1 //===- InlineAlways.cpp - Code to inline always_inline functions ----------===// 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 a custom inliner that handles only functions that 11 // are marked as "always inline". 12 // 13 //===----------------------------------------------------------------------===// 14 15 #define DEBUG_TYPE "inline" 16 #include "llvm/CallingConv.h" 17 #include "llvm/Instructions.h" 18 #include "llvm/IntrinsicInst.h" 19 #include "llvm/Module.h" 20 #include "llvm/Type.h" 21 #include "llvm/Analysis/CallGraph.h" 22 #include "llvm/Analysis/InlineCost.h" 23 #include "llvm/Support/CallSite.h" 24 #include "llvm/Transforms/IPO.h" 25 #include "llvm/Transforms/IPO/InlinerPass.h" 26 #include "llvm/ADT/SmallPtrSet.h" 27 28 using namespace llvm; 29 30 namespace { 31 32 // AlwaysInliner only inlines functions that are mark as "always inline". 33 class AlwaysInliner : public Inliner { 34 // Functions that are never inlined 35 SmallPtrSet<const Function*, 16> NeverInline; 36 InlineCostAnalyzer CA; 37 public: 38 // Use extremely low threshold. 39 AlwaysInliner() : Inliner(ID, -2000000000) { 40 initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry()); 41 } 42 static char ID; // Pass identification, replacement for typeid 43 InlineCost getInlineCost(CallSite CS) { 44 return CA.getInlineCost(CS, NeverInline); 45 } 46 float getInlineFudgeFactor(CallSite CS) { 47 return CA.getInlineFudgeFactor(CS); 48 } 49 void resetCachedCostInfo(Function *Caller) { 50 CA.resetCachedCostInfo(Caller); 51 } 52 void growCachedCostInfo(Function* Caller, Function* Callee) { 53 CA.growCachedCostInfo(Caller, Callee); 54 } 55 virtual bool doFinalization(CallGraph &CG) { 56 return removeDeadFunctions(CG, &NeverInline); 57 } 58 virtual bool doInitialization(CallGraph &CG); 59 void releaseMemory() { 60 CA.clear(); 61 } 62 }; 63 } 64 65 char AlwaysInliner::ID = 0; 66 INITIALIZE_PASS_BEGIN(AlwaysInliner, "always-inline", 67 "Inliner for always_inline functions", false, false) 68 INITIALIZE_AG_DEPENDENCY(CallGraph) 69 INITIALIZE_PASS_END(AlwaysInliner, "always-inline", 70 "Inliner for always_inline functions", false, false) 71 72 Pass *llvm::createAlwaysInlinerPass() { return new AlwaysInliner(); } 73 74 // doInitialization - Initializes the vector of functions that have not 75 // been annotated with the "always inline" attribute. 76 bool AlwaysInliner::doInitialization(CallGraph &CG) { 77 Module &M = CG.getModule(); 78 79 for (Module::iterator I = M.begin(), E = M.end(); 80 I != E; ++I) 81 if (!I->isDeclaration() && !I->hasFnAttr(Attribute::AlwaysInline)) 82 NeverInline.insert(I); 83 84 return false; 85 } 86