x86_64: Fix asm constraints in feraiseexcept (bug 30305)

The divss instruction clobbers its first argument, and the constraints
need to reflect that.  Fortunately, with GCC 12, generated code does
not actually change, so there is no externally visible bug.

Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>

diff --git a/sysdeps/x86_64/fpu/fraiseexcpt.c b/sysdeps/x86_64/fpu/fraiseexcpt.c
index 924eed96a90de26f6cddb415a83c9ce29ffc7dd6..e7430a4158fb1b9302a8fb6cf503017034a61f8c 100644 (file)
--- a/sysdeps/x86_64/fpu/fraiseexcpt.c
+++ b/sysdeps/x86_64/fpu/fraiseexcpt.c
@@ -33,7 +33,7 @@ __feraiseexcept (int excepts)
       /* One example of an invalid operation is 0.0 / 0.0.  */
       float f = 0.0;
 
-      __asm__ __volatile__ ("divss %0, %0 " : : "x" (f));
+      __asm__ __volatile__ ("divss %0, %0 " : "+x" (f));
       (void) &f;
     }
 
@@ -43,7 +43,7 @@ __feraiseexcept (int excepts)
       float f = 1.0;
       float g = 0.0;
 
-      __asm__ __volatile__ ("divss %1, %0" : : "x" (f), "x" (g));
+      __asm__ __volatile__ ("divss %1, %0" : "+x" (f) : "x" (g));
       (void) &f;
     }