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
inferAllPrototypeAttributes(Module & M,const TargetLibraryInfo & TLI)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
run(Module & M,ModuleAnalysisManager & AM)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
InferFunctionAttrsLegacyPass__anonb10acfd00111::InferFunctionAttrsLegacyPass51 InferFunctionAttrsLegacyPass() : ModulePass(ID) {
52 initializeInferFunctionAttrsLegacyPassPass(
53 *PassRegistry::getPassRegistry());
54 }
55
getAnalysisUsage__anonb10acfd00111::InferFunctionAttrsLegacyPass56 void getAnalysisUsage(AnalysisUsage &AU) const override {
57 AU.addRequired<TargetLibraryInfoWrapperPass>();
58 }
59
runOnModule__anonb10acfd00111::InferFunctionAttrsLegacyPass60 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)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)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