[llvm] [PGO] Add support for writing previous indexed format (PR #84505)
Teresa Johnson via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 8 07:59:21 PST 2024
https://github.com/teresajohnson created https://github.com/llvm/llvm-project/pull/84505
Enable temporary support to ease use of new llvm-profdata with slightly
older indexed profiles after 16e74fd48988ac95551d0f64e1b36f78a82a89a2,
which bumped the indexed format for type profiling.
>From 35ac97ec545310b2a55a00c736790309c94f931f Mon Sep 17 00:00:00 2001
From: Teresa Johnson <tejohnson at google.com>
Date: Fri, 8 Mar 2024 07:56:01 -0800
Subject: [PATCH] [PGO] Add support for writing previous indexed format
Enable temporary support to ease use of new llvm-profdata with slightly
older indexed profiles after 16e74fd48988ac95551d0f64e1b36f78a82a89a2,
which bumped the indexed format for type profiling.
---
.../llvm/ProfileData/InstrProfWriter.h | 10 +-
llvm/lib/ProfileData/InstrProfWriter.cpp | 107 +++++++++++-------
.../tools/llvm-profdata/profile-version.test | 9 ++
llvm/tools/llvm-profdata/llvm-profdata.cpp | 13 ++-
4 files changed, 97 insertions(+), 42 deletions(-)
create mode 100644 llvm/test/tools/llvm-profdata/profile-version.test
diff --git a/llvm/include/llvm/ProfileData/InstrProfWriter.h b/llvm/include/llvm/ProfileData/InstrProfWriter.h
index 7a806fd7fcf345..baa8b3aa1d3d1f 100644
--- a/llvm/include/llvm/ProfileData/InstrProfWriter.h
+++ b/llvm/include/llvm/ProfileData/InstrProfWriter.h
@@ -68,10 +68,18 @@ class InstrProfWriter {
// Use raw pointer here for the incomplete type object.
InstrProfRecordWriterTrait *InfoObj;
+ // Temporary support for writing the previous version of the format, to enable
+ // some forward compaitibility. Currently this suppresses the writing of the
+ // new vtable names section and header fields.
+ // TODO: Consider enabling this with future version changes as well, to ease
+ // deployment of newer versions of llvm-profdata.
+ bool WritePrevVersion = false;
+
public:
InstrProfWriter(bool Sparse = false,
uint64_t TemporalProfTraceReservoirSize = 0,
- uint64_t MaxTemporalProfTraceLength = 0);
+ uint64_t MaxTemporalProfTraceLength = 0,
+ bool WritePrevVersion = true);
~InstrProfWriter();
StringMap<ProfilingData> &getProfileData() { return FunctionData; }
diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 3e0a0e0d70116d..9eeb00d99f5dde 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -181,10 +181,12 @@ class InstrProfRecordWriterTrait {
InstrProfWriter::InstrProfWriter(bool Sparse,
uint64_t TemporalProfTraceReservoirSize,
- uint64_t MaxTemporalProfTraceLength)
+ uint64_t MaxTemporalProfTraceLength,
+ bool WritePrevVersion)
: Sparse(Sparse), MaxTemporalProfTraceLength(MaxTemporalProfTraceLength),
TemporalProfTraceReservoirSize(TemporalProfTraceReservoirSize),
- InfoObj(new InstrProfRecordWriterTrait()) {}
+ InfoObj(new InstrProfRecordWriterTrait()),
+ WritePrevVersion(WritePrevVersion) {}
InstrProfWriter::~InstrProfWriter() { delete InfoObj; }
@@ -433,6 +435,8 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
IndexedInstrProf::Header Header;
Header.Magic = IndexedInstrProf::Magic;
Header.Version = IndexedInstrProf::ProfVersion::CurrentVersion;
+ if (WritePrevVersion)
+ Header.Version--;
if (static_cast<bool>(ProfileKind & InstrProfKind::IRInstrumentation))
Header.Version |= VARIANT_MASK_IR_PROF;
if (static_cast<bool>(ProfileKind & InstrProfKind::ContextSensitive))
@@ -484,7 +488,8 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
OS.write(0);
uint64_t VTableNamesOffset = OS.tell();
- OS.write(0);
+ if (!WritePrevVersion)
+ OS.write(0);
// Reserve space to write profile summary data.
uint32_t NumEntries = ProfileSummaryBuilder::DefaultCutoffs.size();
@@ -608,27 +613,29 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
uint64_t VTableNamesSectionStart = OS.tell();
- // Use a dummy (and uncompressed) string as compressed vtable names and get
- // the necessary profile format change in place for version 12.
- // TODO: Store the list of vtable names in InstrProfWriter and use the
- // real compressed name.
- std::string CompressedVTableNames = "VTableNames";
+ if (!WritePrevVersion) {
+ // Use a dummy (and uncompressed) string as compressed vtable names and get
+ // the necessary profile format change in place for version 12.
+ // TODO: Store the list of vtable names in InstrProfWriter and use the
+ // real compressed name.
+ std::string CompressedVTableNames = "VTableNames";
- uint64_t CompressedStringLen = CompressedVTableNames.length();
+ uint64_t CompressedStringLen = CompressedVTableNames.length();
- // Record the length of compressed string.
- OS.write(CompressedStringLen);
+ // Record the length of compressed string.
+ OS.write(CompressedStringLen);
- // Write the chars in compressed strings.
- for (auto &c : CompressedVTableNames)
- OS.writeByte(static_cast<uint8_t>(c));
+ // Write the chars in compressed strings.
+ for (auto &c : CompressedVTableNames)
+ OS.writeByte(static_cast<uint8_t>(c));
- // Pad up to a multiple of 8.
- // InstrProfReader would read bytes according to 'CompressedStringLen'.
- uint64_t PaddedLength = alignTo(CompressedStringLen, 8);
+ // Pad up to a multiple of 8.
+ // InstrProfReader would read bytes according to 'CompressedStringLen'.
+ uint64_t PaddedLength = alignTo(CompressedStringLen, 8);
- for (uint64_t K = CompressedStringLen; K < PaddedLength; K++) {
- OS.writeByte(0);
+ for (uint64_t K = CompressedStringLen; K < PaddedLength; K++) {
+ OS.writeByte(0);
+ }
}
uint64_t TemporalProfTracesSectionStart = 0;
@@ -662,26 +669,48 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
}
InfoObj->CSSummaryBuilder = nullptr;
- // Now do the final patch:
- PatchItem PatchItems[] = {
- // Patch the Header.HashOffset field.
- {HashTableStartFieldOffset, &HashTableStart, 1},
- // Patch the Header.MemProfOffset (=0 for profiles without MemProf
- // data).
- {MemProfSectionOffset, &MemProfSectionStart, 1},
- // Patch the Header.BinaryIdSectionOffset.
- {BinaryIdSectionOffset, &BinaryIdSectionStart, 1},
- // Patch the Header.TemporalProfTracesOffset (=0 for profiles without
- // traces).
- {TemporalProfTracesOffset, &TemporalProfTracesSectionStart, 1},
- {VTableNamesOffset, &VTableNamesSectionStart, 1},
- // Patch the summary data.
- {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()),
- (int)(SummarySize / sizeof(uint64_t))},
- {CSSummaryOffset, reinterpret_cast<uint64_t *>(TheCSSummary.get()),
- (int)CSSummarySize}};
-
- OS.patch(PatchItems, std::size(PatchItems));
+ if (!WritePrevVersion) {
+ // Now do the final patch:
+ PatchItem PatchItems[] = {
+ // Patch the Header.HashOffset field.
+ {HashTableStartFieldOffset, &HashTableStart, 1},
+ // Patch the Header.MemProfOffset (=0 for profiles without MemProf
+ // data).
+ {MemProfSectionOffset, &MemProfSectionStart, 1},
+ // Patch the Header.BinaryIdSectionOffset.
+ {BinaryIdSectionOffset, &BinaryIdSectionStart, 1},
+ // Patch the Header.TemporalProfTracesOffset (=0 for profiles without
+ // traces).
+ {TemporalProfTracesOffset, &TemporalProfTracesSectionStart, 1},
+ {VTableNamesOffset, &VTableNamesSectionStart, 1},
+ // Patch the summary data.
+ {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()),
+ (int)(SummarySize / sizeof(uint64_t))},
+ {CSSummaryOffset, reinterpret_cast<uint64_t *>(TheCSSummary.get()),
+ (int)CSSummarySize}};
+
+ OS.patch(PatchItems, std::size(PatchItems));
+ } else {
+ // Now do the final patch:
+ PatchItem PatchItems[] = {
+ // Patch the Header.HashOffset field.
+ {HashTableStartFieldOffset, &HashTableStart, 1},
+ // Patch the Header.MemProfOffset (=0 for profiles without MemProf
+ // data).
+ {MemProfSectionOffset, &MemProfSectionStart, 1},
+ // Patch the Header.BinaryIdSectionOffset.
+ {BinaryIdSectionOffset, &BinaryIdSectionStart, 1},
+ // Patch the Header.TemporalProfTracesOffset (=0 for profiles without
+ // traces).
+ {TemporalProfTracesOffset, &TemporalProfTracesSectionStart, 1},
+ // Patch the summary data.
+ {SummaryOffset, reinterpret_cast<uint64_t *>(TheSummary.get()),
+ (int)(SummarySize / sizeof(uint64_t))},
+ {CSSummaryOffset, reinterpret_cast<uint64_t *>(TheCSSummary.get()),
+ (int)CSSummarySize}};
+
+ OS.patch(PatchItems, std::size(PatchItems));
+ }
for (const auto &I : FunctionData)
for (const auto &F : I.getValue())
diff --git a/llvm/test/tools/llvm-profdata/profile-version.test b/llvm/test/tools/llvm-profdata/profile-version.test
new file mode 100644
index 00000000000000..cb68a648d5e5aa
--- /dev/null
+++ b/llvm/test/tools/llvm-profdata/profile-version.test
@@ -0,0 +1,9 @@
+Test the profile version.
+
+RUN: llvm-profdata merge -o %t.profdata %p/Inputs/basic.proftext
+RUN: llvm-profdata show --profile-version %t.profdata | FileCheck %s
+CHECK: Profile version: 12
+
+RUN: llvm-profdata merge -o %t.prev.profdata %p/Inputs/basic.proftext --write-prev-version
+RUN: llvm-profdata show --profile-version %t.prev.profdata | FileCheck %s --check-prefix=PREV
+PREV: Profile version: 11
diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
index 8400b0769944cf..327c6cf66541db 100644
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -291,6 +291,15 @@ cl::opt<bool> DropProfileSymbolList(
cl::desc("Drop the profile symbol list when merging AutoFDO profiles "
"(only meaningful for -sample)"));
+// Temporary support for writing the previous version of the format, to enable
+// some forward compaitibility.
+// TODO: Consider enabling this with future version changes as well, to ease
+// deployment of newer versions of llvm-profdata.
+cl::opt<bool> DoWritePrevVersion(
+ "write-prev-version", cl::init(false), cl::Hidden,
+ cl::desc("Write the previous version of indexed format, to enable "
+ "some forward compatibility."));
+
// Options specific to overlap subcommand.
cl::opt<std::string> BaseFilename(cl::Positional, cl::Required,
cl::desc("<base profile file>"),
@@ -579,8 +588,8 @@ struct WriterContext {
WriterContext(bool IsSparse, std::mutex &ErrLock,
SmallSet<instrprof_error, 4> &WriterErrorCodes,
uint64_t ReservoirSize = 0, uint64_t MaxTraceLength = 0)
- : Writer(IsSparse, ReservoirSize, MaxTraceLength), ErrLock(ErrLock),
- WriterErrorCodes(WriterErrorCodes) {}
+ : Writer(IsSparse, ReservoirSize, MaxTraceLength, DoWritePrevVersion),
+ ErrLock(ErrLock), WriterErrorCodes(WriterErrorCodes) {}
};
/// Computer the overlap b/w profile BaseFilename and TestFileName,
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