kazu created this revision.
kazu added reviewers: davidxl, mtrofin, wmi.
kazu added a project: LLVM.
Herald added subscribers: cfe-commits, rupprecht, MaskRay, hiraditya, mgorny.
Herald added a reviewer: jhenderson.
Herald added a project: clang.
This patch adds a utility called DumpAccumulator.
DumpAccumulator allows you to dump arbitrary text messages into a special
section called .llvm_dump. The linker then concatenates these messages into
the identically named section in the final executable.
This utility makes it easy to collect information from optimization
passes of interest in a build environment that caches compilation.
See llvm/include/llvm/Analysis/DumpAccumulator.h for usage.
The original implementation is from Mircea Trofin, and I generalized it.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D84473
Files:
clang/lib/CodeGen/BackendUtil.cpp
llvm/include/llvm/Analysis/DumpAccumulator.h
llvm/include/llvm/InitializePasses.h
llvm/lib/Analysis/CMakeLists.txt
llvm/lib/Analysis/DumpAccumulator.cpp
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/Passes/PassBuilder.cpp
llvm/lib/Passes/PassRegistry.def
llvm/test/Other/new-pm-defaults.ll
llvm/tools/llvm-readobj/ObjDumper.cpp
llvm/tools/llvm-readobj/ObjDumper.h
llvm/tools/llvm-readobj/llvm-readobj.cpp
Index: llvm/tools/llvm-readobj/llvm-readobj.cpp
===================================================================
--- llvm/tools/llvm-readobj/llvm-readobj.cpp
+++ llvm/tools/llvm-readobj/llvm-readobj.cpp
@@ -362,6 +362,10 @@
clEnumVal(GNU, "GNU readelf style")),
cl::init(LLVM));
+ // --llvm-dump
+ cl::opt<bool> LLVMDumpSection("llvm-dump", cl::desc("Print .llvm-dump"),
+ cl::init(false));
+
cl::extrahelp
HelpResponse("\nPass @FILE as argument to read options from FILE.\n");
} // namespace opts
@@ -487,6 +491,8 @@
Dumper->printSymbols(opts::Symbols, opts::DynamicSymbols);
if (!opts::StringDump.empty())
Dumper->printSectionsAsString(Obj, opts::StringDump);
+ if (opts::LLVMDumpSection)
+ Dumper->printLLVMDumpSection(Obj);
if (!opts::HexDump.empty())
Dumper->printSectionsAsHex(Obj, opts::HexDump);
if (opts::HashTable)
Index: llvm/tools/llvm-readobj/ObjDumper.h
===================================================================
--- llvm/tools/llvm-readobj/ObjDumper.h
+++ llvm/tools/llvm-readobj/ObjDumper.h
@@ -100,6 +100,7 @@
void printSectionsAsString(const object::ObjectFile *Obj,
ArrayRef<std::string> Sections);
+ void printLLVMDumpSection(const object::ObjectFile *Obj);
void printSectionsAsHex(const object::ObjectFile *Obj,
ArrayRef<std::string> Sections);
Index: llvm/tools/llvm-readobj/ObjDumper.cpp
===================================================================
--- llvm/tools/llvm-readobj/ObjDumper.cpp
+++ llvm/tools/llvm-readobj/ObjDumper.cpp
@@ -15,8 +15,10 @@
#include "Error.h"
#include "llvm-readobj.h"
#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Compression.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/LEB128.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
@@ -80,6 +82,45 @@
return Ret;
}
+void ObjDumper::printLLVMDumpSection(const object::ObjectFile *Obj) {
+ auto Sections = getSectionRefsByNameOrIndex(Obj, {".llvm_dump"});
+ if (Sections.size() != 1) {
+ reportWarning(createError(".llvm_dump section not found"),
+ Obj->getFileName());
+ return;
+ }
+ auto Section = Sections[0];
+ StringRef SectionContent =
+ unwrapOrError(Obj->getFileName(), Section.getContents());
+
+ StringRef Current = SectionContent;
+ unsigned Read = 0;
+ auto ReadNumber = [&]() {
+ uint64_t V =
+ decodeULEB128(reinterpret_cast<const uint8_t *>(Current.data()), &Read);
+ Current = Current.substr(Read);
+ return V;
+ };
+ while (Current.size() > 0) {
+ uint64_t UncompressedSize = ReadNumber();
+ std::unique_ptr<char[]> Uncompressed(new char[UncompressedSize]);
+ uint64_t CompressedSize = ReadNumber();
+ if (CompressedSize > Current.size()) {
+ reportWarning(
+ createError(
+ "Expecting a larger compressed buffer than available data"),
+ Obj->getFileName());
+ }
+ if (auto E =
+ zlib::uncompress(Current, Uncompressed.get(), UncompressedSize)) {
+ reportWarning(createError("Error decompressing"), Obj->getFileName());
+ }
+ Current = Current.substr(CompressedSize);
+ StringRef Message(Uncompressed.get(), UncompressedSize);
+ W.startLine() << Message << "\n";
+ }
+}
+
void ObjDumper::printSectionsAsString(const object::ObjectFile *Obj,
ArrayRef<std::string> Sections) {
bool First = true;
Index: llvm/test/Other/new-pm-defaults.ll
===================================================================
--- llvm/test/Other/new-pm-defaults.ll
+++ llvm/test/Other/new-pm-defaults.ll
@@ -92,6 +92,8 @@
; CHECK-O-NEXT: Starting llvm::Module pass manager run.
; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
; CHECK-O-NEXT: Starting llvm::Module pass manager run.
+; CHECK-O-NEXT: RequireAnalysisPass<llvm::DumpAccumulator, llvm::Module>
+; CHECK-O-NEXT: Running analysis: DumpAccumulator
; CHECK-O-NEXT: Running pass: ForceFunctionAttrsPass
; CHECK-EP-PIPELINE-START-NEXT: Running pass: NoOpModulePass
; CHECK-O-NEXT: Running pass: PassManager<{{.*}}Module{{.*}}>
Index: llvm/lib/Passes/PassRegistry.def
===================================================================
--- llvm/lib/Passes/PassRegistry.def
+++ llvm/lib/Passes/PassRegistry.def
@@ -28,6 +28,7 @@
MODULE_ANALYSIS("pass-instrumentation", PassInstrumentationAnalysis(PIC))
MODULE_ANALYSIS("asan-globals-md", ASanGlobalsMetadataAnalysis())
MODULE_ANALYSIS("inline-advisor", InlineAdvisorAnalysis())
+MODULE_ANALYSIS("dump-accumulator", DumpAccumulator())
#ifndef MODULE_ALIAS_ANALYSIS
#define MODULE_ALIAS_ANALYSIS(NAME, CREATE_PASS) \
Index: llvm/lib/Passes/PassBuilder.cpp
===================================================================
--- llvm/lib/Passes/PassBuilder.cpp
+++ llvm/lib/Passes/PassBuilder.cpp
@@ -31,6 +31,7 @@
#include "llvm/Analysis/DemandedBits.h"
#include "llvm/Analysis/DependenceAnalysis.h"
#include "llvm/Analysis/DominanceFrontier.h"
+#include "llvm/Analysis/DumpAccumulator.h"
#include "llvm/Analysis/FunctionPropertiesAnalysis.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/IVUsers.h"
@@ -255,6 +256,10 @@
cl::Hidden,
cl::desc("Enable inline deferral during PGO"));
+cl::opt<bool> EnableDumpAccumulator("enable-dump-accumulator", cl::init(true),
+ cl::Hidden,
+ cl::desc("Enable the dump accumulator."));
+
PipelineTuningOptions::PipelineTuningOptions() {
LoopInterleaving = true;
LoopVectorization = true;
@@ -1241,6 +1246,8 @@
ModulePassManager MPM(DebugLogging);
+ MPM.addPass(RequireAnalysisPass<DumpAccumulator, Module>());
+
// Force any function attributes we want the rest of the pipeline to observe.
MPM.addPass(ForceFunctionAttrsPass());
Index: llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
===================================================================
--- llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -29,6 +29,7 @@
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/DumpAccumulator.h"
#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/BinaryFormat/COFF.h"
@@ -106,6 +107,7 @@
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Compression.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MathExtras.h"
@@ -246,6 +248,7 @@
MachineFunctionPass::getAnalysisUsage(AU);
AU.addRequired<MachineOptimizationRemarkEmitterPass>();
AU.addRequired<GCModuleInfo>();
+ AU.addUsedIfAvailable<DumpAccumulatorWrapper>();
}
bool AsmPrinter::doInitialization(Module &M) {
@@ -1757,6 +1760,20 @@
}
}
+ if (auto *DumpAccumulatorAnalysis =
+ getAnalysisIfAvailable<DumpAccumulatorWrapper>()) {
+ auto *DS = OutStreamer->getContext().getELFSection(
+ ".llvm_dump", ELF::SHT_NOTE, ELF::SHF_STRINGS);
+ OutStreamer->SwitchSection(DS);
+ std::string &Out = DumpAccumulatorAnalysis->GetResult(M)->Message;
+ SmallVector<char, 128> Compressed;
+ Error E = zlib::compress(Out.c_str(), Compressed);
+ assert(!E);
+ OutStreamer->emitULEB128IntValue(Out.size());
+ OutStreamer->emitULEB128IntValue(Compressed.size());
+ OutStreamer->emitBytes({Compressed.data(), Compressed.size()});
+ }
+
// Allow the target to emit any magic that it wants at the end of the file,
// after everything else has gone out.
emitEndOfAsmFile(M);
Index: llvm/lib/Analysis/DumpAccumulator.cpp
===================================================================
--- /dev/null
+++ llvm/lib/Analysis/DumpAccumulator.cpp
@@ -0,0 +1,30 @@
+//===- DumpAccumulator.cpp - Dumping infrastructure -----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This implements feature and label extraction for offline supervised learning
+// of a IR to native size model.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/DumpAccumulator.h"
+#include "llvm/InitializePasses.h"
+
+using namespace llvm;
+
+AnalysisKey DumpAccumulator::Key;
+
+char DumpAccumulatorWrapper::ID = 0;
+INITIALIZE_PASS(DumpAccumulatorWrapper, "dumpaccumulator", "Dump Accumulator",
+ false, true)
+
+DumpAccumulatorWrapper::DumpAccumulatorWrapper(
+ std::function<DumpAccumulator::Result *(Module &M)> GetFFA)
+ : ImmutablePass(ID), GetFFA(GetFFA) {
+ initializeDumpAccumulatorWrapperPass(*PassRegistry::getPassRegistry());
+}
Index: llvm/lib/Analysis/CMakeLists.txt
===================================================================
--- llvm/lib/Analysis/CMakeLists.txt
+++ llvm/lib/Analysis/CMakeLists.txt
@@ -48,6 +48,7 @@
DomPrinter.cpp
DomTreeUpdater.cpp
DominanceFrontier.cpp
+ DumpAccumulator.cpp
EHPersonalities.cpp
FunctionPropertiesAnalysis.cpp
GlobalsModRef.cpp
Index: llvm/include/llvm/InitializePasses.h
===================================================================
--- llvm/include/llvm/InitializePasses.h
+++ llvm/include/llvm/InitializePasses.h
@@ -138,6 +138,7 @@
void initializeDomViewerPass(PassRegistry&);
void initializeDominanceFrontierWrapperPassPass(PassRegistry&);
void initializeDominatorTreeWrapperPassPass(PassRegistry&);
+void initializeDumpAccumulatorWrapperPass(PassRegistry &);
void initializeDwarfEHPreparePass(PassRegistry&);
void initializeEarlyCSELegacyPassPass(PassRegistry&);
void initializeEarlyCSEMemSSALegacyPassPass(PassRegistry&);
Index: llvm/include/llvm/Analysis/DumpAccumulator.h
===================================================================
--- /dev/null
+++ llvm/include/llvm/Analysis/DumpAccumulator.h
@@ -0,0 +1,97 @@
+//===- llvm/Analysis/DumpAccumulator.h - Dump Accumulator -------*- C++ -*-===//
+//
+// 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 contains the declarations for the dump accumulator.
+//
+// DumpAccumulator allows you to dump arbitrary text messages into a special
+// section called .llvm_dump. The linker then concatenates these messages into
+// the identically named section in the final executable.
+//
+// This utility makes it easy to collect information from optimization passes of
+// interest in a build environment that caches compilation.
+//
+// Suppose you wish to dump all occurrences of inlining. Then:
+//
+// Step 1: Build your compiler with the following modifications.
+//
+// Add:
+//
+// #include "llvm/Analysis/DumpAccumulator.h"
+//
+// Declare in the inlining pass:
+//
+// DumpAccumulator::Result *DAR = MAMProxy.getCachedResult<DumpAccumulator>(M);
+//
+// Add code like so that a message is accumulated every time inlining happens:
+//
+// if (DAR) {
+// DAR->Message += F.getName();
+// DAR->Message += ",";
+// DAR->Message += Callee.getName();
+// DAR->Message += "\n";
+// }
+//
+// Step 2: Build your testcase with:
+//
+// -mllvm -enable-dump-accumulator
+//
+// Note that ThinLTO is not supported yet.
+//
+// Step 3: Dump the messages like so:
+//
+// $ llvm-readobj --llvm-dump a.out
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_DUMPACCUMULATOR_H
+#define LLVM_ANALYSIS_DUMPACCUMULATOR_H
+
+#include "llvm/IR/PassManager.h"
+
+#include <string>
+
+namespace llvm {
+class DumpAccumulator : public AnalysisInfoMixin<DumpAccumulator> {
+public:
+ struct Result {
+ bool invalidate(Module &, const PreservedAnalyses &,
+ llvm::ModuleAnalysisManager::Invalidator &) {
+ return false;
+ }
+
+ Result() = default;
+ Result(const Result &) = delete;
+ Result(Result &&Other) = default;
+ ~Result() = default;
+
+ std::string Message;
+ };
+
+ DumpAccumulator() = default;
+
+ Result run(Module &M, ModuleAnalysisManager &MAM) { return {}; }
+
+private:
+ static AnalysisKey Key;
+ friend AnalysisInfoMixin<DumpAccumulator>;
+};
+
+class DumpAccumulatorWrapper : public ImmutablePass {
+ std::function<DumpAccumulator::Result *(Module &M)> GetFFA;
+
+public:
+ static char ID;
+ explicit DumpAccumulatorWrapper(
+ std::function<DumpAccumulator::Result *(Module &M)> GetFFA);
+ DumpAccumulatorWrapper() : ImmutablePass(ID){};
+ DumpAccumulator::Result *GetResult(Module &M) { return GetFFA(M); }
+};
+
+} // namespace llvm
+
+#endif // LLVM_ANALYSIS_DUMPACCUMULATOR_H
Index: clang/lib/CodeGen/BackendUtil.cpp
===================================================================
--- clang/lib/CodeGen/BackendUtil.cpp
+++ clang/lib/CodeGen/BackendUtil.cpp
@@ -18,6 +18,7 @@
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/DumpAccumulator.h"
#include "llvm/Analysis/StackSafetyAnalysis.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/TargetTransformInfo.h"
@@ -89,6 +90,8 @@
llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
#include "llvm/Support/Extension.def"
+extern cl::opt<bool> EnableDumpAccumulator;
+
namespace {
// Default filename used for profile generation.
@@ -1436,6 +1439,10 @@
NeedCodeGen = true;
CodeGenPasses.add(
createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
+ if (EnableDumpAccumulator)
+ CodeGenPasses.add(new DumpAccumulatorWrapper([&MAM](Module &M) {
+ return MAM.getCachedResult<DumpAccumulator>(M);
+ }));
if (!CodeGenOpts.SplitDwarfOutput.empty()) {
DwoOS = openOutputFile(CodeGenOpts.SplitDwarfOutput);
if (!DwoOS)
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