1 //===- InferFunctionAttrs.cpp - Infer implicit function attributes --------===// 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 #include "llvm/Transforms/IPO/InferFunctionAttrs.h" 11 #include "llvm/Analysis/TargetLibraryInfo.h" 12 #include "llvm/IR/Function.h" 13 #include "llvm/IR/LLVMContext.h" 14 #include "llvm/IR/Module.h" 15 #include "llvm/Support/Debug.h" 16 #include "llvm/Support/raw_ostream.h" 17 #include "llvm/Transforms/Utils/BuildLibCalls.h" 18 using namespace llvm; 19 20 #define DEBUG_TYPE "inferattrs" 21 22 static bool inferAllPrototypeAttributes(Module &M, 23 const TargetLibraryInfo &TLI) { 24 bool Changed = false; 25 26 for (Function &F : M.functions()) 27 // We only infer things using the prototype and the name; we don't need 28 // definitions. 29 if (F.isDeclaration() && !F.hasFnAttribute((Attribute::OptimizeNone))) 30 Changed |= inferLibFuncAttributes(F, TLI); 31 32 return Changed; 33 } 34 35 PreservedAnalyses InferFunctionAttrsPass::run(Module &M, 36 ModuleAnalysisManager &AM) { 37 auto &TLI = AM.getResult<TargetLibraryAnalysis>(M); 38 39 if (!inferAllPrototypeAttributes(M, TLI)) 40 // If we didn't infer anything, preserve all analyses. 41 return PreservedAnalyses::all(); 42 43 // Otherwise, we may have changed fundamental function attributes, so clear 44 // out all the passes. 45 return PreservedAnalyses::none(); 46 } 47 48 namespace { 49 struct InferFunctionAttrsLegacyPass : public ModulePass { 50 static char ID; // Pass identification, replacement for typeid 51 InferFunctionAttrsLegacyPass() : ModulePass(ID) { 52 initializeInferFunctionAttrsLegacyPassPass( 53 *PassRegistry::getPassRegistry()); 54 } 55 56 void getAnalysisUsage(AnalysisUsage &AU) const override { 57 AU.addRequired<TargetLibraryInfoWrapperPass>(); 58 } 59 60 bool runOnModule(Module &M) override { 61 if (skipModule(M)) 62 return false; 63 64 auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(); 65 return inferAllPrototypeAttributes(M, TLI); 66 } 67 }; 68 } 69 70 char InferFunctionAttrsLegacyPass::ID = 0; 71 INITIALIZE_PASS_BEGIN(InferFunctionAttrsLegacyPass, "inferattrs", 72 "Infer set function attributes", false, false) 73 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass) 74 INITIALIZE_PASS_END(InferFunctionAttrsLegacyPass, "inferattrs", 75 "Infer set function attributes", false, false) 76 77 Pass *llvm::createInferFunctionAttrsLegacyPass() { 78 return new InferFunctionAttrsLegacyPass(); 79 } 80
