| //===- ReplayInlineAdvisor.cpp - Replay InlineAdvisor ---------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements ReplayInlineAdvisor that replays inline decisions based |
| // on previous inline remarks from optimization remark log. This is a best |
| // effort approach useful for testing compiler/source changes while holding |
| // inlining steady. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/ReplayInlineAdvisor.h" |
| #include "llvm/IR/DebugInfoMetadata.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/Support/LineIterator.h" |
| #include <memory> |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "replay-inline" |
| |
| ReplayInlineAdvisor::ReplayInlineAdvisor( |
| Module &M, FunctionAnalysisManager &FAM, LLVMContext &Context, |
| std::unique_ptr<InlineAdvisor> OriginalAdvisor, |
| const ReplayInlinerSettings &ReplaySettings, bool EmitRemarks) |
| : InlineAdvisor(M, FAM), OriginalAdvisor(std::move(OriginalAdvisor)), |
| HasReplayRemarks(false), ReplaySettings(ReplaySettings), |
| EmitRemarks(EmitRemarks) { |
| |
| auto BufferOrErr = MemoryBuffer::getFileOrSTDIN(ReplaySettings.ReplayFile); |
| std::error_code EC = BufferOrErr.getError(); |
| if (EC) { |
| Context.emitError("Could not open remarks file: " + EC.message()); |
| return; |
| } |
| |
| // Example for inline remarks to parse: |
| // main:3:1.1: '_Z3subii' inlined into 'main' at callsite sum:1 @ |
| // main:3:1.1; |
| // We use the callsite string after `at callsite` to replay inlining. |
| line_iterator LineIt(*BufferOrErr.get(), /*SkipBlanks=*/true); |
| const std::string PositiveRemark = "' inlined into '"; |
| const std::string NegativeRemark = "' will not be inlined into '"; |
| |
| for (; !LineIt.is_at_eof(); ++LineIt) { |
| StringRef Line = *LineIt; |
| auto Pair = Line.split(" at callsite "); |
| |
| bool IsPositiveRemark = true; |
| if (Pair.first.contains(NegativeRemark)) |
| IsPositiveRemark = false; |
| |
| auto CalleeCaller = |
| Pair.first.split(IsPositiveRemark ? PositiveRemark : NegativeRemark); |
| |
| StringRef Callee = CalleeCaller.first.rsplit(": '").second; |
| StringRef Caller = CalleeCaller.second.rsplit("'").first; |
| |
| auto CallSite = Pair.second.split(";").first; |
| |
| if (Callee.empty() || Caller.empty() || CallSite.empty()) { |
| Context.emitError("Invalid remark format: " + Line); |
| return; |
| } |
| |
| std::string Combined = (Callee + CallSite).str(); |
| InlineSitesFromRemarks[Combined] = IsPositiveRemark; |
| if (ReplaySettings.ReplayScope == ReplayInlinerSettings::Scope::Function) |
| CallersToReplay.insert(Caller); |
| } |
| |
| HasReplayRemarks = true; |
| } |
| |
| std::unique_ptr<InlineAdvisor> llvm::getReplayInlineAdvisor( |
| Module &M, FunctionAnalysisManager &FAM, LLVMContext &Context, |
| std::unique_ptr<InlineAdvisor> OriginalAdvisor, |
| const ReplayInlinerSettings &ReplaySettings, bool EmitRemarks) { |
| auto Advisor = std::make_unique<ReplayInlineAdvisor>( |
| M, FAM, Context, std::move(OriginalAdvisor), ReplaySettings, EmitRemarks); |
| if (!Advisor->areReplayRemarksLoaded()) |
| Advisor.reset(); |
| return Advisor; |
| } |
| |
| std::unique_ptr<InlineAdvice> ReplayInlineAdvisor::getAdviceImpl(CallBase &CB) { |
| assert(HasReplayRemarks); |
| |
| Function &Caller = *CB.getCaller(); |
| auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(Caller); |
| |
| // Decision not made by replay system |
| if (!hasInlineAdvice(*CB.getFunction())) { |
| // If there's a registered original advisor, return its decision |
| if (OriginalAdvisor) |
| return OriginalAdvisor->getAdvice(CB); |
| |
| // If no decision is made above, return non-decision |
| return {}; |
| } |
| |
| std::string CallSiteLoc = |
| formatCallSiteLocation(CB.getDebugLoc(), ReplaySettings.ReplayFormat); |
| StringRef Callee = CB.getCalledFunction()->getName(); |
| std::string Combined = (Callee + CallSiteLoc).str(); |
| |
| // Replay decision, if it has one |
| auto Iter = InlineSitesFromRemarks.find(Combined); |
| if (Iter != InlineSitesFromRemarks.end()) { |
| if (InlineSitesFromRemarks[Combined]) { |
| LLVM_DEBUG(dbgs() << "Replay Inliner: Inlined " << Callee << " @ " |
| << CallSiteLoc << "\n"); |
| return std::make_unique<DefaultInlineAdvice>( |
| this, CB, llvm::InlineCost::getAlways("previously inlined"), ORE, |
| EmitRemarks); |
| } else { |
| LLVM_DEBUG(dbgs() << "Replay Inliner: Not Inlined " << Callee << " @ " |
| << CallSiteLoc << "\n"); |
| // A negative inline is conveyed by "None" Optional<InlineCost> |
| return std::make_unique<DefaultInlineAdvice>(this, CB, None, ORE, |
| EmitRemarks); |
| } |
| } |
| |
| // Fallback decisions |
| if (ReplaySettings.ReplayFallback == |
| ReplayInlinerSettings::Fallback::AlwaysInline) |
| return std::make_unique<DefaultInlineAdvice>( |
| this, CB, llvm::InlineCost::getAlways("AlwaysInline Fallback"), ORE, |
| EmitRemarks); |
| else if (ReplaySettings.ReplayFallback == |
| ReplayInlinerSettings::Fallback::NeverInline) |
| // A negative inline is conveyed by "None" Optional<InlineCost> |
| return std::make_unique<DefaultInlineAdvice>(this, CB, None, ORE, |
| EmitRemarks); |
| else { |
| assert(ReplaySettings.ReplayFallback == |
| ReplayInlinerSettings::Fallback::Original); |
| // If there's a registered original advisor, return its decision |
| if (OriginalAdvisor) |
| return OriginalAdvisor->getAdvice(CB); |
| } |
| |
| // If no decision is made above, return non-decision |
| return {}; |
| } |