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[FMV][AArch64] Allow user to override version priority. #150267

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@labrinea labrinea commented Jul 23, 2025

Implements ARM-software/acle#404

This allows the user to specify "priority=[1-32];featA+featB" where priority=31 means highest priority. If the explicit priority string is omitted then the priority of "featA+featB" is implied, which is lower than priority=1.

Internally this gets expanded using special FMV features P0 ... P4 which can encode up to 31 priority levels (excluding all zeros). Those do not have corresponding detection bit at pos FEAT_#enum so I made this field optional in FMVInfo. Also they don't affect the codegen or name mangling of versioned functions.

Implements ARM-software/acle#404

This allows the user to specify "priority=[1-32];featA+featB"
where priority=31 means highest priority. If the explicit
priority string is omitted then the priority of "featA+featB"
is implied, which is lower than priority=1.

Internally this gets expanded using special FMV features P0 ... P5
which can encode up to 31 priority levels (excluding all zeros).
Those do not have corresponding detection bit at pos FEAT_#enum
so I made this field optional in FMVInfo. Also they don't affect
the codegen or name mangling of versioned functions.
@llvmbot llvmbot added clang Clang issues not falling into any other category backend:ARM backend:AArch64 backend:RISC-V clang:frontend Language frontend issues, e.g. anything involving "Sema" clang:codegen IR generation bugs: mangling, exceptions, etc. tablegen llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms labels Jul 23, 2025
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llvmbot commented Jul 23, 2025

@llvm/pr-subscribers-tablegen
@llvm/pr-subscribers-backend-risc-v
@llvm/pr-subscribers-clang-codegen

@llvm/pr-subscribers-backend-arm

Author: Alexandros Lamprineas (labrinea)

Changes

Implements ARM-software/acle#404

This allows the user to specify "priority=[1-32];featA+featB" where priority=31 means highest priority. If the explicit priority string is omitted then the priority of "featA+featB" is implied, which is lower than priority=1.

Internally this gets expanded using special FMV features P0 ... P5 which can encode up to 31 priority levels (excluding all zeros). Those do not have corresponding detection bit at pos FEAT_#enum so I made this field optional in FMVInfo. Also they don't affect the codegen or name mangling of versioned functions.


Patch is 39.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/150267.diff

23 Files Affected:

  • (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+6)
  • (modified) clang/include/clang/Sema/SemaARM.h (+2-1)
  • (modified) clang/include/clang/Sema/SemaRISCV.h (+2-1)
  • (modified) clang/lib/CodeGen/Targets/AArch64.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaARM.cpp (+54-8)
  • (modified) clang/lib/Sema/SemaDeclAttr.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaRISCV.cpp (+3-1)
  • (modified) clang/test/AST/attr-target-version.c (+20-4)
  • (modified) clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c (+16)
  • (added) clang/test/CodeGen/AArch64/fmv-explicit-priority.c (+193)
  • (modified) clang/test/Sema/attr-target-clones-aarch64.c (+10)
  • (modified) clang/test/Sema/attr-target-version.c (+9)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfo.h (+5-1)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfoImpl.h (+4)
  • (modified) llvm/include/llvm/TargetParser/AArch64FeatPriorities.inc (+7-1)
  • (modified) llvm/include/llvm/TargetParser/AArch64TargetParser.h (+7-4)
  • (modified) llvm/lib/Analysis/TargetTransformInfo.cpp (+4)
  • (modified) llvm/lib/Target/AArch64/AArch64FMV.td (+8)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp (+14-3)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h (+1)
  • (modified) llvm/lib/TargetParser/AArch64TargetParser.cpp (+20-11)
  • (modified) llvm/lib/Transforms/IPO/GlobalOpt.cpp (+15-7)
  • (modified) llvm/utils/TableGen/Basic/ARMTargetDefEmitter.cpp (+6-3)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index b2ea65ae111be..05fecee73270f 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -12747,6 +12747,12 @@ def warn_target_clone_duplicate_options
 def warn_target_clone_no_impact_options
     : Warning<"version list contains entries that don't impact code generation">,
       InGroup<FunctionMultiVersioning>;
+def warn_version_priority_out_of_range
+    : Warning<"version priority '%0' is outside the allowed range [1-31]; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
+def warn_invalid_default_version_priority
+    : Warning<"priority of default version cannot be overridden; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
 
 // three-way comparison operator diagnostics
 def err_implied_comparison_category_type_not_found : Error<
diff --git a/clang/include/clang/Sema/SemaARM.h b/clang/include/clang/Sema/SemaARM.h
index e77d65f9362d8..1a2775d7b050e 100644
--- a/clang/include/clang/Sema/SemaARM.h
+++ b/clang/include/clang/Sema/SemaARM.h
@@ -92,7 +92,8 @@ class SemaARM : public SemaBase {
   /// false otherwise.
   bool areLaxCompatibleSveTypes(QualType FirstType, QualType SecondType);
 
-  bool checkTargetVersionAttr(const StringRef Str, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/include/clang/Sema/SemaRISCV.h b/clang/include/clang/Sema/SemaRISCV.h
index 844cc3ce4a440..863b8a143f48a 100644
--- a/clang/include/clang/Sema/SemaRISCV.h
+++ b/clang/include/clang/Sema/SemaRISCV.h
@@ -56,7 +56,8 @@ class SemaRISCV : public SemaBase {
 
   std::unique_ptr<sema::RISCVIntrinsicManager> IntrinsicManager;
 
-  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp
index b82c46966cf0b..f451562b86ec3 100644
--- a/clang/lib/CodeGen/Targets/AArch64.cpp
+++ b/clang/lib/CodeGen/Targets/AArch64.cpp
@@ -1337,9 +1337,10 @@ void AArch64ABIInfo::appendAttributeMangling(StringRef AttrStr,
 
   llvm::SmallDenseSet<StringRef, 8> UniqueFeats;
   for (auto &Feat : Features)
-    if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
-      if (UniqueFeats.insert(Ext->Name).second)
-        Out << 'M' << Ext->Name;
+    if (getTarget().doesFeatureAffectCodeGen(Feat))
+      if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
+        if (UniqueFeats.insert(Ext->Name).second)
+          Out << 'M' << Ext->Name;
 }
 
 std::unique_ptr<TargetCodeGenInfo>
diff --git a/clang/lib/Sema/SemaARM.cpp b/clang/lib/Sema/SemaARM.cpp
index 8e27fabccd583..d3110dd18e927 100644
--- a/clang/lib/Sema/SemaARM.cpp
+++ b/clang/lib/Sema/SemaARM.cpp
@@ -1535,19 +1535,52 @@ bool SemaARM::areLaxCompatibleSveTypes(QualType FirstType,
          IsLaxCompatible(SecondType, FirstType);
 }
 
+static void appendFeature(StringRef Feat, SmallString<64> &Buffer) {
+  if (!Buffer.empty())
+    Buffer.append("+");
+  Buffer.append(Feat);
+}
+
+static void convertPriorityString(unsigned Priority,
+                                  SmallString<64> &NewParam) {
+  StringRef PriorityString[5] = {"P0", "P1", "P2", "P3", "P4"};
+
+  assert(Priority > 0 && Priority < 32 && "priority out of range");
+  // Convert priority=[1-31] -> P0 + ... + P4
+  for (unsigned BitPos = 0; BitPos < 5; ++BitPos)
+    if (Priority & (1U << BitPos))
+      appendFeature(PriorityString[BitPos], NewParam);
+}
+
 bool SemaARM::checkTargetVersionAttr(const StringRef Param,
-                                     const SourceLocation Loc) {
+                                     const SourceLocation Loc,
+                                     SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
+  auto [LHS, RHS] = Param.split(';');
+  bool IsDefault = false;
   llvm::SmallVector<StringRef, 8> Features;
-  Param.split(Features, '+');
+  LHS.split(Features, '+');
   for (StringRef Feat : Features) {
     Feat = Feat.trim();
     if (Feat == "default")
-      continue;
-    if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
+      IsDefault = true;
+    else if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << Feat << TargetVersion;
+    appendFeature(Feat, NewParam);
+  }
+
+  if (!RHS.empty() && RHS.consume_front("priority=")) {
+    if (IsDefault)
+      Diag(Loc, diag::warn_invalid_default_version_priority);
+    else {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
   }
   return false;
 }
@@ -1569,15 +1602,20 @@ bool SemaARM::checkTargetClonesAttr(
     const StringRef Param = Params[I].trim();
     const SourceLocation &Loc = Locs[I];
 
-    if (Param.empty())
+    auto [LHS, RHS] = Param.split(';');
+    bool HasPriority = !RHS.empty() && RHS.consume_front("priority=");
+
+    if (LHS.empty())
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << "" << TargetClones;
 
-    if (Param == "default") {
+    if (LHS == "default") {
       if (HasDefault)
         Diag(Loc, diag::warn_target_clone_duplicate_options);
       else {
-        NewParams.push_back(Param);
+        if (HasPriority)
+          Diag(Loc, diag::warn_invalid_default_version_priority);
+        NewParams.push_back(LHS);
         HasDefault = true;
       }
       continue;
@@ -1586,7 +1624,7 @@ bool SemaARM::checkTargetClonesAttr(
     bool HasCodeGenImpact = false;
     llvm::SmallVector<StringRef, 8> Features;
     llvm::SmallVector<StringRef, 8> ValidFeatures;
-    Param.split(Features, '+');
+    LHS.split(Features, '+');
     for (StringRef Feat : Features) {
       Feat = Feat.trim();
       if (!getASTContext().getTargetInfo().validateCpuSupports(Feat)) {
@@ -1616,6 +1654,14 @@ bool SemaARM::checkTargetClonesAttr(
       continue;
     }
 
+    if (HasPriority) {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
+
     // Valid non-default argument.
     NewParams.push_back(NewParam);
     HasNonDefault = true;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 9a2950cf1648e..46f4bab9edc71 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3333,19 +3333,20 @@ bool Sema::checkTargetAttr(SourceLocation LiteralLoc, StringRef AttrStr) {
 static void handleTargetVersionAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   StringRef Param;
   SourceLocation Loc;
+  SmallString<64> NewParam;
   if (!S.checkStringLiteralArgumentAttr(AL, 0, Param, &Loc))
     return;
 
   if (S.Context.getTargetInfo().getTriple().isAArch64()) {
-    if (S.ARM().checkTargetVersionAttr(Param, Loc))
+    if (S.ARM().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   } else if (S.Context.getTargetInfo().getTriple().isRISCV()) {
-    if (S.RISCV().checkTargetVersionAttr(Param, Loc))
+    if (S.RISCV().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   }
 
   TargetVersionAttr *NewAttr =
-      ::new (S.Context) TargetVersionAttr(S.Context, AL, Param);
+      ::new (S.Context) TargetVersionAttr(S.Context, AL, NewParam);
   D->addAttr(NewAttr);
 }
 
diff --git a/clang/lib/Sema/SemaRISCV.cpp b/clang/lib/Sema/SemaRISCV.cpp
index 994cd07c1e263..bb91bd7aefbb4 100644
--- a/clang/lib/Sema/SemaRISCV.cpp
+++ b/clang/lib/Sema/SemaRISCV.cpp
@@ -1636,7 +1636,8 @@ bool SemaRISCV::isValidFMVExtension(StringRef Ext) {
 }
 
 bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
-                                       const SourceLocation Loc) {
+                                       const SourceLocation Loc,
+                                       SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
   llvm::SmallVector<StringRef, 8> AttrStrs;
@@ -1682,6 +1683,7 @@ bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
     return Diag(Loc, diag::warn_unsupported_target_attribute)
            << Unsupported << None << Param << TargetVersion;
 
+  NewParam = Param;
   return false;
 }
 
diff --git a/clang/test/AST/attr-target-version.c b/clang/test/AST/attr-target-version.c
index b537f5e685a31..c7b83bef1b91b 100644
--- a/clang/test/AST/attr-target-version.c
+++ b/clang/test/AST/attr-target-version.c
@@ -2,7 +2,23 @@
 
 int __attribute__((target_version("sve2-bitperm + sha2"))) foov(void) { return 1; }
 int __attribute__((target_clones(" lse + fp + sha3 ", "default"))) fooc(void) { return 2; }
-// CHECK: TargetVersionAttr
-// CHECK: sve2-bitperm + sha2
-// CHECK: TargetClonesAttr
-// CHECK: fp+lse+sha3 default
+
+int __attribute__((target_version("aes;priority=1"))) explicit_priority(void) { return 1; }
+int __attribute__((target_version("bf16;priority=2"))) explicit_priority(void) { return 2; }
+int __attribute__((target_version("crc;priority=4"))) explicit_priority(void) { return 4; }
+int __attribute__((target_version("dpb2;priority=8"))) explicit_priority(void) { return 8; }
+int __attribute__((target_version("fp16fml;priority=16"))) explicit_priority(void) { return 16; }
+
+int __attribute__((target_clones("simd;priority=31", "default"))) explicit_priority(void) {
+  return 0;
+}
+
+// CHECK: TargetVersionAttr {{.*}} "sve2-bitperm+sha2"
+// CHECK: TargetClonesAttr {{.*}} fp+lse+sha3 default
+
+// CHECK: TargetVersionAttr {{.*}} "aes+P0"
+// CHECK: TargetVersionAttr {{.*}} "bf16+P1"
+// CHECK: TargetVersionAttr {{.*}} "crc+P2"
+// CHECK: TargetVersionAttr {{.*}} "dpb2+P3"
+// CHECK: TargetVersionAttr {{.*}} "fp16fml+P4"
+// CHECK: TargetClonesAttr {{.*}} simd+P0+P1+P2+P3+P4 default
diff --git a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
index e7e611e09542e..ebe5b75cf7946 100644
--- a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
+++ b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_IMPLICIT_DEFAULT
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_DEFAULT
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_VERSION_PRIORITY
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_CLONES_PRIORITY
 
 #if defined(CHECK_IMPLICIT_DEFAULT)
 
@@ -21,4 +23,18 @@ __attribute__((target_version("default"))) int explicit_default_bad(void) { retu
 // expected-note@-2 {{previous definition is here}}
 __attribute__((target_clones("aes", "lse", "default"))) int explicit_default_bad(void) { return 1; }
 
+#elif defined(CHECK_EXPLICIT_VERSION_PRIORITY)
+
+__attribute__((target_version("aes"))) int explicit_version_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_version_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_version("aes;priority=10"))) int explicit_version_priority(void) { return 1; }
+
+#elif defined(CHECK_EXPLICIT_CLONES_PRIORITY)
+
+__attribute__((target_version("aes;priority=20"))) int explicit_clones_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_clones_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_clones("aes;priority=5", "lse"))) int explicit_clones_priority(void) { return 1; }
+
 #endif
diff --git a/clang/test/CodeGen/AArch64/fmv-explicit-priority.c b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
new file mode 100644
index 0000000000000..437221c95542b
--- /dev/null
+++ b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
@@ -0,0 +1,193 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature --check-attributes --check-globals --include-generated-funcs
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -O3 -fno-inline -emit-llvm -o - %s | FileCheck %s
+
+__attribute__((target_version("lse;priority=30"))) int foo(void) { return 1; }
+__attribute__((target_version("sve2;priority=20"))) int foo(void) { return 2; }
+__attribute__((target_version("sve;priority=10"))) int foo(void) { return 3; }
+__attribute__((target_version( "default"))) int foo(void) { return 0; }
+
+__attribute__((target_clones("lse+sve2;priority=3", "lse;priority=2", "sve;priority=1", "default")))
+int fmv_caller(void) { return foo(); }
+
+
+__attribute__((target_version("aes"))) int bar(void) { return 1; }
+__attribute__((target_version("sm4;priority=5"))) int bar(void) { return 2; }
+__attribute__((target_version("default"))) int bar(void) { return 0; }
+
+__attribute__((target("aes"))) int regular_caller_aes() { return bar(); }
+__attribute__((target("sm4"))) int regular_caller_sm4() { return bar(); }
+//.
+// CHECK: @__aarch64_cpu_features = external dso_local local_unnamed_addr global { i64 }
+// CHECK: @foo = weak_odr ifunc i32 (), ptr @foo.resolver
+// CHECK: @fmv_caller = weak_odr ifunc i32 (), ptr @fmv_caller.resolver
+// CHECK: @bar = weak_odr ifunc i32 (), ptr @bar.resolver
+//.
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo._Mlse
+// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve2
+// CHECK-SAME: () #[[ATTR1:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve
+// CHECK-SAME: () #[[ATTR2:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 3
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo.default
+// CHECK-SAME: () #[[ATTR3:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._MlseMsve2
+// CHECK-SAME: () #[[ATTR4:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Mlse
+// CHECK-SAME: () #[[ATTR5:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: noinline nounwind vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Msve
+// CHECK-SAME: () #[[ATTR6:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo() #[[ATTR12:[0-9]+]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.default
+// CHECK-SAME: () #[[ATTR7:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo.default()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Maes
+// CHECK-SAME: () #[[ATTR8:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Msm4
+// CHECK-SAME: () #[[ATTR9:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar.default
+// CHECK-SAME: () #[[ATTR3]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: noinline nounwind
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_aes
+// CHECK-SAME: () local_unnamed_addr #[[ATTR10:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar() #[[ATTR12]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_sm4
+// CHECK-SAME: () local_unnamed_addr #[[ATTR11:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar._Msm4()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@foo.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP1]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE:%.*]], label [[COMMON_RET:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @foo._Mlse, [[RESOLVER_ENTRY:%.*]] ], [ @foo._Msve2, [[RESOLVER_ELSE]] ], [ [[FOO__MSVE_FOO_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP0]], 69793284352
+// CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 69793284352
+// CHECK-NEXT:    br i1 [[TMP3]], label [[COMMON_RET]], label [[RESOLVER_ELSE2]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FOO__MSVE_FOO_DEFAULT]] = select i1 [[TMP5]], ptr @foo._Msve, ptr @foo.default
+// CHECK-NEXT:    br label [[COMMON_RET]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 69793284480
+// CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 69793284480
+// CHECK-NEXT:    br i1 [[TMP2]], label [[COMMON_RET:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @fmv_caller._MlseMsve2, [[RESOLVER_ENTRY:%.*]] ], [ @fmv_caller._Mlse, [[RESOLVER_ELSE]] ], [ [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP3]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE2]], label [[COMMON_RET]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT]] = select i1 [[TMP5]], ptr @fmv_call...
[truncated]

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llvmbot commented Jul 23, 2025

@llvm/pr-subscribers-llvm-transforms

Author: Alexandros Lamprineas (labrinea)

Changes

Implements ARM-software/acle#404

This allows the user to specify "priority=[1-32];featA+featB" where priority=31 means highest priority. If the explicit priority string is omitted then the priority of "featA+featB" is implied, which is lower than priority=1.

Internally this gets expanded using special FMV features P0 ... P5 which can encode up to 31 priority levels (excluding all zeros). Those do not have corresponding detection bit at pos FEAT_#enum so I made this field optional in FMVInfo. Also they don't affect the codegen or name mangling of versioned functions.


Patch is 39.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/150267.diff

23 Files Affected:

  • (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+6)
  • (modified) clang/include/clang/Sema/SemaARM.h (+2-1)
  • (modified) clang/include/clang/Sema/SemaRISCV.h (+2-1)
  • (modified) clang/lib/CodeGen/Targets/AArch64.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaARM.cpp (+54-8)
  • (modified) clang/lib/Sema/SemaDeclAttr.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaRISCV.cpp (+3-1)
  • (modified) clang/test/AST/attr-target-version.c (+20-4)
  • (modified) clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c (+16)
  • (added) clang/test/CodeGen/AArch64/fmv-explicit-priority.c (+193)
  • (modified) clang/test/Sema/attr-target-clones-aarch64.c (+10)
  • (modified) clang/test/Sema/attr-target-version.c (+9)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfo.h (+5-1)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfoImpl.h (+4)
  • (modified) llvm/include/llvm/TargetParser/AArch64FeatPriorities.inc (+7-1)
  • (modified) llvm/include/llvm/TargetParser/AArch64TargetParser.h (+7-4)
  • (modified) llvm/lib/Analysis/TargetTransformInfo.cpp (+4)
  • (modified) llvm/lib/Target/AArch64/AArch64FMV.td (+8)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp (+14-3)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h (+1)
  • (modified) llvm/lib/TargetParser/AArch64TargetParser.cpp (+20-11)
  • (modified) llvm/lib/Transforms/IPO/GlobalOpt.cpp (+15-7)
  • (modified) llvm/utils/TableGen/Basic/ARMTargetDefEmitter.cpp (+6-3)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index b2ea65ae111be..05fecee73270f 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -12747,6 +12747,12 @@ def warn_target_clone_duplicate_options
 def warn_target_clone_no_impact_options
     : Warning<"version list contains entries that don't impact code generation">,
       InGroup<FunctionMultiVersioning>;
+def warn_version_priority_out_of_range
+    : Warning<"version priority '%0' is outside the allowed range [1-31]; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
+def warn_invalid_default_version_priority
+    : Warning<"priority of default version cannot be overridden; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
 
 // three-way comparison operator diagnostics
 def err_implied_comparison_category_type_not_found : Error<
diff --git a/clang/include/clang/Sema/SemaARM.h b/clang/include/clang/Sema/SemaARM.h
index e77d65f9362d8..1a2775d7b050e 100644
--- a/clang/include/clang/Sema/SemaARM.h
+++ b/clang/include/clang/Sema/SemaARM.h
@@ -92,7 +92,8 @@ class SemaARM : public SemaBase {
   /// false otherwise.
   bool areLaxCompatibleSveTypes(QualType FirstType, QualType SecondType);
 
-  bool checkTargetVersionAttr(const StringRef Str, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/include/clang/Sema/SemaRISCV.h b/clang/include/clang/Sema/SemaRISCV.h
index 844cc3ce4a440..863b8a143f48a 100644
--- a/clang/include/clang/Sema/SemaRISCV.h
+++ b/clang/include/clang/Sema/SemaRISCV.h
@@ -56,7 +56,8 @@ class SemaRISCV : public SemaBase {
 
   std::unique_ptr<sema::RISCVIntrinsicManager> IntrinsicManager;
 
-  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp
index b82c46966cf0b..f451562b86ec3 100644
--- a/clang/lib/CodeGen/Targets/AArch64.cpp
+++ b/clang/lib/CodeGen/Targets/AArch64.cpp
@@ -1337,9 +1337,10 @@ void AArch64ABIInfo::appendAttributeMangling(StringRef AttrStr,
 
   llvm::SmallDenseSet<StringRef, 8> UniqueFeats;
   for (auto &Feat : Features)
-    if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
-      if (UniqueFeats.insert(Ext->Name).second)
-        Out << 'M' << Ext->Name;
+    if (getTarget().doesFeatureAffectCodeGen(Feat))
+      if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
+        if (UniqueFeats.insert(Ext->Name).second)
+          Out << 'M' << Ext->Name;
 }
 
 std::unique_ptr<TargetCodeGenInfo>
diff --git a/clang/lib/Sema/SemaARM.cpp b/clang/lib/Sema/SemaARM.cpp
index 8e27fabccd583..d3110dd18e927 100644
--- a/clang/lib/Sema/SemaARM.cpp
+++ b/clang/lib/Sema/SemaARM.cpp
@@ -1535,19 +1535,52 @@ bool SemaARM::areLaxCompatibleSveTypes(QualType FirstType,
          IsLaxCompatible(SecondType, FirstType);
 }
 
+static void appendFeature(StringRef Feat, SmallString<64> &Buffer) {
+  if (!Buffer.empty())
+    Buffer.append("+");
+  Buffer.append(Feat);
+}
+
+static void convertPriorityString(unsigned Priority,
+                                  SmallString<64> &NewParam) {
+  StringRef PriorityString[5] = {"P0", "P1", "P2", "P3", "P4"};
+
+  assert(Priority > 0 && Priority < 32 && "priority out of range");
+  // Convert priority=[1-31] -> P0 + ... + P4
+  for (unsigned BitPos = 0; BitPos < 5; ++BitPos)
+    if (Priority & (1U << BitPos))
+      appendFeature(PriorityString[BitPos], NewParam);
+}
+
 bool SemaARM::checkTargetVersionAttr(const StringRef Param,
-                                     const SourceLocation Loc) {
+                                     const SourceLocation Loc,
+                                     SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
+  auto [LHS, RHS] = Param.split(';');
+  bool IsDefault = false;
   llvm::SmallVector<StringRef, 8> Features;
-  Param.split(Features, '+');
+  LHS.split(Features, '+');
   for (StringRef Feat : Features) {
     Feat = Feat.trim();
     if (Feat == "default")
-      continue;
-    if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
+      IsDefault = true;
+    else if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << Feat << TargetVersion;
+    appendFeature(Feat, NewParam);
+  }
+
+  if (!RHS.empty() && RHS.consume_front("priority=")) {
+    if (IsDefault)
+      Diag(Loc, diag::warn_invalid_default_version_priority);
+    else {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
   }
   return false;
 }
@@ -1569,15 +1602,20 @@ bool SemaARM::checkTargetClonesAttr(
     const StringRef Param = Params[I].trim();
     const SourceLocation &Loc = Locs[I];
 
-    if (Param.empty())
+    auto [LHS, RHS] = Param.split(';');
+    bool HasPriority = !RHS.empty() && RHS.consume_front("priority=");
+
+    if (LHS.empty())
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << "" << TargetClones;
 
-    if (Param == "default") {
+    if (LHS == "default") {
       if (HasDefault)
         Diag(Loc, diag::warn_target_clone_duplicate_options);
       else {
-        NewParams.push_back(Param);
+        if (HasPriority)
+          Diag(Loc, diag::warn_invalid_default_version_priority);
+        NewParams.push_back(LHS);
         HasDefault = true;
       }
       continue;
@@ -1586,7 +1624,7 @@ bool SemaARM::checkTargetClonesAttr(
     bool HasCodeGenImpact = false;
     llvm::SmallVector<StringRef, 8> Features;
     llvm::SmallVector<StringRef, 8> ValidFeatures;
-    Param.split(Features, '+');
+    LHS.split(Features, '+');
     for (StringRef Feat : Features) {
       Feat = Feat.trim();
       if (!getASTContext().getTargetInfo().validateCpuSupports(Feat)) {
@@ -1616,6 +1654,14 @@ bool SemaARM::checkTargetClonesAttr(
       continue;
     }
 
+    if (HasPriority) {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
+
     // Valid non-default argument.
     NewParams.push_back(NewParam);
     HasNonDefault = true;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 9a2950cf1648e..46f4bab9edc71 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3333,19 +3333,20 @@ bool Sema::checkTargetAttr(SourceLocation LiteralLoc, StringRef AttrStr) {
 static void handleTargetVersionAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   StringRef Param;
   SourceLocation Loc;
+  SmallString<64> NewParam;
   if (!S.checkStringLiteralArgumentAttr(AL, 0, Param, &Loc))
     return;
 
   if (S.Context.getTargetInfo().getTriple().isAArch64()) {
-    if (S.ARM().checkTargetVersionAttr(Param, Loc))
+    if (S.ARM().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   } else if (S.Context.getTargetInfo().getTriple().isRISCV()) {
-    if (S.RISCV().checkTargetVersionAttr(Param, Loc))
+    if (S.RISCV().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   }
 
   TargetVersionAttr *NewAttr =
-      ::new (S.Context) TargetVersionAttr(S.Context, AL, Param);
+      ::new (S.Context) TargetVersionAttr(S.Context, AL, NewParam);
   D->addAttr(NewAttr);
 }
 
diff --git a/clang/lib/Sema/SemaRISCV.cpp b/clang/lib/Sema/SemaRISCV.cpp
index 994cd07c1e263..bb91bd7aefbb4 100644
--- a/clang/lib/Sema/SemaRISCV.cpp
+++ b/clang/lib/Sema/SemaRISCV.cpp
@@ -1636,7 +1636,8 @@ bool SemaRISCV::isValidFMVExtension(StringRef Ext) {
 }
 
 bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
-                                       const SourceLocation Loc) {
+                                       const SourceLocation Loc,
+                                       SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
   llvm::SmallVector<StringRef, 8> AttrStrs;
@@ -1682,6 +1683,7 @@ bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
     return Diag(Loc, diag::warn_unsupported_target_attribute)
            << Unsupported << None << Param << TargetVersion;
 
+  NewParam = Param;
   return false;
 }
 
diff --git a/clang/test/AST/attr-target-version.c b/clang/test/AST/attr-target-version.c
index b537f5e685a31..c7b83bef1b91b 100644
--- a/clang/test/AST/attr-target-version.c
+++ b/clang/test/AST/attr-target-version.c
@@ -2,7 +2,23 @@
 
 int __attribute__((target_version("sve2-bitperm + sha2"))) foov(void) { return 1; }
 int __attribute__((target_clones(" lse + fp + sha3 ", "default"))) fooc(void) { return 2; }
-// CHECK: TargetVersionAttr
-// CHECK: sve2-bitperm + sha2
-// CHECK: TargetClonesAttr
-// CHECK: fp+lse+sha3 default
+
+int __attribute__((target_version("aes;priority=1"))) explicit_priority(void) { return 1; }
+int __attribute__((target_version("bf16;priority=2"))) explicit_priority(void) { return 2; }
+int __attribute__((target_version("crc;priority=4"))) explicit_priority(void) { return 4; }
+int __attribute__((target_version("dpb2;priority=8"))) explicit_priority(void) { return 8; }
+int __attribute__((target_version("fp16fml;priority=16"))) explicit_priority(void) { return 16; }
+
+int __attribute__((target_clones("simd;priority=31", "default"))) explicit_priority(void) {
+  return 0;
+}
+
+// CHECK: TargetVersionAttr {{.*}} "sve2-bitperm+sha2"
+// CHECK: TargetClonesAttr {{.*}} fp+lse+sha3 default
+
+// CHECK: TargetVersionAttr {{.*}} "aes+P0"
+// CHECK: TargetVersionAttr {{.*}} "bf16+P1"
+// CHECK: TargetVersionAttr {{.*}} "crc+P2"
+// CHECK: TargetVersionAttr {{.*}} "dpb2+P3"
+// CHECK: TargetVersionAttr {{.*}} "fp16fml+P4"
+// CHECK: TargetClonesAttr {{.*}} simd+P0+P1+P2+P3+P4 default
diff --git a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
index e7e611e09542e..ebe5b75cf7946 100644
--- a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
+++ b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_IMPLICIT_DEFAULT
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_DEFAULT
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_VERSION_PRIORITY
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_CLONES_PRIORITY
 
 #if defined(CHECK_IMPLICIT_DEFAULT)
 
@@ -21,4 +23,18 @@ __attribute__((target_version("default"))) int explicit_default_bad(void) { retu
 // expected-note@-2 {{previous definition is here}}
 __attribute__((target_clones("aes", "lse", "default"))) int explicit_default_bad(void) { return 1; }
 
+#elif defined(CHECK_EXPLICIT_VERSION_PRIORITY)
+
+__attribute__((target_version("aes"))) int explicit_version_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_version_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_version("aes;priority=10"))) int explicit_version_priority(void) { return 1; }
+
+#elif defined(CHECK_EXPLICIT_CLONES_PRIORITY)
+
+__attribute__((target_version("aes;priority=20"))) int explicit_clones_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_clones_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_clones("aes;priority=5", "lse"))) int explicit_clones_priority(void) { return 1; }
+
 #endif
diff --git a/clang/test/CodeGen/AArch64/fmv-explicit-priority.c b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
new file mode 100644
index 0000000000000..437221c95542b
--- /dev/null
+++ b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
@@ -0,0 +1,193 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature --check-attributes --check-globals --include-generated-funcs
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -O3 -fno-inline -emit-llvm -o - %s | FileCheck %s
+
+__attribute__((target_version("lse;priority=30"))) int foo(void) { return 1; }
+__attribute__((target_version("sve2;priority=20"))) int foo(void) { return 2; }
+__attribute__((target_version("sve;priority=10"))) int foo(void) { return 3; }
+__attribute__((target_version( "default"))) int foo(void) { return 0; }
+
+__attribute__((target_clones("lse+sve2;priority=3", "lse;priority=2", "sve;priority=1", "default")))
+int fmv_caller(void) { return foo(); }
+
+
+__attribute__((target_version("aes"))) int bar(void) { return 1; }
+__attribute__((target_version("sm4;priority=5"))) int bar(void) { return 2; }
+__attribute__((target_version("default"))) int bar(void) { return 0; }
+
+__attribute__((target("aes"))) int regular_caller_aes() { return bar(); }
+__attribute__((target("sm4"))) int regular_caller_sm4() { return bar(); }
+//.
+// CHECK: @__aarch64_cpu_features = external dso_local local_unnamed_addr global { i64 }
+// CHECK: @foo = weak_odr ifunc i32 (), ptr @foo.resolver
+// CHECK: @fmv_caller = weak_odr ifunc i32 (), ptr @fmv_caller.resolver
+// CHECK: @bar = weak_odr ifunc i32 (), ptr @bar.resolver
+//.
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo._Mlse
+// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve2
+// CHECK-SAME: () #[[ATTR1:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve
+// CHECK-SAME: () #[[ATTR2:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 3
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo.default
+// CHECK-SAME: () #[[ATTR3:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._MlseMsve2
+// CHECK-SAME: () #[[ATTR4:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Mlse
+// CHECK-SAME: () #[[ATTR5:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: noinline nounwind vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Msve
+// CHECK-SAME: () #[[ATTR6:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo() #[[ATTR12:[0-9]+]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.default
+// CHECK-SAME: () #[[ATTR7:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo.default()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Maes
+// CHECK-SAME: () #[[ATTR8:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Msm4
+// CHECK-SAME: () #[[ATTR9:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar.default
+// CHECK-SAME: () #[[ATTR3]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: noinline nounwind
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_aes
+// CHECK-SAME: () local_unnamed_addr #[[ATTR10:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar() #[[ATTR12]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_sm4
+// CHECK-SAME: () local_unnamed_addr #[[ATTR11:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar._Msm4()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@foo.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP1]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE:%.*]], label [[COMMON_RET:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @foo._Mlse, [[RESOLVER_ENTRY:%.*]] ], [ @foo._Msve2, [[RESOLVER_ELSE]] ], [ [[FOO__MSVE_FOO_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP0]], 69793284352
+// CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 69793284352
+// CHECK-NEXT:    br i1 [[TMP3]], label [[COMMON_RET]], label [[RESOLVER_ELSE2]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FOO__MSVE_FOO_DEFAULT]] = select i1 [[TMP5]], ptr @foo._Msve, ptr @foo.default
+// CHECK-NEXT:    br label [[COMMON_RET]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 69793284480
+// CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 69793284480
+// CHECK-NEXT:    br i1 [[TMP2]], label [[COMMON_RET:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @fmv_caller._MlseMsve2, [[RESOLVER_ENTRY:%.*]] ], [ @fmv_caller._Mlse, [[RESOLVER_ELSE]] ], [ [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP3]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE2]], label [[COMMON_RET]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT]] = select i1 [[TMP5]], ptr @fmv_call...
[truncated]

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llvmbot commented Jul 23, 2025

@llvm/pr-subscribers-llvm-analysis

Author: Alexandros Lamprineas (labrinea)

Changes

Implements ARM-software/acle#404

This allows the user to specify "priority=[1-32];featA+featB" where priority=31 means highest priority. If the explicit priority string is omitted then the priority of "featA+featB" is implied, which is lower than priority=1.

Internally this gets expanded using special FMV features P0 ... P5 which can encode up to 31 priority levels (excluding all zeros). Those do not have corresponding detection bit at pos FEAT_#enum so I made this field optional in FMVInfo. Also they don't affect the codegen or name mangling of versioned functions.


Patch is 39.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/150267.diff

23 Files Affected:

  • (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+6)
  • (modified) clang/include/clang/Sema/SemaARM.h (+2-1)
  • (modified) clang/include/clang/Sema/SemaRISCV.h (+2-1)
  • (modified) clang/lib/CodeGen/Targets/AArch64.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaARM.cpp (+54-8)
  • (modified) clang/lib/Sema/SemaDeclAttr.cpp (+4-3)
  • (modified) clang/lib/Sema/SemaRISCV.cpp (+3-1)
  • (modified) clang/test/AST/attr-target-version.c (+20-4)
  • (modified) clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c (+16)
  • (added) clang/test/CodeGen/AArch64/fmv-explicit-priority.c (+193)
  • (modified) clang/test/Sema/attr-target-clones-aarch64.c (+10)
  • (modified) clang/test/Sema/attr-target-version.c (+9)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfo.h (+5-1)
  • (modified) llvm/include/llvm/Analysis/TargetTransformInfoImpl.h (+4)
  • (modified) llvm/include/llvm/TargetParser/AArch64FeatPriorities.inc (+7-1)
  • (modified) llvm/include/llvm/TargetParser/AArch64TargetParser.h (+7-4)
  • (modified) llvm/lib/Analysis/TargetTransformInfo.cpp (+4)
  • (modified) llvm/lib/Target/AArch64/AArch64FMV.td (+8)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp (+14-3)
  • (modified) llvm/lib/Target/AArch64/AArch64TargetTransformInfo.h (+1)
  • (modified) llvm/lib/TargetParser/AArch64TargetParser.cpp (+20-11)
  • (modified) llvm/lib/Transforms/IPO/GlobalOpt.cpp (+15-7)
  • (modified) llvm/utils/TableGen/Basic/ARMTargetDefEmitter.cpp (+6-3)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index b2ea65ae111be..05fecee73270f 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -12747,6 +12747,12 @@ def warn_target_clone_duplicate_options
 def warn_target_clone_no_impact_options
     : Warning<"version list contains entries that don't impact code generation">,
       InGroup<FunctionMultiVersioning>;
+def warn_version_priority_out_of_range
+    : Warning<"version priority '%0' is outside the allowed range [1-31]; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
+def warn_invalid_default_version_priority
+    : Warning<"priority of default version cannot be overridden; ignoring priority">,
+      InGroup<FunctionMultiVersioning>;
 
 // three-way comparison operator diagnostics
 def err_implied_comparison_category_type_not_found : Error<
diff --git a/clang/include/clang/Sema/SemaARM.h b/clang/include/clang/Sema/SemaARM.h
index e77d65f9362d8..1a2775d7b050e 100644
--- a/clang/include/clang/Sema/SemaARM.h
+++ b/clang/include/clang/Sema/SemaARM.h
@@ -92,7 +92,8 @@ class SemaARM : public SemaBase {
   /// false otherwise.
   bool areLaxCompatibleSveTypes(QualType FirstType, QualType SecondType);
 
-  bool checkTargetVersionAttr(const StringRef Str, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/include/clang/Sema/SemaRISCV.h b/clang/include/clang/Sema/SemaRISCV.h
index 844cc3ce4a440..863b8a143f48a 100644
--- a/clang/include/clang/Sema/SemaRISCV.h
+++ b/clang/include/clang/Sema/SemaRISCV.h
@@ -56,7 +56,8 @@ class SemaRISCV : public SemaBase {
 
   std::unique_ptr<sema::RISCVIntrinsicManager> IntrinsicManager;
 
-  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc);
+  bool checkTargetVersionAttr(const StringRef Param, const SourceLocation Loc,
+                              SmallString<64> &NewParam);
   bool checkTargetClonesAttr(SmallVectorImpl<StringRef> &Params,
                              SmallVectorImpl<SourceLocation> &Locs,
                              SmallVectorImpl<SmallString<64>> &NewParams);
diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp
index b82c46966cf0b..f451562b86ec3 100644
--- a/clang/lib/CodeGen/Targets/AArch64.cpp
+++ b/clang/lib/CodeGen/Targets/AArch64.cpp
@@ -1337,9 +1337,10 @@ void AArch64ABIInfo::appendAttributeMangling(StringRef AttrStr,
 
   llvm::SmallDenseSet<StringRef, 8> UniqueFeats;
   for (auto &Feat : Features)
-    if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
-      if (UniqueFeats.insert(Ext->Name).second)
-        Out << 'M' << Ext->Name;
+    if (getTarget().doesFeatureAffectCodeGen(Feat))
+      if (auto Ext = llvm::AArch64::parseFMVExtension(Feat))
+        if (UniqueFeats.insert(Ext->Name).second)
+          Out << 'M' << Ext->Name;
 }
 
 std::unique_ptr<TargetCodeGenInfo>
diff --git a/clang/lib/Sema/SemaARM.cpp b/clang/lib/Sema/SemaARM.cpp
index 8e27fabccd583..d3110dd18e927 100644
--- a/clang/lib/Sema/SemaARM.cpp
+++ b/clang/lib/Sema/SemaARM.cpp
@@ -1535,19 +1535,52 @@ bool SemaARM::areLaxCompatibleSveTypes(QualType FirstType,
          IsLaxCompatible(SecondType, FirstType);
 }
 
+static void appendFeature(StringRef Feat, SmallString<64> &Buffer) {
+  if (!Buffer.empty())
+    Buffer.append("+");
+  Buffer.append(Feat);
+}
+
+static void convertPriorityString(unsigned Priority,
+                                  SmallString<64> &NewParam) {
+  StringRef PriorityString[5] = {"P0", "P1", "P2", "P3", "P4"};
+
+  assert(Priority > 0 && Priority < 32 && "priority out of range");
+  // Convert priority=[1-31] -> P0 + ... + P4
+  for (unsigned BitPos = 0; BitPos < 5; ++BitPos)
+    if (Priority & (1U << BitPos))
+      appendFeature(PriorityString[BitPos], NewParam);
+}
+
 bool SemaARM::checkTargetVersionAttr(const StringRef Param,
-                                     const SourceLocation Loc) {
+                                     const SourceLocation Loc,
+                                     SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
+  auto [LHS, RHS] = Param.split(';');
+  bool IsDefault = false;
   llvm::SmallVector<StringRef, 8> Features;
-  Param.split(Features, '+');
+  LHS.split(Features, '+');
   for (StringRef Feat : Features) {
     Feat = Feat.trim();
     if (Feat == "default")
-      continue;
-    if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
+      IsDefault = true;
+    else if (!getASTContext().getTargetInfo().validateCpuSupports(Feat))
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << Feat << TargetVersion;
+    appendFeature(Feat, NewParam);
+  }
+
+  if (!RHS.empty() && RHS.consume_front("priority=")) {
+    if (IsDefault)
+      Diag(Loc, diag::warn_invalid_default_version_priority);
+    else {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
   }
   return false;
 }
@@ -1569,15 +1602,20 @@ bool SemaARM::checkTargetClonesAttr(
     const StringRef Param = Params[I].trim();
     const SourceLocation &Loc = Locs[I];
 
-    if (Param.empty())
+    auto [LHS, RHS] = Param.split(';');
+    bool HasPriority = !RHS.empty() && RHS.consume_front("priority=");
+
+    if (LHS.empty())
       return Diag(Loc, diag::warn_unsupported_target_attribute)
              << Unsupported << None << "" << TargetClones;
 
-    if (Param == "default") {
+    if (LHS == "default") {
       if (HasDefault)
         Diag(Loc, diag::warn_target_clone_duplicate_options);
       else {
-        NewParams.push_back(Param);
+        if (HasPriority)
+          Diag(Loc, diag::warn_invalid_default_version_priority);
+        NewParams.push_back(LHS);
         HasDefault = true;
       }
       continue;
@@ -1586,7 +1624,7 @@ bool SemaARM::checkTargetClonesAttr(
     bool HasCodeGenImpact = false;
     llvm::SmallVector<StringRef, 8> Features;
     llvm::SmallVector<StringRef, 8> ValidFeatures;
-    Param.split(Features, '+');
+    LHS.split(Features, '+');
     for (StringRef Feat : Features) {
       Feat = Feat.trim();
       if (!getASTContext().getTargetInfo().validateCpuSupports(Feat)) {
@@ -1616,6 +1654,14 @@ bool SemaARM::checkTargetClonesAttr(
       continue;
     }
 
+    if (HasPriority) {
+      unsigned Digit;
+      if (RHS.getAsInteger(0, Digit) || Digit < 1 || Digit > 31)
+        Diag(Loc, diag::warn_version_priority_out_of_range) << RHS;
+      else
+        convertPriorityString(Digit, NewParam);
+    }
+
     // Valid non-default argument.
     NewParams.push_back(NewParam);
     HasNonDefault = true;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 9a2950cf1648e..46f4bab9edc71 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -3333,19 +3333,20 @@ bool Sema::checkTargetAttr(SourceLocation LiteralLoc, StringRef AttrStr) {
 static void handleTargetVersionAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   StringRef Param;
   SourceLocation Loc;
+  SmallString<64> NewParam;
   if (!S.checkStringLiteralArgumentAttr(AL, 0, Param, &Loc))
     return;
 
   if (S.Context.getTargetInfo().getTriple().isAArch64()) {
-    if (S.ARM().checkTargetVersionAttr(Param, Loc))
+    if (S.ARM().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   } else if (S.Context.getTargetInfo().getTriple().isRISCV()) {
-    if (S.RISCV().checkTargetVersionAttr(Param, Loc))
+    if (S.RISCV().checkTargetVersionAttr(Param, Loc, NewParam))
       return;
   }
 
   TargetVersionAttr *NewAttr =
-      ::new (S.Context) TargetVersionAttr(S.Context, AL, Param);
+      ::new (S.Context) TargetVersionAttr(S.Context, AL, NewParam);
   D->addAttr(NewAttr);
 }
 
diff --git a/clang/lib/Sema/SemaRISCV.cpp b/clang/lib/Sema/SemaRISCV.cpp
index 994cd07c1e263..bb91bd7aefbb4 100644
--- a/clang/lib/Sema/SemaRISCV.cpp
+++ b/clang/lib/Sema/SemaRISCV.cpp
@@ -1636,7 +1636,8 @@ bool SemaRISCV::isValidFMVExtension(StringRef Ext) {
 }
 
 bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
-                                       const SourceLocation Loc) {
+                                       const SourceLocation Loc,
+                                       SmallString<64> &NewParam) {
   using namespace DiagAttrParams;
 
   llvm::SmallVector<StringRef, 8> AttrStrs;
@@ -1682,6 +1683,7 @@ bool SemaRISCV::checkTargetVersionAttr(const StringRef Param,
     return Diag(Loc, diag::warn_unsupported_target_attribute)
            << Unsupported << None << Param << TargetVersion;
 
+  NewParam = Param;
   return false;
 }
 
diff --git a/clang/test/AST/attr-target-version.c b/clang/test/AST/attr-target-version.c
index b537f5e685a31..c7b83bef1b91b 100644
--- a/clang/test/AST/attr-target-version.c
+++ b/clang/test/AST/attr-target-version.c
@@ -2,7 +2,23 @@
 
 int __attribute__((target_version("sve2-bitperm + sha2"))) foov(void) { return 1; }
 int __attribute__((target_clones(" lse + fp + sha3 ", "default"))) fooc(void) { return 2; }
-// CHECK: TargetVersionAttr
-// CHECK: sve2-bitperm + sha2
-// CHECK: TargetClonesAttr
-// CHECK: fp+lse+sha3 default
+
+int __attribute__((target_version("aes;priority=1"))) explicit_priority(void) { return 1; }
+int __attribute__((target_version("bf16;priority=2"))) explicit_priority(void) { return 2; }
+int __attribute__((target_version("crc;priority=4"))) explicit_priority(void) { return 4; }
+int __attribute__((target_version("dpb2;priority=8"))) explicit_priority(void) { return 8; }
+int __attribute__((target_version("fp16fml;priority=16"))) explicit_priority(void) { return 16; }
+
+int __attribute__((target_clones("simd;priority=31", "default"))) explicit_priority(void) {
+  return 0;
+}
+
+// CHECK: TargetVersionAttr {{.*}} "sve2-bitperm+sha2"
+// CHECK: TargetClonesAttr {{.*}} fp+lse+sha3 default
+
+// CHECK: TargetVersionAttr {{.*}} "aes+P0"
+// CHECK: TargetVersionAttr {{.*}} "bf16+P1"
+// CHECK: TargetVersionAttr {{.*}} "crc+P2"
+// CHECK: TargetVersionAttr {{.*}} "dpb2+P3"
+// CHECK: TargetVersionAttr {{.*}} "fp16fml+P4"
+// CHECK: TargetClonesAttr {{.*}} simd+P0+P1+P2+P3+P4 default
diff --git a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
index e7e611e09542e..ebe5b75cf7946 100644
--- a/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
+++ b/clang/test/CodeGen/AArch64/fmv-duplicate-mangled-name.c
@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_IMPLICIT_DEFAULT
 // RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_DEFAULT
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_VERSION_PRIORITY
+// RUN: %clang_cc1 -triple aarch64-linux-gnu -verify -emit-llvm-only %s -DCHECK_EXPLICIT_CLONES_PRIORITY
 
 #if defined(CHECK_IMPLICIT_DEFAULT)
 
@@ -21,4 +23,18 @@ __attribute__((target_version("default"))) int explicit_default_bad(void) { retu
 // expected-note@-2 {{previous definition is here}}
 __attribute__((target_clones("aes", "lse", "default"))) int explicit_default_bad(void) { return 1; }
 
+#elif defined(CHECK_EXPLICIT_VERSION_PRIORITY)
+
+__attribute__((target_version("aes"))) int explicit_version_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_version_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_version("aes;priority=10"))) int explicit_version_priority(void) { return 1; }
+
+#elif defined(CHECK_EXPLICIT_CLONES_PRIORITY)
+
+__attribute__((target_version("aes;priority=20"))) int explicit_clones_priority(void) { return 0; }
+// expected-error@+2 {{definition with same mangled name 'explicit_clones_priority._Maes' as another definition}}
+// expected-note@-2 {{previous definition is here}}
+__attribute__((target_clones("aes;priority=5", "lse"))) int explicit_clones_priority(void) { return 1; }
+
 #endif
diff --git a/clang/test/CodeGen/AArch64/fmv-explicit-priority.c b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
new file mode 100644
index 0000000000000..437221c95542b
--- /dev/null
+++ b/clang/test/CodeGen/AArch64/fmv-explicit-priority.c
@@ -0,0 +1,193 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --function-signature --check-attributes --check-globals --include-generated-funcs
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -O3 -fno-inline -emit-llvm -o - %s | FileCheck %s
+
+__attribute__((target_version("lse;priority=30"))) int foo(void) { return 1; }
+__attribute__((target_version("sve2;priority=20"))) int foo(void) { return 2; }
+__attribute__((target_version("sve;priority=10"))) int foo(void) { return 3; }
+__attribute__((target_version( "default"))) int foo(void) { return 0; }
+
+__attribute__((target_clones("lse+sve2;priority=3", "lse;priority=2", "sve;priority=1", "default")))
+int fmv_caller(void) { return foo(); }
+
+
+__attribute__((target_version("aes"))) int bar(void) { return 1; }
+__attribute__((target_version("sm4;priority=5"))) int bar(void) { return 2; }
+__attribute__((target_version("default"))) int bar(void) { return 0; }
+
+__attribute__((target("aes"))) int regular_caller_aes() { return bar(); }
+__attribute__((target("sm4"))) int regular_caller_sm4() { return bar(); }
+//.
+// CHECK: @__aarch64_cpu_features = external dso_local local_unnamed_addr global { i64 }
+// CHECK: @foo = weak_odr ifunc i32 (), ptr @foo.resolver
+// CHECK: @fmv_caller = weak_odr ifunc i32 (), ptr @fmv_caller.resolver
+// CHECK: @bar = weak_odr ifunc i32 (), ptr @bar.resolver
+//.
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo._Mlse
+// CHECK-SAME: () #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve2
+// CHECK-SAME: () #[[ATTR1:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@foo._Msve
+// CHECK-SAME: () #[[ATTR2:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 3
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@foo.default
+// CHECK-SAME: () #[[ATTR3:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._MlseMsve2
+// CHECK-SAME: () #[[ATTR4:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Mlse
+// CHECK-SAME: () #[[ATTR5:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo._Mlse()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: noinline nounwind vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller._Msve
+// CHECK-SAME: () #[[ATTR6:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo() #[[ATTR12:[0-9]+]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none) vscale_range(1,16)
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.default
+// CHECK-SAME: () #[[ATTR7:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @foo.default()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Maes
+// CHECK-SAME: () #[[ATTR8:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 1
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar._Msm4
+// CHECK-SAME: () #[[ATTR9:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 2
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@bar.default
+// CHECK-SAME: () #[[ATTR3]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    ret i32 0
+//
+//
+// CHECK: Function Attrs: noinline nounwind
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_aes
+// CHECK-SAME: () local_unnamed_addr #[[ATTR10:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar() #[[ATTR12]]
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK: Function Attrs: mustprogress nofree noinline norecurse nosync nounwind willreturn memory(none)
+// CHECK-LABEL: define {{[^@]+}}@regular_caller_sm4
+// CHECK-SAME: () local_unnamed_addr #[[ATTR11:[0-9]+]] {
+// CHECK-NEXT:  entry:
+// CHECK-NEXT:    [[CALL:%.*]] = tail call i32 @bar._Msm4()
+// CHECK-NEXT:    ret i32 [[CALL]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@foo.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP1]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE:%.*]], label [[COMMON_RET:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @foo._Mlse, [[RESOLVER_ENTRY:%.*]] ], [ @foo._Msve2, [[RESOLVER_ELSE]] ], [ [[FOO__MSVE_FOO_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP2:%.*]] = and i64 [[TMP0]], 69793284352
+// CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[TMP2]], 69793284352
+// CHECK-NEXT:    br i1 [[TMP3]], label [[COMMON_RET]], label [[RESOLVER_ELSE2]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FOO__MSVE_FOO_DEFAULT]] = select i1 [[TMP5]], ptr @foo._Msve, ptr @foo.default
+// CHECK-NEXT:    br label [[COMMON_RET]]
+//
+//
+// CHECK-LABEL: define {{[^@]+}}@fmv_caller.resolver() comdat {
+// CHECK-NEXT:  resolver_entry:
+// CHECK-NEXT:    tail call void @__init_cpu_features_resolver()
+// CHECK-NEXT:    [[TMP0:%.*]] = load i64, ptr @__aarch64_cpu_features, align 8
+// CHECK-NEXT:    [[TMP1:%.*]] = and i64 [[TMP0]], 69793284480
+// CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i64 [[TMP1]], 69793284480
+// CHECK-NEXT:    br i1 [[TMP2]], label [[COMMON_RET:%.*]], label [[RESOLVER_ELSE:%.*]]
+// CHECK:       common.ret:
+// CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi ptr [ @fmv_caller._MlseMsve2, [[RESOLVER_ENTRY:%.*]] ], [ @fmv_caller._Mlse, [[RESOLVER_ELSE]] ], [ [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT:%.*]], [[RESOLVER_ELSE2:%.*]] ]
+// CHECK-NEXT:    ret ptr [[COMMON_RET_OP]]
+// CHECK:       resolver_else:
+// CHECK-NEXT:    [[TMP3:%.*]] = and i64 [[TMP0]], 128
+// CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq i64 [[TMP3]], 0
+// CHECK-NEXT:    br i1 [[DOTNOT]], label [[RESOLVER_ELSE2]], label [[COMMON_RET]]
+// CHECK:       resolver_else2:
+// CHECK-NEXT:    [[TMP4:%.*]] = and i64 [[TMP0]], 1073807616
+// CHECK-NEXT:    [[TMP5:%.*]] = icmp eq i64 [[TMP4]], 1073807616
+// CHECK-NEXT:    [[FMV_CALLER__MSVE_FMV_CALLER_DEFAULT]] = select i1 [[TMP5]], ptr @fmv_call...
[truncated]

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github-actions bot commented Jul 23, 2025

✅ With the latest revision this PR passed the C/C++ code formatter.

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backend:AArch64 backend:ARM backend:RISC-V clang:codegen IR generation bugs: mangling, exceptions, etc. clang:frontend Language frontend issues, e.g. anything involving "Sema" clang Clang issues not falling into any other category llvm:analysis Includes value tracking, cost tables and constant folding llvm:transforms tablegen
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