InlineSimple.cpp revision e4aeec003f82a5263ffb168e175e6fca8b6f681d
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/Support/Compiler.h" 24#include "llvm/Transforms/IPO.h" 25#include "llvm/Transforms/IPO/InlinerPass.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 InlineCost getInlineCost(CallSite CS) { 41 return CA.getInlineCost(CS, NeverInline); 42 } 43 float getInlineFudgeFactor(CallSite CS) { 44 return CA.getInlineFudgeFactor(CS); 45 } 46 void resetCachedCostInfo(Function *Caller) { 47 CA.resetCachedCostInfo(Caller); 48 } 49 virtual bool doInitialization(CallGraph &CG); 50 }; 51} 52 53char SimpleInliner::ID = 0; 54static RegisterPass<SimpleInliner> 55X("inline", "Function Integration/Inlining"); 56 57Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } 58 59Pass *llvm::createFunctionInliningPass(int Threshold) { 60 return new SimpleInliner(Threshold); 61} 62 63// doInitialization - Initializes the vector of functions that have been 64// annotated with the noinline attribute. 65bool SimpleInliner::doInitialization(CallGraph &CG) { 66 67 Module &M = CG.getModule(); 68 69 for (Module::iterator I = M.begin(), E = M.end(); 70 I != E; ++I) 71 if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline)) 72 NeverInline.insert(I); 73 74 // Get llvm.noinline 75 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline"); 76 77 if (GV == 0) 78 return false; 79 80 // Don't crash on invalid code 81 if (!GV->hasDefinitiveInitializer()) 82 return false; 83 84 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 85 86 if (InitList == 0) 87 return false; 88 89 // Iterate over each element and add to the NeverInline set 90 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 91 92 // Get Source 93 const Constant *Elt = InitList->getOperand(i); 94 95 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt)) 96 if (CE->getOpcode() == Instruction::BitCast) 97 Elt = CE->getOperand(0); 98 99 // Insert into set of functions to never inline 100 if (const Function *F = dyn_cast<Function>(Elt)) 101 NeverInline.insert(F); 102 } 103 104 return false; 105} 106 107