svn commit: r562765 - /apr/apr/trunk/atomic/unix/ia32.c

[da...@apache.org]

Author: davi
Date: Sat Aug  4 14:00:43 2007
New Revision: 562765

URL: http://svn.apache.org/viewvc?view=rev&rev=562765
Log:
Cleanup asm constraints (+ operand is both read and written by the instruction)
and clobbers. The xchg instruction always asserts the lock signal.

Modified:
    apr/apr/trunk/atomic/unix/ia32.c

Modified: apr/apr/trunk/atomic/unix/ia32.c
URL: http://svn.apache.org/viewvc/apr/apr/trunk/atomic/unix/ia32.c?view=diff&rev=562765&r1=562764&r2=562765
==============================================================================
--- apr/apr/trunk/atomic/unix/ia32.c (original)
+++ apr/apr/trunk/atomic/unix/ia32.c Sat Aug  4 14:00:43 2007
@@ -83,10 +83,9 @@
 {
     apr_uint32_t prev = val;
 
-    asm volatile ("lock; xchgl %0, %1"
-                  : "=r" (prev)
-                  : "m" (*(mem)), "0"(prev)
-                  : "memory");
+    asm volatile ("xchgl %0, %1"
+                  : "=r" (prev), "+m" (*mem)
+                  : "0" (prev));
     return prev;
 }
 
@@ -112,15 +111,13 @@
 {
     void *prev;
 #if APR_SIZEOF_VOIDP == 4
-    asm volatile ("lock; xchgl %2, %1"
-                  : "=a" (prev), "=m" (*mem)
-                  : "r" (with), "m" (*mem)
-                  : "memory");
+    asm volatile ("xchgl %2, %1"
+                  : "=a" (prev), "+m" (*mem)
+                  : "0" (with));
 #elif APR_SIZEOF_VOIDP == 8
-    asm volatile ("lock; xchgq %q2, %1"
-                  : "=a" (prev), "=m" (*mem)
-                  : "r" ((unsigned long)with), "m" (*mem)
-                  : "memory");
+    asm volatile ("xchgq %q2, %1"
+                  : "=a" (prev), "+m" (*mem)
+                  : "r" ((unsigned long)with));
 #else
 #error APR_SIZEOF_VOIDP value not supported
 #endif