InlineSimple.cpp revision 2c9c3e73682749016d5885b67ff719f634b37d58
1//===- InlineSimple.cpp - Code to perform simple function inlining --------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements bottom-up inlining of functions into callees. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "inline" 15#include "llvm/CallingConv.h" 16#include "llvm/Instructions.h" 17#include "llvm/IntrinsicInst.h" 18#include "llvm/Module.h" 19#include "llvm/Type.h" 20#include "llvm/Analysis/CallGraph.h" 21#include "llvm/Support/CallSite.h" 22#include "llvm/Support/Compiler.h" 23#include "llvm/Transforms/IPO.h" 24#include "llvm/Transforms/IPO/InlinerPass.h" 25#include "llvm/Transforms/Utils/InlineCost.h" 26#include "llvm/ADT/SmallPtrSet.h" 27 28using namespace llvm; 29 30namespace { 31 32 class VISIBILITY_HIDDEN SimpleInliner : public Inliner { 33 // Functions that are never inlined 34 SmallPtrSet<const Function*, 16> NeverInline; 35 InlineCostAnalyzer CA; 36 public: 37 SimpleInliner() : Inliner(&ID) {} 38 SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {} 39 static char ID; // Pass identification, replacement for typeid 40 int getInlineCost(CallSite CS) { 41 return CA.getInlineCost(CS, NeverInline); 42 } 43 float getInlineFudgeFactor(CallSite CS) { 44 return CA.getInlineFudgeFactor(CS); 45 } 46 virtual bool doInitialization(CallGraph &CG); 47 }; 48} 49 50char SimpleInliner::ID = 0; 51static RegisterPass<SimpleInliner> 52X("inline", "Function Integration/Inlining"); 53 54Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } 55 56Pass *llvm::createFunctionInliningPass(int Threshold) { 57 return new SimpleInliner(Threshold); 58} 59 60// doInitialization - Initializes the vector of functions that have been 61// annotated with the noinline attribute. 62bool SimpleInliner::doInitialization(CallGraph &CG) { 63 64 Module &M = CG.getModule(); 65 66 for (Module::iterator I = M.begin(), E = M.end(); 67 I != E; ++I) 68 if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline)) 69 NeverInline.insert(I); 70 71 // Get llvm.noinline 72 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline"); 73 74 if (GV == 0) 75 return false; 76 77 // Don't crash on invalid code 78 if (!GV->hasInitializer()) 79 return false; 80 81 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 82 83 if (InitList == 0) 84 return false; 85 86 // Iterate over each element and add to the NeverInline set 87 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 88 89 // Get Source 90 const Constant *Elt = InitList->getOperand(i); 91 92 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt)) 93 if (CE->getOpcode() == Instruction::BitCast) 94 Elt = CE->getOperand(0); 95 96 // Insert into set of functions to never inline 97 if (const Function *F = dyn_cast<Function>(Elt)) 98 NeverInline.insert(F); 99 } 100 101 return false; 102} 103 104