Since we require GCC version 4.8 or newer now, we can be sure that
the builtin functions are always available on GCC. And for Clang,
we can check the availablility with __has_builtin instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 include/qemu/compiler.h   | 2 +-
 include/qemu/host-utils.h | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 8337361..261842b 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -121,7 +121,7 @@
 #define __has_builtin(x) 0 /* compatibility with non-clang compilers */
 #endif
 
-#if __has_builtin(__builtin_assume_aligned) || QEMU_GNUC_PREREQ(4, 7)
+#if __has_builtin(__builtin_assume_aligned) || !defined(__clang__)
 #define HAS_ASSUME_ALIGNED
 #endif
 
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 25ba3e8..0b3b79e 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -177,7 +177,7 @@ static inline int cto64(uint64_t val)
  */
 static inline int clrsb32(uint32_t val)
 {
-#if QEMU_GNUC_PREREQ(4, 7)
+#if __has_builtin(__builtin_clrsb) || !defined(__clang__)
     return __builtin_clrsb(val);
 #else
     return clz32(val ^ ((int32_t)val >> 1)) - 1;
@@ -193,7 +193,7 @@ static inline int clrsb32(uint32_t val)
  */
 static inline int clrsb64(uint64_t val)
 {
-#if QEMU_GNUC_PREREQ(4, 7)
+#if __has_builtin(__builtin_clrsbll) || !defined(__clang__)
     return __builtin_clrsbll(val);
 #else
     return clz64(val ^ ((int64_t)val >> 1)) - 1;
-- 
1.8.3.1

On 12/3/18 8:05 AM, Thomas Huth wrote:
> Since we require GCC version 4.8 or newer now, we can be sure that
> the builtin functions are always available on GCC. And for Clang,
> we can check the availablility with __has_builtin instead.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  include/qemu/compiler.h   | 2 +-
>  include/qemu/host-utils.h | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~