[llvm] [ctx_prof] Make the profile output analyzable by llvm-bcanalyzer (PR #99563)
Mircea Trofin via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 23 05:58:57 PDT 2024
https://github.com/mtrofin updated https://github.com/llvm/llvm-project/pull/99563
>From f62fd50c4738bf2e952ae7e9a02fd2e44b8386be Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Thu, 18 Jul 2024 13:46:57 -0700
Subject: [PATCH 1/2] [ctx_prof] Make the profile output analyzable by
llvm-bcanalyzer
This requires output-ing a "Magic" 4-byte header. We also emit a
block info block, to describe our blocks and records. The output
of `llvm-bcanalyzer` would look like:
```
<BLOCKINFO_BLOCK/>
<Metadata NumWords=17 BlockCodeSize=2>
<Version op0=1/>
<Context NumWords=13 BlockCodeSize=2>
<GUID op0=2/>
<Counters op0=1 op1=2 op2=3/>
```
Instead of having `Unknown` for block and record IDs.
---
.../llvm/ProfileData/PGOCtxProfReader.h | 7 +++-
.../llvm/ProfileData/PGOCtxProfWriter.h | 12 ++----
llvm/lib/ProfileData/PGOCtxProfReader.cpp | 13 ++++++
llvm/lib/ProfileData/PGOCtxProfWriter.cpp | 34 +++++++++++++++
.../PGOCtxProfReaderWriterTest.cpp | 41 +++++++++++--------
5 files changed, 79 insertions(+), 28 deletions(-)
diff --git a/llvm/include/llvm/ProfileData/PGOCtxProfReader.h b/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
index a19b3f51d642d..28f05e9073a8a 100644
--- a/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
+++ b/llvm/include/llvm/ProfileData/PGOCtxProfReader.h
@@ -73,7 +73,8 @@ class PGOContextualProfile final {
};
class PGOCtxProfileReader final {
- BitstreamCursor &Cursor;
+ StringRef Magic;
+ BitstreamCursor Cursor;
Expected<BitstreamEntry> advance();
Error readMetadata();
Error wrongValue(const Twine &);
@@ -84,7 +85,9 @@ class PGOCtxProfileReader final {
bool canReadContext();
public:
- PGOCtxProfileReader(BitstreamCursor &Cursor) : Cursor(Cursor) {}
+ PGOCtxProfileReader(StringRef Buffer)
+ : Magic(Buffer.substr(0, PGOCtxProfileWriter::ContainerMagic.size())),
+ Cursor(Buffer.substr(PGOCtxProfileWriter::ContainerMagic.size())) {}
Expected<std::map<GlobalValue::GUID, PGOContextualProfile>> loadContexts();
};
diff --git a/llvm/include/llvm/ProfileData/PGOCtxProfWriter.h b/llvm/include/llvm/ProfileData/PGOCtxProfWriter.h
index ecee7a2cfb539..db9a0fd77f835 100644
--- a/llvm/include/llvm/ProfileData/PGOCtxProfWriter.h
+++ b/llvm/include/llvm/ProfileData/PGOCtxProfWriter.h
@@ -13,6 +13,7 @@
#ifndef LLVM_PROFILEDATA_PGOCTXPROFWRITER_H_
#define LLVM_PROFILEDATA_PGOCTXPROFWRITER_H_
+#include "llvm/ADT/StringExtras.h"
#include "llvm/Bitstream/BitCodeEnums.h"
#include "llvm/Bitstream/BitstreamWriter.h"
#include "llvm/ProfileData/CtxInstrContextNode.h"
@@ -68,15 +69,7 @@ class PGOCtxProfileWriter final {
public:
PGOCtxProfileWriter(raw_ostream &Out,
- std::optional<unsigned> VersionOverride = std::nullopt)
- : Writer(Out, 0) {
- Writer.EnterSubblock(PGOCtxProfileBlockIDs::ProfileMetadataBlockID,
- CodeLen);
- const auto Version = VersionOverride ? *VersionOverride : CurrentVersion;
- Writer.EmitRecord(PGOCtxProfileRecords::Version,
- SmallVector<unsigned, 1>({Version}));
- }
-
+ std::optional<unsigned> VersionOverride = std::nullopt);
~PGOCtxProfileWriter() { Writer.ExitBlock(); }
void write(const ctx_profile::ContextNode &);
@@ -85,6 +78,7 @@ class PGOCtxProfileWriter final {
static constexpr unsigned CodeLen = 2;
static constexpr uint32_t CurrentVersion = 1;
static constexpr unsigned VBREncodingBits = 6;
+ static constexpr StringRef ContainerMagic = "CTXP";
};
} // namespace llvm
diff --git a/llvm/lib/ProfileData/PGOCtxProfReader.cpp b/llvm/lib/ProfileData/PGOCtxProfReader.cpp
index 1b42d8c765f2d..6b932b3ea02b4 100644
--- a/llvm/lib/ProfileData/PGOCtxProfReader.cpp
+++ b/llvm/lib/ProfileData/PGOCtxProfReader.cpp
@@ -12,6 +12,7 @@
//===----------------------------------------------------------------------===//
#include "llvm/ProfileData/PGOCtxProfReader.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/Bitstream/BitCodeEnums.h"
#include "llvm/Bitstream/BitstreamReader.h"
#include "llvm/ProfileData/InstrProf.h"
@@ -139,6 +140,18 @@ PGOCtxProfileReader::readContext(bool ExpectIndex) {
}
Error PGOCtxProfileReader::readMetadata() {
+ if (Magic.size() < PGOCtxProfileWriter::ContainerMagic.size() ||
+ Magic != PGOCtxProfileWriter::ContainerMagic)
+ return make_error<InstrProfError>(instrprof_error::invalid_prof,
+ "Invalid magic");
+
+ BitstreamEntry Entry;
+ RET_ON_ERR(Cursor.advance().moveInto(Entry));
+ if (Entry.Kind != BitstreamEntry::SubBlock ||
+ Entry.ID != bitc::BLOCKINFO_BLOCK_ID)
+ return unsupported("Expected Block ID");
+ RET_ON_ERR(Cursor.SkipBlock());
+
EXPECT_OR_RET(Blk, advance());
if (Blk->Kind != BitstreamEntry::SubBlock)
return unsupported("Expected Version record");
diff --git a/llvm/lib/ProfileData/PGOCtxProfWriter.cpp b/llvm/lib/ProfileData/PGOCtxProfWriter.cpp
index 5081797564469..74cd8763cc769 100644
--- a/llvm/lib/ProfileData/PGOCtxProfWriter.cpp
+++ b/llvm/lib/ProfileData/PGOCtxProfWriter.cpp
@@ -16,6 +16,40 @@
using namespace llvm;
using namespace llvm::ctx_profile;
+PGOCtxProfileWriter::PGOCtxProfileWriter(
+ raw_ostream &Out, std::optional<unsigned> VersionOverride)
+ : Writer(Out, 0) {
+ static_assert(ContainerMagic.size() == 4);
+ Out.write(ContainerMagic.data(), ContainerMagic.size());
+ Writer.EnterBlockInfoBlock();
+ {
+ auto DescribeBlock = [&](unsigned ID, StringRef Name) {
+ Writer.EmitRecord(bitc::BLOCKINFO_CODE_SETBID,
+ SmallVector<unsigned, 1>{ID});
+ Writer.EmitRecord(bitc::BLOCKINFO_CODE_BLOCKNAME,
+ llvm::arrayRefFromStringRef(Name));
+ };
+ SmallVector<uint64_t, 16> Data;
+ auto DescribeRecord = [&](unsigned RecordID, StringRef Name) {
+ Data.clear();
+ Data.push_back(RecordID);
+ llvm::append_range(Data, Name);
+ Writer.EmitRecord(bitc::BLOCKINFO_CODE_SETRECORDNAME, Data);
+ };
+ DescribeBlock(PGOCtxProfileBlockIDs::ProfileMetadataBlockID, "Metadata");
+ DescribeRecord(PGOCtxProfileRecords::Version, "Version");
+ DescribeBlock(PGOCtxProfileBlockIDs::ContextNodeBlockID, "Context");
+ DescribeRecord(PGOCtxProfileRecords::Guid, "GUID");
+ DescribeRecord(PGOCtxProfileRecords::CalleeIndex, "CalleeIndex");
+ DescribeRecord(PGOCtxProfileRecords::Counters, "Counters");
+ }
+ Writer.ExitBlock();
+ Writer.EnterSubblock(PGOCtxProfileBlockIDs::ProfileMetadataBlockID, CodeLen);
+ const auto Version = VersionOverride ? *VersionOverride : CurrentVersion;
+ Writer.EmitRecord(PGOCtxProfileRecords::Version,
+ SmallVector<unsigned, 1>({Version}));
+}
+
void PGOCtxProfileWriter::writeCounters(const ContextNode &Node) {
Writer.EmitCode(bitc::UNABBREV_RECORD);
Writer.EmitVBR(PGOCtxProfileRecords::Counters, VBREncodingBits);
diff --git a/llvm/unittests/ProfileData/PGOCtxProfReaderWriterTest.cpp b/llvm/unittests/ProfileData/PGOCtxProfReaderWriterTest.cpp
index 6c6798ded00b5..476f293780d84 100644
--- a/llvm/unittests/ProfileData/PGOCtxProfReaderWriterTest.cpp
+++ b/llvm/unittests/ProfileData/PGOCtxProfReaderWriterTest.cpp
@@ -6,7 +6,7 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/Bitstream/BitstreamReader.h"
+#include "llvm/Bitcode/BitcodeAnalyzer.h"
#include "llvm/ProfileData/CtxInstrContextNode.h"
#include "llvm/ProfileData/PGOCtxProfReader.h"
#include "llvm/ProfileData/PGOCtxProfWriter.h"
@@ -106,8 +106,20 @@ TEST_F(PGOCtxProfRWTest, RoundTrip) {
MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+
+ // Check it's analyzable by the BCAnalyzer
+ BitcodeAnalyzer BA((*MB)->getBuffer());
+ std::string AnalyzerDump;
+ raw_string_ostream OS(AnalyzerDump);
+ BCDumpOptions Opts(OS);
+
+ // As in, expect no error.
+ EXPECT_FALSE(BA.analyze(Opts));
+ EXPECT_TRUE(AnalyzerDump.find("<Metadata BlockID") != std::string::npos);
+ EXPECT_TRUE(AnalyzerDump.find("<Context BlockID") != std::string::npos);
+ EXPECT_TRUE(AnalyzerDump.find("<CalleeIndex codeid") != std::string::npos);
+
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
ASSERT_TRUE(!!Expected);
auto &Ctxes = *Expected;
@@ -143,8 +155,7 @@ TEST_F(PGOCtxProfRWTest, InvalidCounters) {
auto MB = MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
@@ -152,16 +163,14 @@ TEST_F(PGOCtxProfRWTest, InvalidCounters) {
}
TEST_F(PGOCtxProfRWTest, Empty) {
- BitstreamCursor Cursor("");
- PGOCtxProfileReader Reader(Cursor);
+ PGOCtxProfileReader Reader("");
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
}
TEST_F(PGOCtxProfRWTest, Invalid) {
- BitstreamCursor Cursor("Surely this is not valid");
- PGOCtxProfileReader Reader(Cursor);
+ PGOCtxProfileReader Reader("Surely this is not valid");
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
@@ -182,8 +191,8 @@ TEST_F(PGOCtxProfRWTest, ValidButEmpty) {
auto MB = MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
EXPECT_TRUE(!!Expected);
EXPECT_TRUE(Expected->empty());
@@ -204,8 +213,8 @@ TEST_F(PGOCtxProfRWTest, WrongVersion) {
auto MB = MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
@@ -228,8 +237,7 @@ TEST_F(PGOCtxProfRWTest, DuplicateRoots) {
auto MB = MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
@@ -255,8 +263,7 @@ TEST_F(PGOCtxProfRWTest, DuplicateTargets) {
auto MB = MemoryBuffer::getFile(ProfileFile.path());
ASSERT_TRUE(!!MB);
ASSERT_NE(*MB, nullptr);
- BitstreamCursor Cursor((*MB)->getBuffer());
- PGOCtxProfileReader Reader(Cursor);
+ PGOCtxProfileReader Reader((*MB)->getBuffer());
auto Expected = Reader.loadContexts();
EXPECT_FALSE(Expected);
consumeError(Expected.takeError());
>From 356339e8a2892798e8b022ab9a69d5229ae8f7df Mon Sep 17 00:00:00 2001
From: Mircea Trofin <mtrofin at google.com>
Date: Tue, 23 Jul 2024 05:24:48 -0700
Subject: [PATCH 2/2] comment
---
llvm/lib/ProfileData/PGOCtxProfReader.cpp | 2 ++
1 file changed, 2 insertions(+)
diff --git a/llvm/lib/ProfileData/PGOCtxProfReader.cpp b/llvm/lib/ProfileData/PGOCtxProfReader.cpp
index 6b932b3ea02b4..0a0e7db457fa8 100644
--- a/llvm/lib/ProfileData/PGOCtxProfReader.cpp
+++ b/llvm/lib/ProfileData/PGOCtxProfReader.cpp
@@ -150,6 +150,8 @@ Error PGOCtxProfileReader::readMetadata() {
if (Entry.Kind != BitstreamEntry::SubBlock ||
Entry.ID != bitc::BLOCKINFO_BLOCK_ID)
return unsupported("Expected Block ID");
+ // We don't need the blockinfo to read the rest, it's metadata usable for e.g.
+ // llvm-bcanalyzer.
RET_ON_ERR(Cursor.SkipBlock());
EXPECT_OR_RET(Blk, advance());
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