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 bbe611c5008cd76615877657da2ef89b11f44f87..47690c39121d1c24f18eb1ad693387182f2f80d8 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -56,6 +56,7 @@ The following bugs are resolved with this release:
   [29951] time: Set daylight to 1 for matching DST/offset change
   [30053] time: strftime %s returns -1 after 2038 on 32 bits systems
   [30151] gshadow: Matching sgetsgent, sgetsgent_r ERANGE handling
+  [30305] x86_64: Fix asm constraints in feraiseexcept
 \f
 Version 2.36
 

diff --git a/sysdeps/x86_64/fpu/fraiseexcpt.c b/sysdeps/x86_64/fpu/fraiseexcpt.c
index 864f4777a26d740c6a33357c2227fd25c3770f85..23446ff4acd90aae828086688d621afde5aad303 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;
     }