https://github.com/labrinea created
https://github.com/llvm/llvm-project/pull/150079
FMV priority is the returned value of a polymorphic function. On RISC-V and X86
targets a 32-bit value is enough. On AArch64 we currently need 64 bits and we
will soon exceed that. APInt seems to be a suitable replacement for uint64_t,
presumably with minimal compile time overhead. It allows bit manipulation,
comparison and variable bit width.
>From b62c8913fc17b7f85f7e81e02e6bb99eee1ec2a9 Mon Sep 17 00:00:00 2001
From: Alexandros Lamprineas <alexandros.lamprin...@arm.com>
Date: Tue, 22 Jul 2025 17:49:46 +0100
Subject: [PATCH] [NFC][Clang][FMV] Make FMV priority data type future proof.
FMV priority is the returned value of a polymorphic function.
On RISC-V and X86 targets a 32-bit value is enough. On AArch64
we currently need 64 bits and we will soon exceed that. APInt
seems to be a suitable replacement for uint64_t, presumably
with minimal compile time overhead. It allows bit manipulation,
comparison and variable bit width.
---
clang/include/clang/Basic/TargetInfo.h | 4 ++--
clang/lib/Basic/Targets/AArch64.cpp | 3 ++-
clang/lib/Basic/Targets/AArch64.h | 2 +-
clang/lib/Basic/Targets/RISCV.cpp | 9 +++++----
clang/lib/Basic/Targets/RISCV.h | 2 +-
clang/lib/Basic/Targets/X86.cpp | 8 ++++----
clang/lib/Basic/Targets/X86.h | 2 +-
clang/lib/CodeGen/ABIInfo.cpp | 4 ++--
clang/lib/CodeGen/CodeGenModule.cpp | 7 ++++---
clang/lib/CodeGen/TargetBuiltins/ARM.cpp | 4 ++--
llvm/include/llvm/Analysis/TargetTransformInfo.h | 2 +-
llvm/include/llvm/Analysis/TargetTransformInfoImpl.h | 4 +++-
llvm/include/llvm/TargetParser/AArch64TargetParser.h | 4 ++--
llvm/lib/Analysis/TargetTransformInfo.cpp | 2 +-
.../Target/AArch64/AArch64TargetTransformInfo.cpp | 2 +-
llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h | 2 +-
llvm/lib/TargetParser/AArch64TargetParser.cpp | 12 ++++++------
llvm/lib/Transforms/IPO/GlobalOpt.cpp | 12 ++++++------
18 files changed, 45 insertions(+), 40 deletions(-)
diff --git a/clang/include/clang/Basic/TargetInfo.h
b/clang/include/clang/Basic/TargetInfo.h
index 8b66c73474704..abfbdfaa9c0d5 100644
--- a/clang/include/clang/Basic/TargetInfo.h
+++ b/clang/include/clang/Basic/TargetInfo.h
@@ -1551,8 +1551,8 @@ class TargetInfo : public TransferrableTargetInfo,
// Return the target-specific priority for features/cpus/vendors so
// that they can be properly sorted for checking.
- virtual uint64_t getFMVPriority(ArrayRef<StringRef> Features) const {
- return 0;
+ virtual llvm::APInt getFMVPriority(ArrayRef<StringRef> Features) const {
+ return llvm::APInt::getZero(32);
}
// Validate the contents of the __builtin_cpu_is(const char*)
diff --git a/clang/lib/Basic/Targets/AArch64.cpp
b/clang/lib/Basic/Targets/AArch64.cpp
index 72d2e5fcf4619..2b023e5fdb7d8 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -786,7 +786,8 @@ AArch64TargetInfo::getVScaleRange(const LangOptions
&LangOpts,
return std::nullopt;
}
-uint64_t AArch64TargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const
{
+llvm::APInt
+AArch64TargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
return llvm::AArch64::getFMVPriority(Features);
}
diff --git a/clang/lib/Basic/Targets/AArch64.h
b/clang/lib/Basic/Targets/AArch64.h
index f4277e95b19be..dfd89beeee2f3 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -152,7 +152,7 @@ class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public
TargetInfo {
void fillValidCPUList(SmallVectorImpl<StringRef> &Values) const override;
bool setCPU(const std::string &Name) override;
- uint64_t getFMVPriority(ArrayRef<StringRef> Features) const override;
+ llvm::APInt getFMVPriority(ArrayRef<StringRef> Features) const override;
bool useFP16ConversionIntrinsics() const override {
return false;
diff --git a/clang/lib/Basic/Targets/RISCV.cpp
b/clang/lib/Basic/Targets/RISCV.cpp
index 8a28c0788aad7..a6a5ec4b325bc 100644
--- a/clang/lib/Basic/Targets/RISCV.cpp
+++ b/clang/lib/Basic/Targets/RISCV.cpp
@@ -568,7 +568,8 @@ ParsedTargetAttr RISCVTargetInfo::parseTargetAttr(StringRef
Features) const {
return Ret;
}
-uint64_t RISCVTargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
+llvm::APInt
+RISCVTargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
// Priority is explicitly specified on RISC-V unlike on other targets, where
// it is derived by all the features of a specific version. Therefore if a
// feature contains the priority string, then return it immediately.
@@ -580,12 +581,12 @@ uint64_t
RISCVTargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
Feature = RHS;
else
continue;
- uint64_t Priority;
+ unsigned Priority;
if (!Feature.getAsInteger(0, Priority))
- return Priority;
+ return llvm::APInt(32, Priority);
}
// Default Priority is zero.
- return 0;
+ return llvm::APInt::getZero(32);
}
TargetInfo::CallingConvCheckResult
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 8d629abab7bec..58bfad128ce2c 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -123,7 +123,7 @@ class RISCVTargetInfo : public TargetInfo {
void fillValidTuneCPUList(SmallVectorImpl<StringRef> &Values) const override;
bool supportsTargetAttributeTune() const override { return true; }
ParsedTargetAttr parseTargetAttr(StringRef Str) const override;
- uint64_t getFMVPriority(ArrayRef<StringRef> Features) const override;
+ llvm::APInt getFMVPriority(ArrayRef<StringRef> Features) const override;
std::pair<unsigned, unsigned> hardwareInterferenceSizes() const override {
return std::make_pair(32, 32);
diff --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
index a1f5aa26ab2ec..24ecec24d2a4a 100644
--- a/clang/lib/Basic/Targets/X86.cpp
+++ b/clang/lib/Basic/Targets/X86.cpp
@@ -1390,8 +1390,8 @@ static llvm::X86::ProcessorFeatures getFeature(StringRef
Name) {
// correct, so it asserts if the value is out of range.
}
-uint64_t X86TargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
- auto getPriority = [](StringRef Feature) -> uint64_t {
+llvm::APInt X86TargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
+ auto getPriority = [](StringRef Feature) -> unsigned {
// Valid CPUs have a 'key feature' that compares just better than its key
// feature.
using namespace llvm::X86;
@@ -1405,11 +1405,11 @@ uint64_t
X86TargetInfo::getFMVPriority(ArrayRef<StringRef> Features) const {
return getFeaturePriority(getFeature(Feature)) << 1;
};
- uint64_t Priority = 0;
+ unsigned Priority = 0;
for (StringRef Feature : Features)
if (!Feature.empty())
Priority = std::max(Priority, getPriority(Feature));
- return Priority;
+ return llvm::APInt(32, Priority);
}
bool X86TargetInfo::validateCPUSpecificCPUDispatch(StringRef Name) const {
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
index ebc59c92f4c24..eb151034dec85 100644
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -388,7 +388,7 @@ class LLVM_LIBRARY_VISIBILITY X86TargetInfo : public
TargetInfo {
return CPU != llvm::X86::CK_None;
}
- uint64_t getFMVPriority(ArrayRef<StringRef> Features) const override;
+ llvm::APInt getFMVPriority(ArrayRef<StringRef> Features) const override;
bool setFPMath(StringRef Name) override;
diff --git a/clang/lib/CodeGen/ABIInfo.cpp b/clang/lib/CodeGen/ABIInfo.cpp
index d981d69913632..3ef430e19ebd3 100644
--- a/clang/lib/CodeGen/ABIInfo.cpp
+++ b/clang/lib/CodeGen/ABIInfo.cpp
@@ -218,8 +218,8 @@ void ABIInfo::appendAttributeMangling(StringRef AttrStr,
// only have "+" prefixes here.
assert(LHS.starts_with("+") && RHS.starts_with("+") &&
"Features should always have a prefix.");
- return TI.getFMVPriority({LHS.substr(1)}) >
- TI.getFMVPriority({RHS.substr(1)});
+ return TI.getFMVPriority({LHS.substr(1)})
+ .ugt(TI.getFMVPriority({RHS.substr(1)}));
});
bool IsFirst = true;
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp
b/clang/lib/CodeGen/CodeGenModule.cpp
index 236cc3d9e8907..834b1c067d84c 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -4418,8 +4418,9 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD,
llvm::GlobalValue *GV) {
static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
llvm::Function *NewFn);
-static uint64_t getFMVPriority(const TargetInfo &TI,
- const CodeGenFunction::FMVResolverOption &RO) {
+static llvm::APInt
+getFMVPriority(const TargetInfo &TI,
+ const CodeGenFunction::FMVResolverOption &RO) {
llvm::SmallVector<StringRef, 8> Features{RO.Features};
if (RO.Architecture)
Features.push_back(*RO.Architecture);
@@ -4544,7 +4545,7 @@ void CodeGenModule::emitMultiVersionFunctions() {
llvm::stable_sort(
Options, [&TI](const CodeGenFunction::FMVResolverOption &LHS,
const CodeGenFunction::FMVResolverOption &RHS) {
- return getFMVPriority(TI, LHS) > getFMVPriority(TI, RHS);
+ return getFMVPriority(TI, LHS).ugt(getFMVPriority(TI, RHS));
});
CodeGenFunction CGF(*this);
CGF.EmitMultiVersionResolver(ResolverFunc, Options);
diff --git a/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
b/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
index 7e6a47fd7c103..2e6b4b3eb10f1 100644
--- a/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
+++ b/clang/lib/CodeGen/TargetBuiltins/ARM.cpp
@@ -8112,7 +8112,7 @@ Value *CodeGenFunction::EmitAArch64CpuSupports(const
CallExpr *E) {
llvm::Value *
CodeGenFunction::EmitAArch64CpuSupports(ArrayRef<StringRef> FeaturesStrs) {
- uint64_t FeaturesMask = llvm::AArch64::getCpuSupportsMask(FeaturesStrs);
+ llvm::APInt FeaturesMask = llvm::AArch64::getCpuSupportsMask(FeaturesStrs);
Value *Result = Builder.getTrue();
if (FeaturesMask != 0) {
// Get features from structure in runtime library
@@ -8128,7 +8128,7 @@
CodeGenFunction::EmitAArch64CpuSupports(ArrayRef<StringRef> FeaturesStrs) {
{ConstantInt::get(Int32Ty, 0), ConstantInt::get(Int32Ty, 0)});
Value *Features = Builder.CreateAlignedLoad(Int64Ty, CpuFeatures,
CharUnits::fromQuantity(8));
- Value *Mask = Builder.getInt64(FeaturesMask);
+ Value *Mask = Builder.getInt(FeaturesMask.trunc(64));
Value *Bitset = Builder.CreateAnd(Features, Mask);
Value *Cmp = Builder.CreateICmpEQ(Bitset, Mask);
Result = Builder.CreateAnd(Result, Cmp);
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfo.h
b/llvm/include/llvm/Analysis/TargetTransformInfo.h
index 98b793aace7a3..7928835f7f84d 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -1930,7 +1930,7 @@ class TargetTransformInfo {
/// Returns a bitmask constructed from the target-features or fmv-features
/// metadata of a function.
- LLVM_ABI uint64_t getFeatureMask(const Function &F) const;
+ LLVM_ABI APInt getFeatureMask(const Function &F) const;
/// Returns true if this is an instance of a function with multiple versions.
LLVM_ABI bool isMultiversionedFunction(const Function &F) const;
diff --git a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
index ddc8a5eaffa94..2ea87b3c62895 100644
--- a/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
+++ b/llvm/include/llvm/Analysis/TargetTransformInfoImpl.h
@@ -1126,7 +1126,9 @@ class TargetTransformInfoImplBase {
virtual bool hasArmWideBranch(bool) const { return false; }
- virtual uint64_t getFeatureMask(const Function &F) const { return 0; }
+ virtual APInt getFeatureMask(const Function &F) const {
+ return APInt::getZero(32);
+ }
virtual bool isMultiversionedFunction(const Function &F) const {
return false;
diff --git a/llvm/include/llvm/TargetParser/AArch64TargetParser.h
b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
index 59e8117ccb730..8e83b04681f58 100644
--- a/llvm/include/llvm/TargetParser/AArch64TargetParser.h
+++ b/llvm/include/llvm/TargetParser/AArch64TargetParser.h
@@ -276,14 +276,14 @@ LLVM_ABI bool isX18ReservedByDefault(const Triple &TT);
// For a given set of feature names, which can be either target-features, or
// fmv-features metadata, expand their dependencies and then return a bitmask
// corresponding to the entries of AArch64::FeatPriorities.
-LLVM_ABI uint64_t getFMVPriority(ArrayRef<StringRef> Features);
+LLVM_ABI APInt getFMVPriority(ArrayRef<StringRef> Features);
// For a given set of FMV feature names, expand their dependencies and then
// return a bitmask corresponding to the entries of AArch64::CPUFeatures.
// The values in CPUFeatures are not bitmasks themselves, they are sequential
// (0, 1, 2, 3, ...). The resulting bitmask is used at runtime to test whether
// a certain FMV feature is available on the host.
-LLVM_ABI uint64_t getCpuSupportsMask(ArrayRef<StringRef> Features);
+LLVM_ABI APInt getCpuSupportsMask(ArrayRef<StringRef> Features);
LLVM_ABI void PrintSupportedExtensions();
diff --git a/llvm/lib/Analysis/TargetTransformInfo.cpp
b/llvm/lib/Analysis/TargetTransformInfo.cpp
index 8a470ebf85a16..55ba52a1079ce 100644
--- a/llvm/lib/Analysis/TargetTransformInfo.cpp
+++ b/llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -1423,7 +1423,7 @@ bool TargetTransformInfo::hasArmWideBranch(bool Thumb)
const {
return TTIImpl->hasArmWideBranch(Thumb);
}
-uint64_t TargetTransformInfo::getFeatureMask(const Function &F) const {
+APInt TargetTransformInfo::getFeatureMask(const Function &F) const {
return TTIImpl->getFeatureMask(F);
}
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 90d3d92d6bbf5..40f49dade6131 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -249,7 +249,7 @@ static bool hasPossibleIncompatibleOps(const Function *F) {
return false;
}
-uint64_t AArch64TTIImpl::getFeatureMask(const Function &F) const {
+APInt AArch64TTIImpl::getFeatureMask(const Function &F) const {
StringRef AttributeStr =
isMultiversionedFunction(F) ? "fmv-features" : "target-features";
StringRef FeatureStr = F.getFnAttribute(AttributeStr).getValueAsString();
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
index b27eb2ef7a39d..7f45177437237 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h
@@ -89,7 +89,7 @@ class AArch64TTIImpl final : public
BasicTTIImplBase<AArch64TTIImpl> {
unsigned getInlineCallPenalty(const Function *F, const CallBase &Call,
unsigned DefaultCallPenalty) const override;
- uint64_t getFeatureMask(const Function &F) const override;
+ APInt getFeatureMask(const Function &F) const override;
bool isMultiversionedFunction(const Function &F) const override;
diff --git a/llvm/lib/TargetParser/AArch64TargetParser.cpp
b/llvm/lib/TargetParser/AArch64TargetParser.cpp
index 9432fc2c4ac8d..7e3583275a734 100644
--- a/llvm/lib/TargetParser/AArch64TargetParser.cpp
+++ b/llvm/lib/TargetParser/AArch64TargetParser.cpp
@@ -55,7 +55,7 @@ std::optional<AArch64::FMVInfo>
lookupFMVByID(AArch64::ArchExtKind ExtID) {
return {};
}
-uint64_t AArch64::getFMVPriority(ArrayRef<StringRef> Features) {
+APInt AArch64::getFMVPriority(ArrayRef<StringRef> Features) {
// Transitively enable the Arch Extensions which correspond to each feature.
ExtensionSet FeatureBits;
for (const StringRef Feature : Features) {
@@ -69,15 +69,15 @@ uint64_t AArch64::getFMVPriority(ArrayRef<StringRef>
Features) {
}
// Construct a bitmask for all the transitively enabled Arch Extensions.
- uint64_t PriorityMask = 0;
+ APInt PriorityMask = APInt::getZero(128);
for (const FMVInfo &Info : getFMVInfo())
if (Info.ID && FeatureBits.Enabled.test(*Info.ID))
- PriorityMask |= (1ULL << Info.PriorityBit);
+ PriorityMask.setBit(Info.PriorityBit);
return PriorityMask;
}
-uint64_t AArch64::getCpuSupportsMask(ArrayRef<StringRef> Features) {
+APInt AArch64::getCpuSupportsMask(ArrayRef<StringRef> Features) {
// Transitively enable the Arch Extensions which correspond to each feature.
ExtensionSet FeatureBits;
for (const StringRef Feature : Features)
@@ -86,10 +86,10 @@ uint64_t AArch64::getCpuSupportsMask(ArrayRef<StringRef>
Features) {
FeatureBits.enable(*Info->ID);
// Construct a bitmask for all the transitively enabled Arch Extensions.
- uint64_t FeaturesMask = 0;
+ APInt FeaturesMask = APInt::getZero(128);
for (const FMVInfo &Info : getFMVInfo())
if (Info.ID && FeatureBits.Enabled.test(*Info.ID))
- FeaturesMask |= (1ULL << Info.FeatureBit);
+ FeaturesMask.setBit(Info.FeatureBit);
return FeaturesMask;
}
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 2623be3e88fc0..bdda4980c1005 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2529,7 +2529,7 @@ static bool OptimizeNonTrivialIFuncs(
bool Changed = false;
// Cache containing the mask constructed from a function's target features.
- DenseMap<Function *, uint64_t> FeatureMask;
+ DenseMap<Function *, APInt> FeatureMask;
for (GlobalIFunc &IF : M.ifuncs()) {
if (IF.isInterposable())
@@ -2568,7 +2568,7 @@ static bool OptimizeNonTrivialIFuncs(
// Sort the callee versions in decreasing priority order.
sort(Callees, [&](auto *LHS, auto *RHS) {
- return FeatureMask[LHS] > FeatureMask[RHS];
+ return FeatureMask[LHS].ugt(FeatureMask[RHS]);
});
// Find the callsites and cache the feature mask for each caller.
@@ -2591,10 +2591,10 @@ static bool OptimizeNonTrivialIFuncs(
// Sort the caller versions in decreasing priority order.
sort(Callers, [&](auto *LHS, auto *RHS) {
- return FeatureMask[LHS] > FeatureMask[RHS];
+ return FeatureMask[LHS].ugt(FeatureMask[RHS]);
});
- auto implies = [](uint64_t A, uint64_t B) { return (A & B) == B; };
+ auto implies = [](APInt A, APInt B) { return B.isSubsetOf(A); };
// Index to the highest priority candidate.
unsigned I = 0;
@@ -2603,8 +2603,8 @@ static bool OptimizeNonTrivialIFuncs(
assert(I < Callees.size() && "Found callers of equal priority");
Function *Callee = Callees[I];
- uint64_t CallerBits = FeatureMask[Caller];
- uint64_t CalleeBits = FeatureMask[Callee];
+ APInt CallerBits = FeatureMask[Caller];
+ APInt CalleeBits = FeatureMask[Callee];
// In the case of FMV callers, we know that all higher priority callers
// than the current one did not get selected at runtime, which helps
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