InlineSimple.cpp revision 198892
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/Analysis/InlineCost.h" 22#include "llvm/Support/CallSite.h" 23#include "llvm/Transforms/IPO.h" 24#include "llvm/Transforms/IPO/InlinerPass.h" 25#include "llvm/ADT/SmallPtrSet.h" 26 27using namespace llvm; 28 29namespace { 30 31 class SimpleInliner : public Inliner { 32 // Functions that are never inlined 33 SmallPtrSet<const Function*, 16> NeverInline; 34 InlineCostAnalyzer CA; 35 public: 36 SimpleInliner() : Inliner(&ID) {} 37 SimpleInliner(int Threshold) : Inliner(&ID, Threshold) {} 38 static char ID; // Pass identification, replacement for typeid 39 InlineCost getInlineCost(CallSite CS) { 40 return CA.getInlineCost(CS, NeverInline); 41 } 42 float getInlineFudgeFactor(CallSite CS) { 43 return CA.getInlineFudgeFactor(CS); 44 } 45 void resetCachedCostInfo(Function *Caller) { 46 CA.resetCachedCostInfo(Caller); 47 } 48 virtual bool doInitialization(CallGraph &CG); 49 }; 50} 51 52char SimpleInliner::ID = 0; 53static RegisterPass<SimpleInliner> 54X("inline", "Function Integration/Inlining"); 55 56Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } 57 58Pass *llvm::createFunctionInliningPass(int Threshold) { 59 return new SimpleInliner(Threshold); 60} 61 62// doInitialization - Initializes the vector of functions that have been 63// annotated with the noinline attribute. 64bool SimpleInliner::doInitialization(CallGraph &CG) { 65 66 Module &M = CG.getModule(); 67 68 for (Module::iterator I = M.begin(), E = M.end(); 69 I != E; ++I) 70 if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline)) 71 NeverInline.insert(I); 72 73 // Get llvm.noinline 74 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline"); 75 76 if (GV == 0) 77 return false; 78 79 // Don't crash on invalid code 80 if (!GV->hasDefinitiveInitializer()) 81 return false; 82 83 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 84 85 if (InitList == 0) 86 return false; 87 88 // Iterate over each element and add to the NeverInline set 89 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 90 91 // Get Source 92 const Constant *Elt = InitList->getOperand(i); 93 94 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt)) 95 if (CE->getOpcode() == Instruction::BitCast) 96 Elt = CE->getOperand(0); 97 98 // Insert into set of functions to never inline 99 if (const Function *F = dyn_cast<Function>(Elt)) 100 NeverInline.insert(F); 101 } 102 103 return false; 104} 105 106