From: Ulrich Drepper <drepper@redhat.com>
Date: Fri, 22 Mar 2002 08:30:32 +0000 (+0000)
Subject: (MEMORY_BARRIER): Define as asm with memory as clobber.
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=191ab8540c06d18c7735f4b9230f06619f3750bd;p=thirdparty%2Fglibc.git

(MEMORY_BARRIER): Define as asm with memory as clobber.
---

diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h
index 8297c781c82..2159e70b772 100644
--- a/linuxthreads/internals.h
+++ b/linuxthreads/internals.h
@@ -398,11 +398,13 @@ static inline pthread_descr thread_self (void)
 }
 
 /* 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.  */
+   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()