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>
(cherry picked from commit 5d1ccdda7b0c625751661d50977f3dfbc73f8eae)

diff --git a/NEWS b/NEWS
index aaf2cfcfc305994f68b76ed8c45d3c2df3c56fa1..9dd153477074904ceebefaece43423a727540ece 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,7 @@ The following bugs are resolved with this release:
   [30125] dynamic-link: [regression, bisected] glibc-2.37 creates new
     symlink for libraries without soname
   [30151] gshadow: Matching sgetsgent, sgetsgent_r ERANGE handling
+  [30305] x86_64: Fix asm constraints in feraiseexcept
 \f
 Version 2.37
 

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;
     }