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>
This commit is contained in:
Florian Weimer 2023-04-03 17:23:11 +02:00
parent ac2a14343e
commit 5d1ccdda7b

View File

@ -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;
}