On 10/12/20 15:32, Philippe Mathieu-Daudé wrote:
On 12/10/20 2:47 PM, marcandre.lur...@redhat.com wrote:
From: Marc-André Lureau <marcandre.lur...@redhat.com>
Since commit efc6c07 ("configure: Add a test for the minimum compiler
version"), QEMU explicitely depends on GCC >= 4.8.
(clang >= 3.4 advertizes itself as GCC >= 4.2 compatible and supports
__builtin_expect too)
Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
include/qemu/compiler.h | 4 ----
1 file changed, 4 deletions(-)
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index c76281f354..226ead6c90 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -44,10 +44,6 @@
#endif
#ifndef likely
-#if __GNUC__ < 3
-#define __builtin_expect(x, n) (x)
-#endif
-
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif
Trying with GCC 10:
warning: implicit declaration of function ‘likely’
[-Wimplicit-function-declaration]
Clang 10:
warning: implicit declaration of function 'likely' is invalid in C99
[-Wimplicit-function-declaration]
Shouldn't it becleaner to test in the configure script or Meson that
likely() and unlikely() are not defined, and define them here
unconditionally?
I think the point of the "#ifndef likely" is that some header file
(maybe something from Linux?) might be defining them unexpectedly. So
it's difficult to do the test at configure/meson time. I would also
tend towards removing the #ifndef and seeing if something breaks, but
not as part of this series.
Paolo
