//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
-#include "Inliner.h"
+#define DEBUG_TYPE "inline"
#include "llvm/Module.h"
#include "llvm/Instructions.h"
#include "llvm/Analysis/CallGraph.h"
#include "llvm/Support/CallSite.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/IPO/InlinerPass.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/Statistic.h"
-#include <iostream>
#include <set>
using namespace llvm;
-namespace {
- Statistic<> NumInlined("inline", "Number of functions inlined");
- Statistic<> NumDeleted("inline",
- "Number of functions deleted because all callers found");
- cl::opt<unsigned> // FIXME: 200 is VERY conservative
- InlineLimit("inline-threshold", cl::Hidden, cl::init(200),
+STATISTIC(NumInlined, "Number of functions inlined");
+STATISTIC(NumDeleted, "Number of functions deleted because all callers found");
+
+static cl::opt<int>
+InlineLimit("inline-threshold", cl::Hidden, cl::init(200),
cl::desc("Control the amount of inlining to perform (default = 200)"));
-}
-Inliner::Inliner() : InlineThreshold(InlineLimit) {}
+Inliner::Inliner(void *ID)
+ : CallGraphSCCPass(ID), InlineThreshold(InlineLimit) {}
+
+Inliner::Inliner(void *ID, int Threshold)
+ : CallGraphSCCPass(ID), InlineThreshold(Threshold) {}
+
+/// getAnalysisUsage - 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 Inliner::getAnalysisUsage(AnalysisUsage &Info) const {
+ Info.addRequired<TargetData>();
+ CallGraphSCCPass::getAnalysisUsage(Info);
+}
// InlineCallIfPossible - If it is possible to inline the specified call site,
// do so and update the CallGraph for this operation.
static bool InlineCallIfPossible(CallSite CS, CallGraph &CG,
- const std::set<Function*> &SCCFunctions) {
+ const std::set<Function*> &SCCFunctions,
+ const TargetData &TD) {
Function *Callee = CS.getCalledFunction();
- if (!InlineFunction(CS, &CG)) return false;
+ Function *Caller = CS.getCaller();
+
+ if (!InlineFunction(CS, &CG, &TD)) return false;
+
+ // If the inlined function had a higher stack protection level than the
+ // calling function, then bump up the caller's stack protection level.
+ if (Callee->hasFnAttr(Attribute::StackProtectReq))
+ Caller->addFnAttr(Attribute::StackProtectReq);
+ else if (Callee->hasFnAttr(Attribute::StackProtect) &&
+ !Caller->hasFnAttr(Attribute::StackProtectReq))
+ Caller->addFnAttr(Attribute::StackProtect);
// If we inlined the last possible call site to the function, delete the
// function body now.
- if (Callee->use_empty() && Callee->hasInternalLinkage() &&
+ if (Callee->use_empty() && Callee->hasLocalLinkage() &&
!SCCFunctions.count(Callee)) {
- DEBUG(std::cerr << " -> Deleting dead function: "
- << Callee->getName() << "\n");
+ DOUT << " -> Deleting dead function: " << Callee->getName() << "\n";
+ CallGraphNode *CalleeNode = CG[Callee];
// Remove any call graph edges from the callee to its callees.
- CallGraphNode *CalleeNode = CG[Callee];
- while (CalleeNode->begin() != CalleeNode->end())
- CalleeNode->removeCallEdgeTo((CalleeNode->end()-1)->second);
+ CalleeNode->removeAllCalledFunctions();
// Removing the node for callee from the call graph and delete it.
delete CG.removeFunctionFromModule(CalleeNode);
}
return true;
}
+
+/// shouldInline - Return true if the inliner should attempt to inline
+/// at the given CallSite.
+bool Inliner::shouldInline(CallSite CS) {
+ InlineCost IC = getInlineCost(CS);
+ float FudgeFactor = getInlineFudgeFactor(CS);
+
+ if (IC.isAlways()) {
+ DOUT << " Inlining: cost=always"
+ << ", Call: " << *CS.getInstruction();
+ return true;
+ }
+
+ if (IC.isNever()) {
+ DOUT << " NOT Inlining: cost=never"
+ << ", Call: " << *CS.getInstruction();
+ return false;
+ }
+
+ int Cost = IC.getValue();
+ int CurrentThreshold = InlineThreshold;
+ Function *Fn = CS.getCaller();
+ if (Fn && !Fn->isDeclaration()
+ && Fn->hasFnAttr(Attribute::OptimizeForSize)
+ && InlineThreshold != 50) {
+ CurrentThreshold = 50;
+ }
+
+ if (Cost >= (int)(CurrentThreshold * FudgeFactor)) {
+ DOUT << " NOT Inlining: cost=" << Cost
+ << ", Call: " << *CS.getInstruction();
+ return false;
+ } else {
+ DOUT << " Inlining: cost=" << Cost
+ << ", Call: " << *CS.getInstruction();
+ return true;
+ }
+}
bool Inliner::runOnSCC(const std::vector<CallGraphNode*> &SCC) {
CallGraph &CG = getAnalysis<CallGraph>();
std::set<Function*> SCCFunctions;
- DEBUG(std::cerr << "Inliner visiting SCC:");
+ DOUT << "Inliner visiting SCC:";
for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
Function *F = SCC[i]->getFunction();
if (F) SCCFunctions.insert(F);
- DEBUG(std::cerr << " " << (F ? F->getName() : "INDIRECTNODE"));
+ DOUT << " " << (F ? F->getName() : "INDIRECTNODE");
}
// Scan through and identify all call sites ahead of time so that we only
for (BasicBlock::iterator I = BB->begin(); I != BB->end(); ++I) {
CallSite CS = CallSite::get(I);
if (CS.getInstruction() && (!CS.getCalledFunction() ||
- !CS.getCalledFunction()->isExternal()))
+ !CS.getCalledFunction()->isDeclaration()))
CallSites.push_back(CS);
}
- DEBUG(std::cerr << ": " << CallSites.size() << " call sites.\n");
+ DOUT << ": " << CallSites.size() << " call sites.\n";
// Now that we have all of the call sites, move the ones to functions in the
// current SCC to the end of the list.
for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi)
if (Function *Callee = CallSites[CSi].getCalledFunction()) {
// Calls to external functions are never inlinable.
- if (Callee->isExternal() ||
- CallSites[CSi].getInstruction()->getParent()->getParent() ==Callee){
- std::swap(CallSites[CSi], CallSites.back());
- CallSites.pop_back();
+ if (Callee->isDeclaration()) {
+ if (SCC.size() == 1) {
+ std::swap(CallSites[CSi], CallSites.back());
+ CallSites.pop_back();
+ } else {
+ // Keep the 'in SCC / not in SCC' boundary correct.
+ CallSites.erase(CallSites.begin()+CSi);
+ }
--CSi;
continue;
}
// If the policy determines that we should inline this function,
// try to do so.
CallSite CS = CallSites[CSi];
- int InlineCost = getInlineCost(CS);
- if (InlineCost >= (int)InlineThreshold) {
- DEBUG(std::cerr << " NOT Inlining: cost=" << InlineCost
- << ", Call: " << *CS.getInstruction());
- } else {
- DEBUG(std::cerr << " Inlining: cost=" << InlineCost
- << ", Call: " << *CS.getInstruction());
-
+ if (shouldInline(CS)) {
+ Function *Caller = CS.getCaller();
// Attempt to inline the function...
- if (InlineCallIfPossible(CS, CG, SCCFunctions)) {
- // Remove this call site from the list.
- std::swap(CallSites[CSi], CallSites.back());
- CallSites.pop_back();
+ if (InlineCallIfPossible(CS, CG, SCCFunctions,
+ getAnalysis<TargetData>())) {
+ // Remove any cached cost info for this caller, as inlining the callee
+ // has increased the size of the caller (which may be the same as the
+ // callee).
+ resetCachedCostInfo(Caller);
+
+ // Remove this call site from the list. If possible, use
+ // swap/pop_back for efficiency, but do not use it if doing so would
+ // move a call site to a function in this SCC before the
+ // 'FirstCallInSCC' barrier.
+ if (SCC.size() == 1) {
+ std::swap(CallSites[CSi], CallSites.back());
+ CallSites.pop_back();
+ } else {
+ CallSites.erase(CallSites.begin()+CSi);
+ }
--CSi;
++NumInlined;
// doFinalization - Remove now-dead linkonce functions at the end of
// processing to avoid breaking the SCC traversal.
bool Inliner::doFinalization(CallGraph &CG) {
+ return removeDeadFunctions(CG);
+}
+
+ /// removeDeadFunctions - Remove dead functions that are not included in
+ /// DNR (Do Not Remove) list.
+bool Inliner::removeDeadFunctions(CallGraph &CG,
+ SmallPtrSet<const Function *, 16> *DNR) {
std::set<CallGraphNode*> FunctionsToRemove;
// Scan for all of the functions, looking for ones that should now be removed
// them.
F->removeDeadConstantUsers();
- if ((F->hasLinkOnceLinkage() || F->hasInternalLinkage()) &&
+ if (DNR && DNR->count(F))
+ continue;
+
+ if ((F->hasLinkOnceLinkage() || F->hasLocalLinkage()) &&
F->use_empty()) {
// Remove any call graph edges from the function to its callees.
- while (CGN->begin() != CGN->end())
- CGN->removeCallEdgeTo((CGN->end()-1)->second);
+ CGN->removeAllCalledFunctions();
// Remove any edges from the external node to the function's call graph
// node. These edges might have been made irrelegant due to