Am 08.10.2012 22:01, schrieb Michael S. Tsirkin:
On Wed, Oct 03, 2012 at 11:11:02PM +0200, Stefan Weil wrote:
The current check will give a wrong result for gcc-5.x with x < 4.
Using QEMU_GNUC_PREREQ is simpler and fixes that issue.
Signed-off-by: Stefan Weil <s...@weilnetz.de>
---
With current gcc versions (gcc-4.x) there is no problem.
Nevertheless, I suggest to fix this in stable versions, too.
Regards
Stefan Weil
ACK for stable tree.
qemu-barrier.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/qemu-barrier.h b/qemu-barrier.h
index 7e11197..16f0942 100644
--- a/qemu-barrier.h
+++ b/qemu-barrier.h
@@ -19,7 +19,7 @@
* mfence on 32 bit as well, e.g. if built with -march=pentium-m.
* However, on i386, there seem to be known bugs as recently as 4.3.
* */
-#if defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 4
+#if QEMU_GNUC_PREREQ(4, 4)
#define smp_mb() __sync_synchronize()
#else
#define smp_mb() asm volatile("lock; addl $0,0(%%esp) " ::: "memory")
--
1.7.10
My patch was incomplete: an include statement for compiler.h
is needed (see the patches which were applied to the same file in
git master.
Regards
Stefan Weil
