//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "functionattrs"
#include "llvm/Transforms/IPO.h"
#include "llvm/ADT/SCCIterator.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/CallGraphSCCPass.h"
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/InstIterator.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
-#include "llvm/Support/InstIterator.h"
#include "llvm/Target/TargetLibraryInfo.h"
using namespace llvm;
+#define DEBUG_TYPE "functionattrs"
+
STATISTIC(NumReadNone, "Number of functions marked readnone");
STATISTIC(NumReadOnly, "Number of functions marked readonly");
STATISTIC(NumNoCapture, "Number of arguments marked nocapture");
namespace {
struct FunctionAttrs : public CallGraphSCCPass {
static char ID; // Pass identification, replacement for typeid
- FunctionAttrs() : CallGraphSCCPass(ID), AA(0) {
+ FunctionAttrs() : CallGraphSCCPass(ID), AA(nullptr) {
initializeFunctionAttrsPass(*PassRegistry::getPassRegistry());
}
// runOnSCC - Analyze the SCC, performing the transformation if possible.
- bool runOnSCC(CallGraphSCC &SCC);
+ bool runOnSCC(CallGraphSCC &SCC) override;
// AddReadAttrs - Deduce readonly/readnone attributes for the SCC.
bool AddReadAttrs(const CallGraphSCC &SCC);
// call declarations.
bool annotateLibraryCalls(const CallGraphSCC &SCC);
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
AU.addRequired<AliasAnalysis>();
AU.addRequired<TargetLibraryInfo>();
char FunctionAttrs::ID = 0;
INITIALIZE_PASS_BEGIN(FunctionAttrs, "functionattrs",
"Deduce function attributes", false, false)
-INITIALIZE_AG_DEPENDENCY(CallGraph)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfo)
INITIALIZE_PASS_END(FunctionAttrs, "functionattrs",
"Deduce function attributes", false, false)
for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
Function *F = (*I)->getFunction();
- if (F == 0)
- // External node - may write memory. Just give up.
+ if (!F || F->hasFnAttribute(Attribute::OptimizeNone))
+ // External node or node we don't want to optimize - assume it may write
+ // memory and give up.
return false;
AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(F);
CI != CE; ++CI) {
Value *Arg = *CI;
if (Arg->getType()->isPointerTy()) {
+ AAMDNodes AAInfo;
+ I->getAAMetadata(AAInfo);
+
AliasAnalysis::Location Loc(Arg,
- AliasAnalysis::UnknownSize,
- I->getMetadata(LLVMContext::MD_tbaa));
+ AliasAnalysis::UnknownSize, AAInfo);
if (!AA->pointsToConstantMemory(Loc, /*OrLocal=*/true)) {
if (MRB & AliasAnalysis::Mod)
// Writes non-local memory. Give up.
ArgumentGraphNode SyntheticRoot;
public:
- ArgumentGraph() { SyntheticRoot.Definition = 0; }
+ ArgumentGraph() { SyntheticRoot.Definition = nullptr; }
typedef SmallVectorImpl<ArgumentGraphNode*>::iterator iterator;
ArgumentUsesTracker(const SmallPtrSet<Function*, 8> &SCCNodes)
: Captured(false), SCCNodes(SCCNodes) {}
- void tooManyUses() { Captured = true; }
+ void tooManyUses() override { Captured = true; }
- bool captured(Use *U) {
+ bool captured(const Use *U) override {
CallSite CS(U->getUser());
if (!CS.getInstruction()) { Captured = true; return true; }
}
}
assert(Found && "Capturing call-site captured nothing?");
+ (void)Found;
return false;
}
SmallSet<Use*, 32> Visited;
int Count = 0;
+ // inalloca arguments are always clobbered by the call.
+ if (A->hasInAllocaAttr())
+ return Attribute::None;
+
bool IsRead = false;
// We don't need to track IsWritten. If A is written to, return immediately.
- for (Value::use_iterator UI = A->use_begin(), UE = A->use_end();
- UI != UE; ++UI) {
+ for (Use &U : A->uses()) {
if (Count++ >= 20)
return Attribute::None;
- Use *U = &UI.getUse();
- Visited.insert(U);
- Worklist.push_back(U);
+ Visited.insert(&U);
+ Worklist.push_back(&U);
}
while (!Worklist.empty()) {
case Instruction::GetElementPtr:
case Instruction::PHI:
case Instruction::Select:
+ case Instruction::AddrSpaceCast:
// The original value is not read/written via this if the new value isn't.
- for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end();
- UI != UE; ++UI) {
- Use *U = &UI.getUse();
- if (Visited.insert(U))
- Worklist.push_back(U);
- }
+ for (Use &UU : I->uses())
+ if (Visited.insert(&UU))
+ Worklist.push_back(&UU);
break;
case Instruction::Call:
case Instruction::Invoke: {
+ bool Captures = true;
+
+ if (I->getType()->isVoidTy())
+ Captures = false;
+
+ auto AddUsersToWorklistIfCapturing = [&] {
+ if (Captures)
+ for (Use &UU : I->uses())
+ if (Visited.insert(&UU))
+ Worklist.push_back(&UU);
+ };
+
CallSite CS(I);
- if (CS.doesNotAccessMemory())
+ if (CS.doesNotAccessMemory()) {
+ AddUsersToWorklistIfCapturing();
continue;
+ }
Function *F = CS.getCalledFunction();
if (!F) {
if (CS.onlyReadsMemory()) {
IsRead = true;
+ AddUsersToWorklistIfCapturing();
continue;
}
return Attribute::None;
"More params than args in non-varargs call.");
return Attribute::None;
}
+ Captures &= !CS.doesNotCapture(A - B);
if (SCCNodes.count(AI))
continue;
if (!CS.onlyReadsMemory() && !CS.onlyReadsMemory(A - B))
IsRead = true;
}
}
+ AddUsersToWorklistIfCapturing();
break;
}
// looking up whether a given CallGraphNode is in this SCC.
for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
Function *F = (*I)->getFunction();
- if (F && !F->isDeclaration() && !F->mayBeOverridden())
+ if (F && !F->isDeclaration() && !F->mayBeOverridden() &&
+ !F->hasFnAttribute(Attribute::OptimizeNone))
SCCNodes.insert(F);
}
for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
Function *F = (*I)->getFunction();
- if (F == 0)
- // External node - only a problem for arguments that we pass to it.
+ if (!F || F->hasFnAttribute(Attribute::OptimizeNone))
+ // External node or function we're trying not to optimize - only a problem
+ // for arguments that we pass to it.
continue;
// Definitions with weak linkage may be overridden at linktime with
// made. If the definition doesn't have a 'nocapture' attribute by now, it
// captures.
- for (scc_iterator<ArgumentGraph*> I = scc_begin(&AG), E = scc_end(&AG);
- I != E; ++I) {
- std::vector<ArgumentGraphNode*> &ArgumentSCC = *I;
+ for (scc_iterator<ArgumentGraph*> I = scc_begin(&AG); !I.isAtEnd(); ++I) {
+ const std::vector<ArgumentGraphNode *> &ArgumentSCC = *I;
if (ArgumentSCC.size() == 1) {
if (!ArgumentSCC[0]->Definition) continue; // synthetic root node
}
bool SCCCaptured = false;
- for (std::vector<ArgumentGraphNode*>::iterator I = ArgumentSCC.begin(),
- E = ArgumentSCC.end(); I != E && !SCCCaptured; ++I) {
+ for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end();
+ I != E && !SCCCaptured; ++I) {
ArgumentGraphNode *Node = *I;
if (Node->Uses.empty()) {
if (!Node->Definition->hasNoCaptureAttr())
SmallPtrSet<Argument*, 8> ArgumentSCCNodes;
// Fill ArgumentSCCNodes with the elements of the ArgumentSCC. Used for
// quickly looking up whether a given Argument is in this ArgumentSCC.
- for (std::vector<ArgumentGraphNode*>::iterator I = ArgumentSCC.begin(),
- E = ArgumentSCC.end(); I != E; ++I) {
+ for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end(); I != E; ++I) {
ArgumentSCCNodes.insert((*I)->Definition);
}
- for (std::vector<ArgumentGraphNode*>::iterator I = ArgumentSCC.begin(),
- E = ArgumentSCC.end(); I != E && !SCCCaptured; ++I) {
+ for (auto I = ArgumentSCC.begin(), E = ArgumentSCC.end();
+ I != E && !SCCCaptured; ++I) {
ArgumentGraphNode *N = *I;
for (SmallVectorImpl<ArgumentGraphNode*>::iterator UI = N->Uses.begin(),
UE = N->Uses.end(); UI != UE; ++UI) {
// Extend the analysis by looking upwards.
case Instruction::BitCast:
case Instruction::GetElementPtr:
+ case Instruction::AddrSpaceCast:
FlowsToReturn.insert(RVI->getOperand(0));
continue;
case Instruction::Select: {
for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
Function *F = (*I)->getFunction();
- if (F == 0)
- // External node - skip it;
+ if (!F || F->hasFnAttribute(Attribute::OptimizeNone))
+ // External node or node we don't want to optimize - skip it;
return false;
// Already noalias.
/// given function and set any applicable attributes. Returns true
/// if any attributes were set and false otherwise.
bool FunctionAttrs::inferPrototypeAttributes(Function &F) {
+ if (F.hasFnAttribute(Attribute::OptimizeNone))
+ return false;
+
FunctionType *FTy = F.getFunctionType();
LibFunc::Func TheLibFunc;
if (!(TLI->getLibFunc(F.getName(), TheLibFunc) && TLI->has(TheLibFunc)))
setDoesNotThrow(F);
setDoesNotCapture(F, 1);
setDoesNotCapture(F, 2);
+ break;
default:
// Didn't mark any attributes.
return false;
for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
Function *F = (*I)->getFunction();
- if (F != 0 && F->isDeclaration())
+ if (F && F->isDeclaration())
MadeChange |= inferPrototypeAttributes(*F);
}