1 //===- InferFunctionAttrs.cpp - Infer implicit function attributes --------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "llvm/Transforms/IPO/InferFunctionAttrs.h"
10 #include "llvm/Analysis/TargetLibraryInfo.h"
11 #include "llvm/IR/Function.h"
12 #include "llvm/IR/LLVMContext.h"
13 #include "llvm/IR/Module.h"
14 #include "llvm/InitializePasses.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,function_ref<TargetLibraryInfo & (Function &)> GetTLI)22 static bool inferAllPrototypeAttributes(
23 Module &M, function_ref<TargetLibraryInfo &(Function &)> GetTLI) {
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.hasOptNone())
30 Changed |= inferLibFuncAttributes(F, GetTLI(F));
31
32 return Changed;
33 }
34
run(Module & M,ModuleAnalysisManager & AM)35 PreservedAnalyses InferFunctionAttrsPass::run(Module &M,
36 ModuleAnalysisManager &AM) {
37 FunctionAnalysisManager &FAM =
38 AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
39 auto GetTLI = [&FAM](Function &F) -> TargetLibraryInfo & {
40 return FAM.getResult<TargetLibraryAnalysis>(F);
41 };
42
43 if (!inferAllPrototypeAttributes(M, GetTLI))
44 // If we didn't infer anything, preserve all analyses.
45 return PreservedAnalyses::all();
46
47 // Otherwise, we may have changed fundamental function attributes, so clear
48 // out all the passes.
49 return PreservedAnalyses::none();
50 }
51
52 namespace {
53 struct InferFunctionAttrsLegacyPass : public ModulePass {
54 static char ID; // Pass identification, replacement for typeid
InferFunctionAttrsLegacyPass__anon1a2d6a840211::InferFunctionAttrsLegacyPass55 InferFunctionAttrsLegacyPass() : ModulePass(ID) {
56 initializeInferFunctionAttrsLegacyPassPass(
57 *PassRegistry::getPassRegistry());
58 }
59
getAnalysisUsage__anon1a2d6a840211::InferFunctionAttrsLegacyPass60 void getAnalysisUsage(AnalysisUsage &AU) const override {
61 AU.addRequired<TargetLibraryInfoWrapperPass>();
62 }
63
runOnModule__anon1a2d6a840211::InferFunctionAttrsLegacyPass64 bool runOnModule(Module &M) override {
65 if (skipModule(M))
66 return false;
67
68 auto GetTLI = [this](Function &F) -> TargetLibraryInfo & {
69 return this->getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
70 };
71 return inferAllPrototypeAttributes(M, GetTLI);
72 }
73 };
74 }
75
76 char InferFunctionAttrsLegacyPass::ID = 0;
77 INITIALIZE_PASS_BEGIN(InferFunctionAttrsLegacyPass, "inferattrs",
78 "Infer set function attributes", false, false)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)79 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
80 INITIALIZE_PASS_END(InferFunctionAttrsLegacyPass, "inferattrs",
81 "Infer set function attributes", false, false)
82
83 Pass *llvm::createInferFunctionAttrsLegacyPass() {
84 return new InferFunctionAttrsLegacyPass();
85 }
86