linux-atomic.c (__sync_val_compare_and_swap_4): Return actual_oldval.

	* config/pa/linux-atomic.c (__sync_val_compare_and_swap_4): Return
	actual_oldval.  Use __builtin_expect.
	(SUBWORD_VAL_CAS): Likewise.

From-SVN: r165339

gcc/ChangeLog

+2010-10-11  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+	* config/pa/linux-atomic.c (__sync_val_compare_and_swap_4): Return
+	actual_oldval.  Use __builtin_expect.
+	(SUBWORD_VAL_CAS): Likewise.
+
 2010-10-11  Nathan Froyd  <froydnj@codesourcery.com>
 
 	* recog.c (nonmemory_operand): Call immediate_operand for

gcc/config/pa/linux-atomic.c

@@ -191,13 +191,13 @@ __sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval)
     {
       actual_oldval = *ptr;
 
-      if (oldval != actual_oldval)
+      if (__builtin_expect (oldval != actual_oldval, 0))
 	return actual_oldval;
 
       fail = __kernel_cmpxchg (actual_oldval, newval, ptr);
   
-      if (!fail)
-	return oldval;
+      if (__builtin_expect (!fail, 1))
+	return actual_oldval;
     }
 }
 
@@ -216,8 +216,9 @@ __sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval)
       {									\
 	actual_oldval = *wordptr;					\
 									\
-	if (((actual_oldval & mask) >> shift) != (unsigned int) oldval)	\
-          return (actual_oldval & mask) >> shift;			\
+	if (__builtin_expect (((actual_oldval & mask) >> shift)		\
+			      != (unsigned int) oldval, 0))		\
+	  return (actual_oldval & mask) >> shift;			\
 									\
 	actual_newval = (actual_oldval & ~mask)				\
 			| (((unsigned int) newval << shift) & mask);	\
@@ -225,8 +226,8 @@ __sync_val_compare_and_swap_4 (int *ptr, int oldval, int newval)
 	fail = __kernel_cmpxchg (actual_oldval, actual_newval,		\
 				 wordptr);				\
 									\
-	if (!fail)							\
-	  return oldval;						\
+	if (__builtin_expect (!fail, 1))				\
+	  return (actual_oldval & mask) >> shift;			\
       }									\
   }