commit 958dad705a8c2c191e4352547fc9950c4feaa9fb
author Chris Dearman <chris@mips.com> Mon Jul 23 17:30:04 2012 -0700
committer Elliott Hughes <enh@google.com> Tue Jul 24 13:56:38 2012 -0700
tree 1c73bc42b0aafd48ea3b8317427939f3d4b970b7
parent 344aca8ced2522074f799439e201226377d02dba

Fix implementation of generic atomic operations

Change-Id: Ie1ea5aacc561e2d6d40125d2952ed0e9116b7b0d

libc/private/bionic_atomic_gcc_builtin.h

diff --git a/libc/private/bionic_atomic_gcc_builtin.h b/libc/private/bionic_atomic_gcc_builtin.h
index e7c5761..2919f7f 100644
--- a/libc/private/bionic_atomic_gcc_builtin.h
+++ b/libc/private/bionic_atomic_gcc_builtin.h
@@ -31,18 +31,17 @@
 __bionic_cmpxchg(int32_t old_value, int32_t new_value, volatile int32_t* ptr)
 {
     /* We must return 0 on success */
-    return __sync_bool_compare_and_swap(ptr, old_value, new_value) == 0;
+    return __sync_val_compare_and_swap(ptr, old_value, new_value) != old_value;
 }
 
 __ATOMIC_INLINE__ int32_t
 __bionic_swap(int32_t new_value, volatile int32_t* ptr)
 {
-    int32_t prev;
+    int32_t old_value;
     do {
-        prev = *ptr;
-        status = __sync_val_compare_and_swap(ptr, prev, new_value);
-    } while (status == 0);
-    return prev;
+        old_value = *ptr;
+    } while (__sync_val_compare_and_swap(ptr, old_value, new_value) != old_value);
+    return old_value;
 }
 
 __ATOMIC_INLINE__ int32_t