Fix asm constraint of CAS memory operand for gcc/alpha

* src/atomic_ops/sysdeps/gcc/alpha.h (AO_compare_and_swap): Use "+m"
asm constraint for *addr instead of "=m" (because the value pointed by
addr is read and written by the code).

diff --git a/src/atomic_ops/sysdeps/gcc/alpha.h b/src/atomic_ops/sysdeps/gcc/alpha.h
index 61d0433..f90a86a 100644 (file)
--- a/src/atomic_ops/sysdeps/gcc/alpha.h
+++ b/src/atomic_ops/sysdeps/gcc/alpha.h
@@ -55,7 +55,7 @@ AO_compare_and_swap(volatile AO_t *addr,
                      "       stq_c %0,%1\n"
                      "       beq %0,1b\n"
                      "2:\n"
-                     :"=&r" (temp), "=m" (*addr), "=&r" (was_equal)
+                     : "=&r" (temp), "+m" (*addr), "=&r" (was_equal)
                      : "r" (new_val), "Ir" (old)
                      :"memory");
   return (int)was_equal;