[clang] b6db864 - [AArch64][FMV] Prevent target attribute using for multiversioning.

[Pavel Iliin via cfe-commits]

Author: Pavel Iliin
Date: 2023-05-23T17:29:55+01:00
New Revision: b6db864a2fdf2bcfac62b2c0b71b9ed1cc039c27

URL: https://github.com/llvm/llvm-project/commit/b6db864a2fdf2bcfac62b2c0b71b9ed1cc039c27
DIFF: https://github.com/llvm/llvm-project/commit/b6db864a2fdf2bcfac62b2c0b71b9ed1cc039c27.diff

LOG: [AArch64][FMV] Prevent target attribute using for multiversioning.

On AArch64 for function multiversioning target_version/target_clones
attributes should be used. The patch fixes the defect allowing target
attribute to cause multiversioning.

Differential Revision: https://reviews.llvm.org/D150867

Added: 
    

Modified: 
    clang/lib/Sema/SemaDecl.cpp
    clang/test/Sema/attr-target-version.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index adebfe85be45..2f9c8c70e209 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11540,6 +11540,10 @@ static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD,
     return false;
   }
 
+  // Target attribute on AArch64 is not used for multiversioning
+  if (NewTA && S.getASTContext().getTargetInfo().getTriple().isAArch64())
+    return false;
+
   if (!OldDecl || !OldDecl->getAsFunction() ||
       OldDecl->getDeclContext()->getRedeclContext() !=
           NewFD->getDeclContext()->getRedeclContext()) {

diff  --git a/clang/test/Sema/attr-target-version.c b/clang/test/Sema/attr-target-version.c
index c054b037ee84..0cfec5ecb49c 100644
--- a/clang/test/Sema/attr-target-version.c
+++ b/clang/test/Sema/attr-target-version.c
@@ -15,15 +15,22 @@ int __attribute__((target_version("aes"))) foo(void) { return 1; }
 //expected-note at +1 {{previous definition is here}}
 int __attribute__((target_version("default"))) foo(void) { return 2; }
 
-//expected-note at +1 {{previous declaration is here}}
+//expected-note at +1 {{previous definition is here}}
 int __attribute__((target_version("sha3 + pmull "))) foo(void) { return 1; }
+//expected-note at -1 {{previous definition is here}}
 
-//expected-error at +1 {{multiversioning attributes cannot be combined}}
+//expected-error at +1 {{redefinition of 'foo'}}
 int __attribute__((target("dotprod"))) foo(void) { return -1; }
+//expected-warning at -1 {{attribute declaration must precede definition}}
 
 //expected-error at +1 {{redefinition of 'foo'}}
 int foo(void) { return 2; }
 
+//expected-note at +1 {{previous definition is here}}
+__attribute__ ((target("bf16,sve,sve2,dotprod"))) int func(void) { return 1; }
+//expected-error at +1 {{redefinition of 'func'}}
+__attribute__ ((target("default"))) int func(void) { return 0; }
+
 //expected-note at +1 {{previous declaration is here}}
 void __attribute__((target_version("bti+flagm2"))) one(void) {}
 //expected-error at +1 {{multiversioned function redeclarations require identical target attributes}}