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 #include "llvm/Transforms/IPO.h" 15 #include "llvm/Analysis/AliasAnalysis.h" 16 #include "llvm/Analysis/AssumptionCache.h" 17 #include "llvm/Analysis/CallGraph.h" 18 #include "llvm/Analysis/InlineCost.h" 19 #include "llvm/IR/CallSite.h" 20 #include "llvm/IR/CallingConv.h" 21 #include "llvm/IR/DataLayout.h" 22 #include "llvm/IR/Instructions.h" 23 #include "llvm/IR/IntrinsicInst.h" 24 #include "llvm/IR/Module.h" 25 #include "llvm/IR/Type.h" 26 #include "llvm/Transforms/IPO/InlinerPass.h" 27 28 using namespace llvm; 29 30 #define DEBUG_TYPE "inline" 31 32 namespace { 33 34 /// \brief Actual inliner pass implementation. 35 /// 36 /// The common implementation of the inlining logic is shared between this 37 /// inliner pass and the always inliner pass. The two passes use different cost 38 /// analyses to determine when to inline. 39 class SimpleInliner : public Inliner { 40 InlineCostAnalysis *ICA; 41 42 public: 43 SimpleInliner() : Inliner(ID), ICA(nullptr) { 44 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry()); 45 } 46 47 SimpleInliner(int Threshold) 48 : Inliner(ID, Threshold, /*InsertLifetime*/ true), ICA(nullptr) { 49 initializeSimpleInlinerPass(*PassRegistry::getPassRegistry()); 50 } 51 52 static char ID; // Pass identification, replacement for typeid 53 54 InlineCost getInlineCost(CallSite CS) override { 55 return ICA->getInlineCost(CS, getInlineThreshold(CS)); 56 } 57 58 bool runOnSCC(CallGraphSCC &SCC) override; 59 void getAnalysisUsage(AnalysisUsage &AU) const override; 60 }; 61 62 static int computeThresholdFromOptLevels(unsigned OptLevel, 63 unsigned SizeOptLevel) { 64 if (OptLevel > 2) 65 return 275; 66 if (SizeOptLevel == 1) // -Os 67 return 75; 68 if (SizeOptLevel == 2) // -Oz 69 return 25; 70 return 225; 71 } 72 73 } // end anonymous namespace 74 75 char SimpleInliner::ID = 0; 76 INITIALIZE_PASS_BEGIN(SimpleInliner, "inline", 77 "Function Integration/Inlining", false, false) 78 INITIALIZE_AG_DEPENDENCY(AliasAnalysis) 79 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker) 80 INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass) 81 INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis) 82 INITIALIZE_PASS_END(SimpleInliner, "inline", 83 "Function Integration/Inlining", false, false) 84 85 Pass *llvm::createFunctionInliningPass() { return new SimpleInliner(); } 86 87 Pass *llvm::createFunctionInliningPass(int Threshold) { 88 return new SimpleInliner(Threshold); 89 } 90 91 Pass *llvm::createFunctionInliningPass(unsigned OptLevel, 92 unsigned SizeOptLevel) { 93 return new SimpleInliner( 94 computeThresholdFromOptLevels(OptLevel, SizeOptLevel)); 95 } 96 97 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) { 98 ICA = &getAnalysis<InlineCostAnalysis>(); 99 return Inliner::runOnSCC(SCC); 100 } 101 102 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const { 103 AU.addRequired<InlineCostAnalysis>(); 104 Inliner::getAnalysisUsage(AU); 105 } 106