145 lines · cpp
1//===- SandboxVectorizer.cpp - Vectorizer based on Sandbox IR -------------===//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/Vectorize/SandboxVectorizer/SandboxVectorizer.h"10#include "llvm/Analysis/TargetTransformInfo.h"11#include "llvm/IR/Module.h"12#include "llvm/SandboxIR/Constant.h"13#include "llvm/Support/CommandLine.h"14#include "llvm/Support/Regex.h"15#include "llvm/Transforms/Vectorize/SandboxVectorizer/Debug.h"16#include "llvm/Transforms/Vectorize/SandboxVectorizer/SandboxVectorizerPassBuilder.h"17 18using namespace llvm;19 20static cl::opt<bool>21 PrintPassPipeline("sbvec-print-pass-pipeline", cl::init(false), cl::Hidden,22 cl::desc("Prints the pass pipeline and returns."));23 24/// A magic string for the default pass pipeline.25static const char *DefaultPipelineMagicStr = "*";26 27static cl::opt<std::string> UserDefinedPassPipeline(28 "sbvec-passes", cl::init(DefaultPipelineMagicStr), cl::Hidden,29 cl::desc("Comma-separated list of vectorizer passes. If not set "30 "we run the predefined pipeline."));31 32// This option is useful for bisection debugging.33// For example you may use it to figure out which filename is the one causing a34// miscompile. You can specify a regex for the filename like: "/[a-m][^/]*"35// which will enable any file name starting with 'a' to 'm' and disable the36// rest. If the miscompile goes away, then we try "/[n-z][^/]*" for the other37// half of the range, from 'n' to 'z'. If we can reproduce the miscompile then38// we can keep looking in [n-r] and [s-z] and so on, in a binary-search fashion.39//40// Please note that we are using [^/]* and not .* to make sure that we are41// matching the actual filename and not some other directory in the path.42cl::opt<std::string> AllowFiles(43 "sbvec-allow-files", cl::init(".*"), cl::Hidden,44 cl::desc("Run the vectorizer only on file paths that match any in the "45 "list of comma-separated regex's."));46static constexpr char AllowFilesDelim = ',';47 48SandboxVectorizerPass::SandboxVectorizerPass() : FPM("fpm") {49 if (UserDefinedPassPipeline == DefaultPipelineMagicStr) {50 // TODO: Add passes to the default pipeline. It currently contains:51 // - Seed collection, which creates seed regions and runs the pipeline52 // - Bottom-up Vectorizer pass that starts from a seed53 // - Accept or revert IR state pass54 FPM.setPassPipeline(55 "seed-collection<tr-save,bottom-up-vec,tr-accept-or-revert>",56 sandboxir::SandboxVectorizerPassBuilder::createFunctionPass);57 } else {58 // Create the user-defined pipeline.59 FPM.setPassPipeline(60 UserDefinedPassPipeline,61 sandboxir::SandboxVectorizerPassBuilder::createFunctionPass);62 }63}64 65SandboxVectorizerPass::SandboxVectorizerPass(SandboxVectorizerPass &&) =66 default;67 68SandboxVectorizerPass::~SandboxVectorizerPass() = default;69 70PreservedAnalyses SandboxVectorizerPass::run(Function &F,71 FunctionAnalysisManager &AM) {72 TTI = &AM.getResult<TargetIRAnalysis>(F);73 AA = &AM.getResult<AAManager>(F);74 SE = &AM.getResult<ScalarEvolutionAnalysis>(F);75 76 bool Changed = runImpl(F);77 if (!Changed)78 return PreservedAnalyses::all();79 80 PreservedAnalyses PA;81 PA.preserveSet<CFGAnalyses>();82 return PA;83}84 85bool SandboxVectorizerPass::allowFile(const std::string &SrcFilePath) {86 // Iterate over all files in AllowFiles separated by `AllowFilesDelim`.87 size_t DelimPos = 0;88 do {89 size_t LastPos = DelimPos != 0 ? DelimPos + 1 : DelimPos;90 DelimPos = AllowFiles.find(AllowFilesDelim, LastPos);91 auto FileNameToMatch = AllowFiles.substr(LastPos, DelimPos - LastPos);92 if (FileNameToMatch.empty())93 return false;94 // Note: This only runs when debugging so its OK not to reuse the regex.95 Regex FileNameRegex(".*" + FileNameToMatch + "$");96 assert(FileNameRegex.isValid() && "Bad regex!");97 if (FileNameRegex.match(SrcFilePath))98 return true;99 } while (DelimPos != std::string::npos);100 return false;101}102 103bool SandboxVectorizerPass::runImpl(Function &LLVMF) {104 if (Ctx == nullptr)105 Ctx = std::make_unique<sandboxir::Context>(LLVMF.getContext());106 107 if (PrintPassPipeline) {108 FPM.printPipeline(outs());109 return false;110 }111 112 // This is used for debugging.113 if (LLVM_UNLIKELY(AllowFiles != ".*")) {114 const auto &SrcFilePath = LLVMF.getParent()->getSourceFileName();115 if (!allowFile(SrcFilePath))116 return false;117 }118 119 // If the target claims to have no vector registers early return.120 if (!TTI->getNumberOfRegisters(TTI->getRegisterClassForType(true))) {121 LLVM_DEBUG(dbgs() << DEBUG_PREFIX122 << "Target has no vector registers, return.\n");123 return false;124 }125 LLVM_DEBUG(dbgs() << DEBUG_PREFIX << "Analyzing " << LLVMF.getName()126 << ".\n");127 // Early return if the attribute NoImplicitFloat is used.128 if (LLVMF.hasFnAttribute(Attribute::NoImplicitFloat)) {129 LLVM_DEBUG(dbgs() << DEBUG_PREFIX130 << "NoImplicitFloat attribute, return.\n");131 return false;132 }133 134 // Create SandboxIR for LLVMF and run BottomUpVec on it.135 sandboxir::Function &F = *Ctx->createFunction(&LLVMF);136 sandboxir::Analyses A(*AA, *SE, *TTI);137 bool Change = FPM.runOnFunction(F, A);138 // Given that sandboxir::Context `Ctx` is defined at a pass-level scope, the139 // maps from LLVM IR to Sandbox IR may go stale as later passes remove LLVM IR140 // objects. To avoid issues caused by this clear the context's state.141 // NOTE: The alternative would be to define Ctx and FPM within runOnFunction()142 Ctx->clear();143 return Change;144}145