54 lines · cpp
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-exception6//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/Module.h"13#include "llvm/Transforms/Utils/BuildLibCalls.h"14#include "llvm/Transforms/Utils/Local.h"15using namespace llvm;16 17#define DEBUG_TYPE "inferattrs"18 19static bool inferAllPrototypeAttributes(20 Module &M, function_ref<TargetLibraryInfo &(Function &)> GetTLI) {21 bool Changed = false;22 23 for (Function &F : M.functions())24 // We only infer things using the prototype and the name; we don't need25 // definitions. This ensures libfuncs are annotated and also allows our26 // CGSCC inference to avoid needing to duplicate the inference from other27 // attribute logic on all calls to declarations (as declarations aren't28 // explicitly visited by CGSCC passes in the new pass manager.)29 if (F.isDeclaration() && !F.hasOptNone()) {30 if (!F.hasFnAttribute(Attribute::NoBuiltin))31 Changed |= inferNonMandatoryLibFuncAttrs(F, GetTLI(F));32 Changed |= inferAttributesFromOthers(F);33 }34 35 return Changed;36}37 38PreservedAnalyses InferFunctionAttrsPass::run(Module &M,39 ModuleAnalysisManager &AM) {40 FunctionAnalysisManager &FAM =41 AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();42 auto GetTLI = [&FAM](Function &F) -> TargetLibraryInfo & {43 return FAM.getResult<TargetLibraryAnalysis>(F);44 };45 46 if (!inferAllPrototypeAttributes(M, GetTLI))47 // If we didn't infer anything, preserve all analyses.48 return PreservedAnalyses::all();49 50 // Otherwise, we may have changed fundamental function attributes, so clear51 // out all the passes.52 return PreservedAnalyses::none();53}54