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//===- 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"
using namespace llvm;
#define DEBUG_TYPE "inline-replay"
ReplayInlineAdvisor::ReplayInlineAdvisor(
Module &M, FunctionAnalysisManager &FAM, LLVMContext &Context,
std::unique_ptr<InlineAdvisor> OriginalAdvisor, StringRef RemarksFile,
bool EmitRemarks)
: InlineAdvisor(M, FAM), OriginalAdvisor(std::move(OriginalAdvisor)),
HasReplayRemarks(false), EmitRemarks(EmitRemarks) {
auto BufferOrErr = MemoryBuffer::getFileOrSTDIN(RemarksFile);
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);
for (; !LineIt.is_at_eof(); ++LineIt) {
StringRef Line = *LineIt;
auto Pair = Line.split(" at callsite ");
auto Callee = Pair.first.split(" inlined into").first.rsplit(": ").second;
auto CallSite = Pair.second.split(";").first;
if (Callee.empty() || CallSite.empty())
continue;
std::string Combined = (Callee + CallSite).str();
InlineSitesFromRemarks.insert(Combined);
}
HasReplayRemarks = true;
}
std::unique_ptr<InlineAdvice> ReplayInlineAdvisor::getAdviceImpl(CallBase &CB) {
assert(HasReplayRemarks);
Function &Caller = *CB.getCaller();
auto &ORE = FAM.getResult<OptimizationRemarkEmitterAnalysis>(Caller);
if (InlineSitesFromRemarks.empty())
return std::make_unique<DefaultInlineAdvice>(this, CB, None, ORE,
EmitRemarks);
std::string CallSiteLoc = getCallSiteLocation(CB.getDebugLoc());
StringRef Callee = CB.getCalledFunction()->getName();
std::string Combined = (Callee + CallSiteLoc).str();
auto Iter = InlineSitesFromRemarks.find(Combined);
Optional<InlineCost> InlineRecommended = None;
if (Iter != InlineSitesFromRemarks.end()) {
InlineRecommended = llvm::InlineCost::getAlways("found in replay");
}
return std::make_unique<DefaultInlineAdvice>(this, CB, InlineRecommended, ORE,
EmitRemarks);
}
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