Update.

2002-03-22  Ulrich Drepper  <drepper@redhat.com>

	* internals.h (MEMORY_BARRIER): Define as asm with memory as clobber.

diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog
index 8ba4345..18c86f5 100644 (file)
--- a/linuxthreads/ChangeLog
+++ b/linuxthreads/ChangeLog
@@ -1,3 +1,7 @@
+2002-03-22  Ulrich Drepper  <drepper@redhat.com>
+
+       * internals.h (MEMORY_BARRIER): Define as asm with memory as clobber.
+
 2002-03-17  Andreas Jaeger  <aj@suse.de>
 
        * sysdeps/i386/pt-machine.h: Add testandset and __compare_and_swap

diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h
index 8fef62f..45a73ad 100644 (file)
--- a/linuxthreads/internals.h
+++ b/linuxthreads/internals.h
@@ -193,12 +193,14 @@ static inline int nonexisting_handle(pthread_handle h, pthread_t id)
 #define THREAD_STACK_START_ADDRESS  __pthread_initial_thread_bos
 #endif
 
-/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the architecture
-   doesn't need a memory barrier instruction (e.g. Intel x86).  Some
-   architectures distinguish between full, read and write barriers.  */
+/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the
+   architecture doesn't need a memory barrier instruction (e.g. Intel
+   x86).  Still we need the compiler to respect the barrier and emit
+   all outstanding operations which modify memory.  Some architectures
+   distinguish between full, read and write barriers.  */
 
 #ifndef MEMORY_BARRIER
-#define MEMORY_BARRIER()
+#define MEMORY_BARRIER() asm ("" : : : "memory")
 #endif
 #ifndef READ_MEMORY_BARRIER
 #define READ_MEMORY_BARRIER() MEMORY_BARRIER()