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[NFC][PGO] Use constants rather than free strings for metadata labels (#145721)

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This commit is contained in:
Mircea Trofin
2025-06-25 16:20:10 -07:00
committed by GitHub
parent 00f6d6ab66
commit 82cbd68504
8 changed files with 48 additions and 26 deletions
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7
llvm/include/llvm/IR/ProfDataUtils.h
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@@ -21,6 +21,13 @@
#include "llvm/Support/Compiler.h"
namespace llvm {
struct MDProfLabels {
static const char *BranchWeights;
static const char *ValueProfile;
static const char *FunctionEntryCount;
static const char *SyntheticFunctionEntryCount;
static const char *ExpectedBranchWeights;
};
/// Checks if an Instruction has MD_prof Metadata
LLVM_ABI bool hasProfMD(const Instruction &I);

2
llvm/lib/Bitcode/Reader/BitcodeReader.cpp
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@@ -7031,7 +7031,7 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
MDString *MDS = cast<MDString>(MD->getOperand(0));
StringRef ProfName = MDS->getString();
// Check consistency of !prof branch_weights metadata.
if (ProfName != "branch_weights")
if (ProfName != MDProfLabels::BranchWeights)
continue;
unsigned ExpectedNumOperands = 0;
if (BranchInst *BI = dyn_cast<BranchInst>(&I))

8
llvm/lib/IR/Function.cpp
View File

@@ -37,6 +37,7 @@
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/ProfDataUtils.h"
#include "llvm/IR/SymbolTableListTraits.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
@@ -1115,7 +1116,7 @@ std::optional<ProfileCount> Function::getEntryCount(bool AllowSynthetic) const {
MDNode *MD = getMetadata(LLVMContext::MD_prof);
if (MD && MD->getOperand(0))
if (MDString *MDS = dyn_cast<MDString>(MD->getOperand(0))) {
if (MDS->getString() == "function_entry_count") {
if (MDS->getString() == MDProfLabels::FunctionEntryCount) {
ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(1));
uint64_t Count = CI->getValue().getZExtValue();
// A value of -1 is used for SamplePGO when there were no samples.
@@ -1124,7 +1125,8 @@ std::optional<ProfileCount> Function::getEntryCount(bool AllowSynthetic) const {
return std::nullopt;
return ProfileCount(Count, PCT_Real);
} else if (AllowSynthetic &&
MDS->getString() == "synthetic_function_entry_count") {
MDS->getString() ==
MDProfLabels::SyntheticFunctionEntryCount) {
ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(1));
uint64_t Count = CI->getValue().getZExtValue();
return ProfileCount(Count, PCT_Synthetic);
@@ -1137,7 +1139,7 @@ DenseSet<GlobalValue::GUID> Function::getImportGUIDs() const {
DenseSet<GlobalValue::GUID> R;
if (MDNode *MD = getMetadata(LLVMContext::MD_prof))
if (MDString *MDS = dyn_cast<MDString>(MD->getOperand(0)))
if (MDS->getString() == "function_entry_count")
if (MDS->getString() == MDProfLabels::FunctionEntryCount)
for (unsigned i = 2; i < MD->getNumOperands(); i++)
R.insert(mdconst::extract<ConstantInt>(MD->getOperand(i))
->getValue()

9
llvm/lib/IR/MDBuilder.cpp
View File

@@ -15,6 +15,7 @@
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/ProfDataUtils.h"
using namespace llvm;
MDString *MDBuilder::createString(StringRef Str) {
@@ -55,9 +56,9 @@ MDNode *MDBuilder::createBranchWeights(ArrayRef<uint32_t> Weights,
unsigned int Offset = IsExpected ? 2 : 1;
SmallVector<Metadata *, 4> Vals(Weights.size() + Offset);
Vals[0] = createString("branch_weights");
Vals[0] = createString(MDProfLabels::BranchWeights);
if (IsExpected)
Vals[1] = createString("expected");
Vals[1] = createString(MDProfLabels::ExpectedBranchWeights);
Type *Int32Ty = Type::getInt32Ty(Context);
for (unsigned i = 0, e = Weights.size(); i != e; ++i)
@@ -74,9 +75,9 @@ MDNode *MDBuilder::createFunctionEntryCount(
Type *Int64Ty = Type::getInt64Ty(Context);
SmallVector<Metadata *, 8> Ops;
if (Synthetic)
Ops.push_back(createString("synthetic_function_entry_count"));
Ops.push_back(createString(MDProfLabels::SyntheticFunctionEntryCount));
else
Ops.push_back(createString("function_entry_count"));
Ops.push_back(createString(MDProfLabels::FunctionEntryCount));
Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
if (Imports) {
SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());

5
llvm/lib/IR/Metadata.cpp
View File

@@ -1202,14 +1202,15 @@ MDNode *MDNode::mergeDirectCallProfMetadata(MDNode *A, MDNode *B,
"first operand should be a non-null MDString");
StringRef AProfName = AMDS->getString();
StringRef BProfName = BMDS->getString();
if (AProfName == "branch_weights" && BProfName == "branch_weights") {
if (AProfName == MDProfLabels::BranchWeights &&
BProfName == MDProfLabels::BranchWeights) {
ConstantInt *AInstrWeight = mdconst::dyn_extract<ConstantInt>(
A->getOperand(getBranchWeightOffset(A)));
ConstantInt *BInstrWeight = mdconst::dyn_extract<ConstantInt>(
B->getOperand(getBranchWeightOffset(B)));
assert(AInstrWeight && BInstrWeight && "verified by LLVM verifier");
return MDNode::get(Ctx,
{MDHelper.createString("branch_weights"),
{MDHelper.createString(MDProfLabels::BranchWeights),
MDHelper.createConstant(ConstantInt::get(
Type::getInt64Ty(Ctx),
SaturatingAdd(AInstrWeight->getZExtValue(),

28
llvm/lib/IR/ProfDataUtils.cpp
View File

@@ -88,16 +88,23 @@ static void extractFromBranchWeightMD(const MDNode *ProfileData,
namespace llvm {
const char *MDProfLabels::BranchWeights = "branch_weights";
const char *MDProfLabels::ExpectedBranchWeights = "expected";
const char *MDProfLabels::ValueProfile = "VP";
const char *MDProfLabels::FunctionEntryCount = "function_entry_count";
const char *MDProfLabels::SyntheticFunctionEntryCount =
"synthetic_function_entry_count";
bool hasProfMD(const Instruction &I) {
return I.hasMetadata(LLVMContext::MD_prof);
}
bool isBranchWeightMD(const MDNode *ProfileData) {
return isTargetMD(ProfileData, "branch_weights", MinBWOps);
return isTargetMD(ProfileData, MDProfLabels::BranchWeights, MinBWOps);
}
static bool isValueProfileMD(const MDNode *ProfileData) {
return isTargetMD(ProfileData, "VP", MinVPOps);
return isTargetMD(ProfileData, MDProfLabels::ValueProfile, MinVPOps);
}
bool hasBranchWeightMD(const Instruction &I) {
@@ -131,7 +138,8 @@ bool hasBranchWeightOrigin(const MDNode *ProfileData) {
// NOTE: if we ever have more types of branch weight provenance,
// we need to check the string value is "expected". For now, we
// supply a more generic API, and avoid the spurious comparisons.
assert(ProfDataName == nullptr || ProfDataName->getString() == "expected");
assert(ProfDataName == nullptr ||
ProfDataName->getString() == MDProfLabels::ExpectedBranchWeights);
return ProfDataName != nullptr;
}
@@ -210,7 +218,7 @@ bool extractProfTotalWeight(const MDNode *ProfileData, uint64_t &TotalVal) {
if (!ProfDataName)
return false;
if (ProfDataName->getString() == "branch_weights") {
if (ProfDataName->getString() == MDProfLabels::BranchWeights) {
unsigned Offset = getBranchWeightOffset(ProfileData);
for (unsigned Idx = Offset; Idx < ProfileData->getNumOperands(); ++Idx) {
auto *V = mdconst::extract<ConstantInt>(ProfileData->getOperand(Idx));
@@ -219,7 +227,8 @@ bool extractProfTotalWeight(const MDNode *ProfileData, uint64_t &TotalVal) {
return true;
}
if (ProfDataName->getString() == "VP" && ProfileData->getNumOperands() > 3) {
if (ProfDataName->getString() == MDProfLabels::ValueProfile &&
ProfileData->getNumOperands() > 3) {
TotalVal = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2))
->getValue()
.getZExtValue();
@@ -246,8 +255,9 @@ void scaleProfData(Instruction &I, uint64_t S, uint64_t T) {
return;
auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
if (!ProfDataName || (ProfDataName->getString() != "branch_weights" &&
ProfDataName->getString() != "VP"))
if (!ProfDataName ||
(ProfDataName->getString() != MDProfLabels::BranchWeights &&
ProfDataName->getString() != MDProfLabels::ValueProfile))
return;
if (!hasCountTypeMD(I))
@@ -259,7 +269,7 @@ void scaleProfData(Instruction &I, uint64_t S, uint64_t T) {
SmallVector<Metadata *, 3> Vals;
Vals.push_back(ProfileData->getOperand(0));
APInt APS(128, S), APT(128, T);
if (ProfDataName->getString() == "branch_weights" &&
if (ProfDataName->getString() == MDProfLabels::BranchWeights &&
ProfileData->getNumOperands() > 0) {
// Using APInt::div may be expensive, but most cases should fit 64 bits.
APInt Val(128,
@@ -270,7 +280,7 @@ void scaleProfData(Instruction &I, uint64_t S, uint64_t T) {
Val *= APS;
Vals.push_back(MDB.createConstant(ConstantInt::get(
Type::getInt32Ty(C), Val.udiv(APT).getLimitedValue(UINT32_MAX))));
} else if (ProfDataName->getString() == "VP")
} else if (ProfDataName->getString() == MDProfLabels::ValueProfile)
for (unsigned Idx = 1; Idx < ProfileData->getNumOperands(); Idx += 2) {
// The first value is the key of the value profile, which will not change.
Vals.push_back(ProfileData->getOperand(Idx));

10
llvm/lib/IR/Verifier.cpp
View File

@@ -2536,8 +2536,8 @@ void Verifier::verifyFunctionMetadata(
"expected string with name of the !prof annotation", MD);
MDString *MDS = cast<MDString>(MD->getOperand(0));
StringRef ProfName = MDS->getString();
Check(ProfName == "function_entry_count" ||
ProfName == "synthetic_function_entry_count",
Check(ProfName == MDProfLabels::FunctionEntryCount ||
ProfName == MDProfLabels::SyntheticFunctionEntryCount,
"first operand should be 'function_entry_count'"
" or 'synthetic_function_entry_count'",
MD);
@@ -4993,7 +4993,7 @@ void Verifier::visitProfMetadata(Instruction &I, MDNode *MD) {
StringRef ProfName = MDS->getString();
// Check consistency of !prof branch_weights metadata.
if (ProfName == "branch_weights") {
if (ProfName == MDProfLabels::BranchWeights) {
unsigned NumBranchWeights = getNumBranchWeights(*MD);
if (isa<InvokeInst>(&I)) {
Check(NumBranchWeights == 1 || NumBranchWeights == 2,
@@ -5027,8 +5027,8 @@ void Verifier::visitProfMetadata(Instruction &I, MDNode *MD) {
"!prof brunch_weights operand is not a const int");
}
} else {
Check(ProfName == "VP", "expected either branch_weights or VP profile name",
MD);
Check(ProfName == MDProfLabels::ValueProfile,
"expected either branch_weights or VP profile name", MD);
}
}

5
llvm/lib/ProfileData/InstrProf.cpp
View File

@@ -27,6 +27,7 @@
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ProfDataUtils.h"
#include "llvm/IR/Type.h"
#include "llvm/ProfileData/InstrProfReader.h"
#include "llvm/Support/Casting.h"
@@ -1358,7 +1359,7 @@ void annotateValueSite(Module &M, Instruction &Inst,
MDBuilder MDHelper(Ctx);
SmallVector<Metadata *, 3> Vals;
// Tag
Vals.push_back(MDHelper.createString("VP"));
Vals.push_back(MDHelper.createString(MDProfLabels::ValueProfile));
// Value Kind
Vals.push_back(MDHelper.createConstant(
ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
@@ -1389,7 +1390,7 @@ MDNode *mayHaveValueProfileOfKind(const Instruction &Inst,
return nullptr;
MDString *Tag = cast<MDString>(MD->getOperand(0));
if (!Tag || Tag->getString() != "VP")
if (!Tag || Tag->getString() != MDProfLabels::ValueProfile)
return nullptr;
// Now check kind: