InlineSimple.cpp revision 758296df4ac666c9fe3c47fadf3545c2df26d8a1
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 virtual bool doInitialization(CallGraph &CG); 44 }; 45 char SimpleInliner::ID = 0; 46 RegisterPass<SimpleInliner> X("inline", "Function Integration/Inlining"); 47} 48 49Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } 50 51Pass *llvm::createFunctionInliningPass(int Threshold) { 52 return new SimpleInliner(Threshold); 53} 54 55// doInitialization - Initializes the vector of functions that have been 56// annotated with the noinline attribute. 57bool SimpleInliner::doInitialization(CallGraph &CG) { 58 59 Module &M = CG.getModule(); 60 61 // Get llvm.noinline 62 GlobalVariable *GV = M.getNamedGlobal("llvm.noinline"); 63 64 if (GV == 0) 65 return false; 66 67 // Don't crash on invalid code 68 if (!GV->hasInitializer()) 69 return false; 70 71 const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer()); 72 73 if (InitList == 0) 74 return false; 75 76 // Iterate over each element and add to the NeverInline set 77 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 78 79 // Get Source 80 const Constant *Elt = InitList->getOperand(i); 81 82 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt)) 83 if (CE->getOpcode() == Instruction::BitCast) 84 Elt = CE->getOperand(0); 85 86 // Insert into set of functions to never inline 87 if (const Function *F = dyn_cast<Function>(Elt)) 88 NeverInline.insert(F); 89 } 90 91 return false; 92} 93 94