIt, InlineConstants::InstrCost);
+ return true;
+ }
+
+ disableSROA(CostIt);
+ }
+
+ return false;
+}
+
+bool CallAnalyzer::visitStore(StoreInst &I) {
+ Value *SROAArg;
+ DenseMap<Value *, int>::iterator CostIt;
+ if (lookupSROAArgAndCost(I.getPointerOperand(), SROAArg, CostIt)) {
+ if (I.isSimple()) {
+ accumulateSROACost(CostIt, InlineConstants::InstrCost);
+ return true;
+ }
+
+ disableSROA(CostIt);
+ }
+
+ return false;
+}
+
+bool CallAnalyzer::visitExtractValue(ExtractValueInst &I) {
+ // Constant folding for extract value is trivial.
+ Constant *C = dyn_cast<Constant>(I.getAggregateOperand());
+ if (!C)
+ C = SimplifiedValues.lookup(I.getAggregateOperand());
+ if (C) {
+ SimplifiedValues[&I] = ConstantExpr::getExtractValue(C, I.getIndices());
+ return true;
+ }
+
+ // SROA can look through these but give them a cost.
+ return false;
+}
+
+bool CallAnalyzer::visitInsertValue(InsertValueInst &I) {
+ // Constant folding for insert value is trivial.
+ Constant *AggC = dyn_cast<Constant>(I.getAggregateOperand());
+ if (!AggC)
+ AggC = SimplifiedValues.lookup(I.getAggregateOperand());
+ Constant *InsertedC = dyn_cast<Constant>(I.getInsertedValueOperand());
+ if (!InsertedC)
+ InsertedC = SimplifiedValues.lookup(I.getInsertedValueOperand());
+ if (AggC && InsertedC) {
+ SimplifiedValues[&I] = ConstantExpr::getInsertValue(AggC, InsertedC,
+ I.getIndices());
+ return true;
+ }
+
+ // SROA can look through these but give them a cost.
+ return false;
+}
+
+/// \brief Try to simplify a call site.
+///
+/// Takes a concrete function and callsite and tries to actually simplify it by
+/// analyzing the arguments and call itself with instsimplify. Returns true if
+/// it has simplified the callsite to some other entity (a constant), making it
+/// free.
+bool CallAnalyzer::simplifyCallSite(Function *F, CallSite CS) {
+ // FIXME: Using the instsimplify logic directly for this is inefficient
+ // because we have to continually rebuild the argument list even when no
+ // simplifications can be performed. Until that is fixed with remapping
+ // inside of instsimplify, directly constant fold calls here.
+ if (!canConstantFoldCallTo(F))
+ return false;
+
+ // Try to re-map the arguments to constants.
+ SmallVector<Constant *, 4> ConstantArgs;
+ ConstantArgs.reserve(CS.arg_size());
+ for (CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
+ I != E; ++I) {
+ Constant *C = dyn_cast<Constant>(*I);
+ if (!C)
+ C = dyn_cast_or_null<Constant>(SimplifiedValues.lookup(*I));
+ if (!C)
+ return false; // This argument doesn't map to a constant.
+
+ ConstantArgs.push_back(C);
+ }
+ if (Constant *C = ConstantFoldCall(F, ConstantArgs)) {
+ SimplifiedValues[CS.getInstruction()] = C;
+ return true;
+ }
+
+ return false;
+}
+
+bool CallAnalyzer::visitCallSite(CallSite CS) {
+ if (CS.hasFnAttr(Attribute::ReturnsTwice) &&
+ !F.hasFnAttribute(Attribute::ReturnsTwice)) {
+ // This aborts the entire analysis.
+ ExposesReturnsTwice = true;
+ return false;
+ }
+ if (CS.isCall() &&
+ cast<CallInst>(CS.getInstruction())->cannotDuplicate())
+ ContainsNoDuplicateCall = true;
+
+ if (Function *F = CS.getCalledFunction()) {
+ // When we have a concrete function, first try to simplify it directly.
+ if (simplifyCallSite(F, CS))
+ return true;
+
+ // Next check if it is an intrinsic we know about.
+ // FIXME: Lift this into part of the InstVisitor.
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CS.getInstruction())) {
+ switch (II->getIntrinsicID()) {
+ default:
+ return Base::visitCallSite(CS);
+
+ case Intrinsic::memset:
+ case Intrinsic::memcpy:
+ case Intrinsic::memmove:
+ // SROA can usually chew through these intrinsics, but they aren't free.
+ return false;
+ case Intrinsic::localescape:
+ HasFrameEscape = true;
+ return false;
+ }
+ }
+
+ if (F == CS.getInstruction()->getParent()->getParent()) {
+ // This flag will fully abort the analysis, so don't bother with anything
+ // else.
+ IsRecursiveCall = true;
+ return false;
+ }
+
+ if (TTI.isLoweredToCall(F)) {
+ // We account for the average 1 instruction per call argument setup
+ // here.
+ Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+ // Everything other than inline ASM will also have a significant cost
+ // merely from making the call.
+ if (!isa<InlineAsm>(CS.getCalledValue()))
+ Cost += InlineConstants::CallPenalty;
+ }
+
+ return Base::visitCallSite(CS);
+ }
+
+ // Otherwise we're in a very special case -- an indirect function call. See
+ // if we can be particularly clever about this.
+ Value *Callee = CS.getCalledValue();
+
+ // First, pay the price of the argument setup. We account for the average
+ // 1 instruction per call argument setup here.
+ Cost += CS.arg_size() * InlineConstants::InstrCost;
+
+ // Next, check if this happens to be an indirect function call to a known
+ // function in this inline context. If not, we've done all we can.
+ Function *F = dyn_cast_or_null<Function>(SimplifiedValues.lookup(Callee));
+ if (!F)
+ return Base::visitCallSite(CS);
+
+ // If we have a constant that we are calling as a function, we can peer
+ // through it and see the function target. This happens not infrequently
+ // during devirtualization and so we want to give it a hefty bonus for
+ // inlining, but cap that bonus in the event that inlining wouldn't pan
+ // out. Pretend to inline the function, with a custom threshold.
+ CallAnalyzer CA(TTI, ACT, *F, InlineConstants::IndirectCallThreshold, CS);
+ if (CA.analyzeCall(CS)) {
+ // We were able to inline the indirect call! Subtract the cost from the
+ // bonus we want to apply, but don't go below zero.
+ Cost -= std::max(0, InlineConstants::IndirectCallThreshold - CA.getCost());
+ }
+
+ return Base::visitCallSite(CS);
+}
+
+bool CallAnalyzer::visitReturnInst(ReturnInst &RI) {
+ // At least one return instruction will be free after inlining.
+ bool Free = !HasReturn;
+ HasReturn = true;
+ return Free;
+}
+
+bool CallAnalyzer::visitBranchInst(BranchInst &BI) {
+ // We model unconditional branches as essentially free -- they really
+ // shouldn't exist at all, but handling them makes the behavior of the
+ // inliner more regular and predictable. Interestingly, conditional branches
+ // which will fold away are also free.
+ return BI.isUnconditional() || isa<ConstantInt>(BI.getCondition()) ||
+ dyn_cast_or_null<ConstantInt>(
+ SimplifiedValues.lookup(BI.getCondition()));
+}
+
+bool CallAnalyzer::visitSwitchInst(SwitchInst &SI) {
+ // We model unconditional switches as free, see the comments on handling
+ // branches.
+ if (isa<ConstantInt>(SI.getCondition()))
+ return true;
+ if (Value *V = SimplifiedValues.lookup(SI.getCondition()))
+ if (isa<ConstantInt>(V))
+ return true;
+
+ // Otherwise, we need to accumulate a cost proportional to the number of
+ // distinct successor blocks. This fan-out in the CFG cannot be represented
+ // for free even if we can represent the core switch as a jumptable that
+ // takes a single instruction.
+ //
+ // NB: We convert large switches which are just used to initialize large phi
+ // nodes to lookup tables instead in simplify-cfg, so this shouldn't prevent
+ // inlining those. It will prevent inlining in cases where the optimization
+ // does not (yet) fire.
+ SmallPtrSet<BasicBlock *, 8> SuccessorBlocks;
+ SuccessorBlocks.insert(SI.getDefaultDest());
+ for (auto I = SI.case_begin(), E = SI.case_end(); I != E; ++I)
+ SuccessorBlocks.insert(I.getCaseSuccessor());
+ // Add cost corresponding to the number of distinct destinations. The first
+ // we model as free because of fallthrough.
+ Cost += (SuccessorBlocks.size() - 1) * InlineConstants::InstrCost;
+ return false;
+}
+
+bool CallAnalyzer::visitIndirectBrInst(IndirectBrInst &IBI) {
+ // We never want to inline functions that contain an indirectbr. This is
+ // incorrect because all the blockaddress's (in static global initializers
+ // for example) would be referring to the original function, and this
+ // indirect jump would jump from the inlined copy of the function into the
+ // original function which is extremely undefined behavior.
+ // FIXME: This logic isn't really right; we can safely inline functions with
+ // indirectbr's as long as no other function or global references the
+ // blockaddress of a block within the current function.
+ HasIndirectBr = true;
+ return false;
+}
+
+bool CallAnalyzer::visitResumeInst(ResumeInst &RI) {
+ // FIXME: It's not clear that a single instruction is an accurate model for
+ // the inline cost of a resume instruction.
+ return false;
+}
+
+bool CallAnalyzer::visitCleanupReturnInst(CleanupReturnInst &CRI) {
+ // FIXME: It's not clear that a single instruction is an accurate model for
+ // the inline cost of a cleanupret instruction.
+ return false;
+}
+
+bool CallAnalyzer::visitCatchReturnInst(CatchReturnInst &CRI) {
+ // FIXME: It's not clear that a single instruction is an accurate model for
+ // the inline cost of a cleanupret instruction.
+ return false;
+}
+
+bool CallAnalyzer::visitUnreachableInst(UnreachableInst &I) {
+ // FIXME: It might be reasonably to discount the cost of instructions leading
+ // to unreachable as they have the lowest possible impact on both runtime and
+ // code size.
+ return true; // No actual code is needed for unreachable.
+}
+
+bool CallAnalyzer::visitInstruction(Instruction &I) {
+ // Some instructions are free. All of the free intrinsics can also be
+ // handled by SROA, etc.
+ if (TargetTransformInfo::TCC_Free == TTI.getUserCost(&I))
+ return true;
+
+ // We found something we don't understand or can't handle. Mark any SROA-able
+ // values in the operand list as no longer viable.
+ for (User::op_iterator OI = I.op_begin(), OE = I.op_end(); OI != OE; ++OI)
+ disableSROA(*OI);
+
+ return false;
+}
+
+
+/// \brief Analyze a basic block for its contribution to the inline cost.
+///
+/// This method walks the analyzer over every instruction in the given basic
+/// block and accounts for their cost during inlining at this callsite. It
+/// aborts early if the threshold has been exceeded or an impossible to inline
+/// construct has been detected. It returns false if inlining is no longer
+/// viable, and true if inlining remains viable.
+bool CallAnalyzer::analyzeBlock(BasicBlock *BB,
+ SmallPtrSetImpl<const Value *> &EphValues) {
+ for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ // FIXME: Currently, the number of instructions in a function regardless of
+ // our ability to simplify them during inline to constants or dead code,
+ // are actually used by the vector bonus heuristic. As long as that's true,
+ // we have to special case debug intrinsics here to prevent differences in
+ // inlining due to debug symbols. Eventually, the number of unsimplified
+ // instructions shouldn't factor into the cost computation, but until then,
+ // hack around it here.
+ if (isa<DbgInfoIntrinsic>(I))
+ continue;
+
+ // Skip ephemeral values.
+ if (EphValues.count(I))
+ continue;
+
+ ++NumInstructions;
+ if (isa<ExtractElementInst>(I) || I->getType()->isVectorTy())
+ ++NumVectorInstructions;
+
+ // If the instruction is floating point, and the target says this operation is
+ // expensive or the function has the "use-soft-float" attribute, this may
+ // eventually become a library call. Treat the cost as such.
+ if (I->getType()->isFloatingPointTy()) {
+ bool hasSoftFloatAttr = false;
+
+ // If the function has the "use-soft-float" attribute, mark it as expensive.
+ if (F.hasFnAttribute("use-soft-float")) {
+ Attribute Attr = F.getFnAttribute("use-soft-float");
+ StringRef Val = Attr.getValueAsString();
+ if (Val == "true")
+ hasSoftFloatAttr = true;
+ }
+
+ if (TTI.getFPOpCost(I->getType()) == TargetTransformInfo::TCC_Expensive ||
+ hasSoftFloatAttr)
+ Cost += InlineConstants::CallPenalty;
+ }
+
+ // If the instruction simplified to a constant, there is no cost to this
+ // instruction. Visit the instructions using our InstVisitor to account for
+ // all of the per-instruction logic. The visit tree returns true if we
+ // consumed the instruction in any way, and false if the instruction's base
+ // cost should count against inlining.
+ if (Base::visit(I))
+ ++NumInstructionsSimplified;
+ else
+ Cost += InlineConstants::InstrCost;
+
+ // If the visit this instruction detected an uninlinable pattern, abort.
+ if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+ HasIndirectBr || HasFrameEscape)
+ return false;
+
+ // If the caller is a recursive function then we don't want to inline
+ // functions which allocate a lot of stack space because it would increase
+ // the caller stack usage dramatically.
+ if (IsCallerRecursive &&
+ AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+ return false;
+
+ // Check if we've past the maximum possible threshold so we don't spin in
+ // huge basic blocks that will never inline.
+ if (Cost > Threshold)
+ return false;
+ }
+
+ return true;
+}
+
+/// \brief Compute the base pointer and cumulative constant offsets for V.
+///
+/// This strips all constant offsets off of V, leaving it the base pointer, and
+/// accumulates the total constant offset applied in the returned constant. It
+/// returns 0 if V is not a pointer, and returns the constant '0' if there are
+/// no constant offsets applied.
+ConstantInt *CallAnalyzer::stripAndComputeInBoundsConstantOffsets(Value *&V) {
+ if (!V->getType()->isPointerTy())
+ return nullptr;
+
+ const DataLayout &DL = F.getParent()->getDataLayout();
+ unsigned IntPtrWidth = DL.getPointerSizeInBits();
+ APInt Offset = APInt::getNullValue(IntPtrWidth);
+
+ // Even though we don't look through PHI nodes, we could be called on an
+ // instruction in an unreachable block, which may be on a cycle.
+ SmallPtrSet<Value *, 4> Visited;
+ Visited.insert(V);
+ do {
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ if (!GEP->isInBounds() || !accumulateGEPOffset(*GEP, Offset))
+ return nullptr;
+ V = GEP->getPointerOperand();
+ } else if (Operator::getOpcode(V) == Instruction::BitCast) {
+ V = cast<Operator>(V)->getOperand(0);
+ } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) {
+ if (GA->mayBeOverridden())
+ break;
+ V = GA->getAliasee();
+ } else {
+ break;
+ }
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V).second);
+
+ Type *IntPtrTy = DL.getIntPtrType(V->getContext());
+ return cast<ConstantInt>(ConstantInt::get(IntPtrTy, Offset));
+}
+
+/// \brief Analyze a call site for potential inlining.
+///
+/// Returns true if inlining this call is viable, and false if it is not
+/// viable. It computes the cost and adjusts the threshold based on numerous
+/// factors and heuristics. If this method returns false but the computed cost
+/// is below the computed threshold, then inlining was forcibly disabled by
+/// some artifact of the routine.
+bool CallAnalyzer::analyzeCall(CallSite CS) {
+ ++NumCallsAnalyzed;
+
+ // Perform some tweaks to the cost and threshold based on the direct
+ // callsite information.
+
+ // We want to more aggressively inline vector-dense kernels, so up the
+ // threshold, and we'll lower it if the % of vector instructions gets too
+ // low. Note that these bonuses are some what arbitrary and evolved over time
+ // by accident as much as because they are principled bonuses.
+ //
+ // FIXME: It would be nice to remove all such bonuses. At least it would be
+ // nice to base the bonus values on something more scientific.
+ assert(NumInstructions == 0);
+ assert(NumVectorInstructions == 0);
+ FiftyPercentVectorBonus = 3 * Threshold / 2;
+ TenPercentVectorBonus = 3 * Threshold / 4;
+ const DataLayout &DL = F.getParent()->getDataLayout();
+
+ // Track whether the post-inlining function would have more than one basic
+ // block. A single basic block is often intended for inlining. Balloon the
+ // threshold by 50% until we pass the single-BB phase.
+ bool SingleBB = true;
+ int SingleBBBonus = Threshold / 2;
+
+ // Speculatively apply all possible bonuses to Threshold. If cost exceeds
+ // this Threshold any time, and cost cannot decrease, we can stop processing
+ // the rest of the function body.
+ Threshold += (SingleBBBonus + FiftyPercentVectorBonus);
+
+ // Give out bonuses per argument, as the instructions setting them up will
+ // be gone after inlining.
+ for (unsigned I = 0, E = CS.arg_size(); I != E; ++I) {
+ if (CS.isByValArgument(I)) {
+ // We approximate the number of loads and stores needed by dividing the
+ // size of the byval type by the target's pointer size.
+ PointerType *PTy = cast<PointerType>(CS.getArgument(I)->getType());
+ unsigned TypeSize = DL.getTypeSizeInBits(PTy->getElementType());
+ unsigned PointerSize = DL.getPointerSizeInBits();
+ // Ceiling division.
+ unsigned NumStores = (TypeSize + PointerSize - 1) / PointerSize;
+
+ // If it generates more than 8 stores it is likely to be expanded as an
+ // inline memcpy so we take that as an upper bound. Otherwise we assume
+ // one load and one store per word copied.
+ // FIXME: The maxStoresPerMemcpy setting from the target should be used
+ // here instead of a magic number of 8, but it's not available via
+ // DataLayout.
+ NumStores = std::min(NumStores, 8U);
+
+ Cost -= 2 * NumStores * InlineConstants::InstrCost;
+ } else {
+ // For non-byval arguments subtract off one instruction per call
+ // argument.
+ Cost -= InlineConstants::InstrCost;
+ }
+ }
+
+ // If there is only one call of the function, and it has internal linkage,
+ // the cost of inlining it drops dramatically.
+ bool OnlyOneCallAndLocalLinkage = F.hasLocalLinkage() && F.hasOneUse() &&
+ &F == CS.getCalledFunction();
+ if (OnlyOneCallAndLocalLinkage)
+ Cost += InlineConstants::LastCallToStaticBonus;
+
+ // If the instruction after the call, or if the normal destination of the
+ // invoke is an unreachable instruction, the function is noreturn. As such,
+ // there is little point in inlining this unless there is literally zero
+ // cost.
+ Instruction *Instr = CS.getInstruction();
+ if (InvokeInst *II = dyn_cast<InvokeInst>(Instr)) {
+ if (isa<UnreachableInst>(II->getNormalDest()->begin()))
+ Threshold = 0;
+ } else if (isa<UnreachableInst>(++BasicBlock::iterator(Instr)))
+ Threshold = 0;
+
+ // If this function uses the coldcc calling convention, prefer not to inline
+ // it.
+ if (F.getCallingConv() == CallingConv::Cold)
+ Cost += InlineConstants::ColdccPenalty;
+
+ // Check if we're done. This can happen due to bonuses and penalties.
+ if (Cost > Threshold)
+ return false;
+
+ if (F.empty())
+ return true;
+
+ Function *Caller = CS.getInstruction()->getParent()->getParent();
+ // Check if the caller function is recursive itself.
+ for (User *U : Caller->users()) {
+ CallSite Site(U);
+ if (!Site)
+ continue;
+ Instruction *I = Site.getInstruction();
+ if (I->getParent()->getParent() == Caller) {
+ IsCallerRecursive = true;
+ break;
+ }
+ }
+
+ // Populate our simplified values by mapping from function arguments to call
+ // arguments with known important simplifications.
+ CallSite::arg_iterator CAI = CS.arg_begin();
+ for (Function::arg_iterator FAI = F.arg_begin(), FAE = F.arg_end();
+ FAI != FAE; ++FAI, ++CAI) {
+ assert(CAI != CS.arg_end());
+ if (Constant *C = dyn_cast<Constant>(CAI))
+ SimplifiedValues[FAI] = C;
+
+ Value *PtrArg = *CAI;
+ if (ConstantInt *C = stripAndComputeInBoundsConstantOffsets(PtrArg)) {
+ ConstantOffsetPtrs[FAI] = std::make_pair(PtrArg, C->getValue());
+
+ // We can SROA any pointer arguments derived from alloca instructions.
+ if (isa<AllocaInst>(PtrArg)) {
+ SROAArgValues[FAI] = PtrArg;
+ SROAArgCosts[PtrArg] = 0;
+ }
+ }
+ }
+ NumConstantArgs = SimplifiedValues.size();
+ NumConstantOffsetPtrArgs = ConstantOffsetPtrs.size();
+ NumAllocaArgs = SROAArgValues.size();
+
+ // FIXME: If a caller has multiple calls to a callee, we end up recomputing
+ // the ephemeral values multiple times (and they're completely determined by
+ // the callee, so this is purely duplicate work).
+ SmallPtrSet<const Value *, 32> EphValues;
+ CodeMetrics::collectEphemeralValues(&F, &ACT->getAssumptionCache(F), EphValues);
+
+ // The worklist of live basic blocks in the callee *after* inlining. We avoid
+ // adding basic blocks of the callee which can be proven to be dead for this
+ // particular call site in order to get more accurate cost estimates. This
+ // requires a somewhat heavyweight iteration pattern: we need to walk the
+ // basic blocks in a breadth-first order as we insert live successors. To
+ // accomplish this, prioritizing for small iterations because we exit after
+ // crossing our threshold, we use a small-size optimized SetVector.
+ typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
+ SmallPtrSet<BasicBlock *, 16> > BBSetVector;
+ BBSetVector BBWorklist;
+ BBWorklist.insert(&F.getEntryBlock());
+ // Note that we *must not* cache the size, this loop grows the worklist.
+ for (unsigned Idx = 0; Idx != BBWorklist.size(); ++Idx) {
+ // Bail out the moment we cross the threshold. This means we'll under-count
+ // the cost, but only when undercounting doesn't matter.
+ if (Cost > Threshold)
+ break;
+
+ BasicBlock *BB = BBWorklist[Idx];
+ if (BB->empty())
+ continue;
+
+ // Disallow inlining a blockaddress. A blockaddress only has defined
+ // behavior for an indirect branch in the same function, and we do not
+ // currently support inlining indirect branches. But, the inliner may not
+ // see an indirect branch that ends up being dead code at a particular call
+ // site. If the blockaddress escapes the function, e.g., via a global
+ // variable, inlining may lead to an invalid cross-function reference.
+ if (BB->hasAddressTaken())
+ return false;
+
+ // Analyze the cost of this block. If we blow through the threshold, this
+ // returns false, and we can bail on out.
+ if (!analyzeBlock(BB, EphValues)) {
+ if (IsRecursiveCall || ExposesReturnsTwice || HasDynamicAlloca ||
+ HasIndirectBr || HasFrameEscape)
+ return false;
+
+ // If the caller is a recursive function then we don't want to inline
+ // functions which allocate a lot of stack space because it would increase
+ // the caller stack usage dramatically.
+ if (IsCallerRecursive &&
+ AllocatedSize > InlineConstants::TotalAllocaSizeRecursiveCaller)
+ return false;
+
+ break;
+ }
+
+ TerminatorInst *TI = BB->getTerminator();
+
+ // Add in the live successors by first checking whether we have terminator
+ // that may be simplified based on the values simplified by this call.
+ if (BranchInst *BI = dyn_cast<BranchInst>(TI)) {
+ if (BI->isConditional()) {
+ Value *Cond = BI->getCondition();
+ if (ConstantInt *SimpleCond
+ = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+ BBWorklist.insert(BI->getSuccessor(SimpleCond->isZero() ? 1 : 0));
+ continue;
+ }
+ }
+ } else if (SwitchInst *SI = dyn_cast<SwitchInst>(TI)) {
+ Value *Cond = SI->getCondition();
+ if (ConstantInt *SimpleCond
+ = dyn_cast_or_null<ConstantInt>(SimplifiedValues.lookup(Cond))) {
+ BBWorklist.insert(SI->findCaseValue(SimpleCond).getCaseSuccessor());
+ continue;
+ }
+ }
+
+ // If we're unable to select a particular successor, just count all of
+ // them.
+ for (unsigned TIdx = 0, TSize = TI->getNumSuccessors(); TIdx != TSize;
+ ++TIdx)
+ BBWorklist.insert(TI->getSuccessor(TIdx));
+
+ // If we had any successors at this point, than post-inlining is likely to
+ // have them as well. Note that we assume any basic blocks which existed
+ // due to branches or switches which folded above will also fold after
+ // inlining.
+ if (SingleBB && TI->getNumSuccessors() > 1) {
+ // Take off the bonus we applied to the threshold.
+ Threshold -= SingleBBBonus;
+ SingleBB = false;
+ }
+ }
+
+ // If this is a noduplicate call, we can still inline as long as
+ // inlining this would cause the removal of the caller (so the instruction
+ // is not actually duplicated, just moved).
+ if (!OnlyOneCallAndLocalLinkage && ContainsNoDuplicateCall)
+ return false;
+
+ // We applied the maximum possible vector bonus at the beginning. Now,
+ // subtract the excess bonus, if any, from the Threshold before
+ // comparing against Cost.
+ if (NumVectorInstructions <= NumInstructions / 10)
+ Threshold -= FiftyPercentVectorBonus;
+ else if (NumVectorInstructions <= NumInstructions / 2)
+ Threshold -= (FiftyPercentVectorBonus - TenPercentVectorBonus);
+
+ return Cost < Threshold;
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+/// \brief Dump stats about this call's analysis.
+void CallAnalyzer::dump() {
+#define DEBUG_PRINT_STAT(x) dbgs() << " " #x ": " << x << "\n"
+ DEBUG_PRINT_STAT(NumConstantArgs);
+ DEBUG_PRINT_STAT(NumConstantOffsetPtrArgs);
+ DEBUG_PRINT_STAT(NumAllocaArgs);
+ DEBUG_PRINT_STAT(NumConstantPtrCmps);
+ DEBUG_PRINT_STAT(NumConstantPtrDiffs);
+ DEBUG_PRINT_STAT(NumInstructionsSimplified);
+ DEBUG_PRINT_STAT(NumInstructions);
+ DEBUG_PRINT_STAT(SROACostSavings);
+ DEBUG_PRINT_STAT(SROACostSavingsLost);
+ DEBUG_PRINT_STAT(ContainsNoDuplicateCall);
+ DEBUG_PRINT_STAT(Cost);
+ DEBUG_PRINT_STAT(Threshold);
+#undef DEBUG_PRINT_STAT
+}
+#endif
+
+INITIALIZE_PASS_BEGIN(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+ true, true)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_END(InlineCostAnalysis, "inline-cost", "Inline Cost Analysis",
+ true, true)
+
+char InlineCostAnalysis::ID = 0;
+
+InlineCostAnalysis::InlineCostAnalysis() : CallGraphSCCPass(ID) {}
+
+InlineCostAnalysis::~InlineCostAnalysis() {}
+
+void InlineCostAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ AU.addRequired<AssumptionCacheTracker>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ CallGraphSCCPass::getAnalysisUsage(AU);
+}
+
+bool InlineCostAnalysis::runOnSCC(CallGraphSCC &SCC) {
+ TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
+ ACT = &getAnalysis<AssumptionCacheTracker>();
+ return false;
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, int Threshold) {
+ return getInlineCost(CS, CS.getCalledFunction(), Threshold);
+}
+
+/// \brief Test that two functions either have or have not the given attribute
+/// at the same time.
+template<typename AttrKind>
+static bool attributeMatches(Function *F1, Function *F2, AttrKind Attr) {
+ return F1->getFnAttribute(Attr) == F2->getFnAttribute(Attr);
+}
+
+/// \brief Test that there are no attribute conflicts between Caller and Callee
+/// that prevent inlining.
+static bool functionsHaveCompatibleAttributes(Function *Caller,
+ Function *Callee,
+ TargetTransformInfo &TTI) {
+ return TTI.areInlineCompatible(Caller, Callee) &&
+ attributeMatches(Caller, Callee, Attribute::SanitizeAddress) &&
+ attributeMatches(Caller, Callee, Attribute::SanitizeMemory) &&
+ attributeMatches(Caller, Callee, Attribute::SanitizeThread);
+}
+
+InlineCost InlineCostAnalysis::getInlineCost(CallSite CS, Function *Callee,
+ int Threshold) {
+ // Cannot inline indirect calls.
+ if (!Callee)
+ return llvm::InlineCost::getNever();
+
+ // Calls to functions with always-inline attributes should be inlined
+ // whenever possible.
+ if (CS.hasFnAttr(Attribute::AlwaysInline)) {
+ if (isInlineViable(*Callee))
+ return llvm::InlineCost::getAlways();
+ return llvm::InlineCost::getNever();
+ }
+
+ // Never inline functions with conflicting attributes (unless callee has
+ // always-inline attribute).
+ if (!functionsHaveCompatibleAttributes(CS.getCaller(), Callee,
+ TTIWP->getTTI(*Callee)))
+ return llvm::InlineCost::getNever();
+
+ // Don't inline this call if the caller has the optnone attribute.
+ if (CS.getCaller()->hasFnAttribute(Attribute::OptimizeNone))
+ return llvm::InlineCost::getNever();
+
+ // Don't inline functions which can be redefined at link-time to mean
+ // something else. Don't inline functions marked noinline or call sites
+ // marked noinline.
+ if (Callee->mayBeOverridden() ||
+ Callee->hasFnAttribute(Attribute::NoInline) || CS.isNoInline())
+ return llvm::InlineCost::getNever();
+
+ DEBUG(llvm::dbgs() << " Analyzing call of " << Callee->getName()
+ << "...\n");
+
+ CallAnalyzer CA(TTIWP->getTTI(*Callee), ACT, *Callee, Threshold, CS);
+ bool ShouldInline = CA.analyzeCall(CS);
+
+ DEBUG(CA.dump());
+
+ // Check if there was a reason to force inlining or no inlining.
+ if (!ShouldInline && CA.getCost() < CA.getThreshold())
+ return InlineCost::getNever();
+ if (ShouldInline && CA.getCost() >= CA.getThreshold())
+ return InlineCost::getAlways();
+
+ return llvm::InlineCost::get(CA.getCost(), CA.getThreshold());
+}
+
+bool InlineCostAnalysis::isInlineViable(Function &F) {
+ bool ReturnsTwice = F.hasFnAttribute(Attribute::ReturnsTwice);
+ for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
+ // Disallow inlining of functions which contain indirect branches or
+ // blockaddresses.
+ if (isa<IndirectBrInst>(BI->getTerminator()) || BI->hasAddressTaken())
+ return false;
+
+ for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
+ ++II) {
+ CallSite CS(II);
+ if (!CS)
+ continue;
+
+ // Disallow recursive calls.
+ if (&F == CS.getCalledFunction())
+ return false;
+
+ // Disallow calls which expose returns-twice to a function not previously
+ // attributed as such.
+ if (!ReturnsTwice && CS.isCall() &&
+ cast<CallInst>(CS.getInstruction())->canReturnTwice())
+ return false;
+
+ // Disallow inlining functions that call @llvm.localescape. Doing this
+ // correctly would require major changes to the inliner.
+ if (CS.getCalledFunction() &&
+ CS.getCalledFunction()->getIntrinsicID() ==
+ llvm::Intrinsic::localescape)
+ return false;
+ }
+ }
+
+ return true;
+}
;
;===------------------------------------------------------------------------===;
-[common]
-subdirectories = IPA
-
[component_0]
type = Library
name = Analysis
LEVEL = ../..
LIBRARYNAME = LLVMAnalysis
-DIRS = IPA
BUILD_ARCHIVE = 1
include $(LEVEL)/Makefile.common
BitWriter
CodeGen
Core
- IPA
IPO
InstCombine
Linker
type = Library
name = Passes
parent = Libraries
-required_libraries = Analysis Core IPA IPO InstCombine Scalar Support TransformUtils Vectorize
+required_libraries = Analysis Core IPO InstCombine Scalar Support TransformUtils Vectorize
name = IPO
parent = Transforms
library_name = ipo
-required_libraries = Analysis Core IPA InstCombine Scalar Support TransformUtils Vectorize
+required_libraries = Analysis Core InstCombine Scalar Support TransformUtils Vectorize
type = Library
name = TransformUtils
parent = Transforms
-required_libraries = Analysis Core IPA Support
+required_libraries = Analysis Core Support
BitWriter
CodeGen
Core
- IPA
IPO
IRReader
InstCombine
initializeVectorization(Registry);
initializeIPO(Registry);
initializeAnalysis(Registry);
- initializeIPA(Registry);
initializeTransformUtils(Registry);
initializeInstCombine(Registry);
initializeInstrumentation(Registry);
DebugInfoDWARF
DebugInfoPDB
ExecutionEngine
- IPA
IPO
IRReader
InstCombine
set(LLVM_LINK_COMPONENTS
+ Analysis
Core
- IPA
Support
)
BitWriter
CodeGen
Core
- IPA
IPO
IRReader
InstCombine
initializeVectorization(Registry);
initializeIPO(Registry);
initializeAnalysis(Registry);
- initializeIPA(Registry);
initializeTransformUtils(Registry);
initializeInstCombine(Registry);
initializeInstrumentation(Registry);
set(LLVM_LINK_COMPONENTS
- IPA
Analysis
AsmParser
Core
LEVEL = ../..
TESTNAME = Analysis
-LINK_COMPONENTS := ipa analysis asmparser
+LINK_COMPONENTS := analysis asmparser
include $(LEVEL)/Makefile.config
include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
Analysis
AsmParser
Core
- IPA
Support
)
LEVEL = ../..
TESTNAME = IR
-LINK_COMPONENTS := core ipa asmparser
+LINK_COMPONENTS := core analysis asmparser
include $(LEVEL)/Makefile.config
include $(LLVM_SRC_ROOT)/unittests/Makefile.unittest
projects / oota-llvm.git / commitdiff