[FFmpeg-devel] [PATCH 1/2] avutil/intmath: use AV_HAS_BUILTIN to detect builtin availability

[Kacper Michajłow]

Fixes use of bultins on clang x86_64-pc-windows-msvc which does not
define any __GNUC__. Also on other targets __GNUC__ is defined to 4 by
default, so any feature testing based on version is not really valid.

Signed-off-by: Kacper Michajłow <kasper93 at gmail.com>
---
 libavutil/intmath.h     | 12 +++++-------
 libavutil/x86/intmath.h |  4 ++--
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/libavutil/intmath.h b/libavutil/intmath.h
index 52e11a8d5f..b177a848c6 100644
--- a/libavutil/intmath.h
+++ b/libavutil/intmath.h
@@ -35,7 +35,7 @@
 #endif
 
 #if HAVE_FAST_CLZ
-#if AV_GCC_VERSION_AT_LEAST(3,4)
+#if AV_GCC_VERSION_AT_LEAST(3,4) || AV_HAS_BUILTIN(__builtin_clz)
 #ifndef ff_log2
 #   define ff_log2(x) (31 - __builtin_clz((x)|1))
 #   ifndef ff_log2_16bit
@@ -90,18 +90,16 @@ static av_always_inline av_const int ff_log2_16bit_c(unsigned int v)
  */
 
 #if HAVE_FAST_CLZ
-#if AV_GCC_VERSION_AT_LEAST(3,4)
-#ifndef ff_ctz
+#if !defined(ff_ctz) && (AV_GCC_VERSION_AT_LEAST(3,4) || AV_HAS_BUILTIN(__builtin_ctz))
 #define ff_ctz(v) __builtin_ctz(v)
 #endif
-#ifndef ff_ctzll
+#if !defined(ff_ctzll) && (AV_GCC_VERSION_AT_LEAST(3,4) || AV_HAS_BUILTIN(__builtin_ctzll))
 #define ff_ctzll(v) __builtin_ctzll(v)
 #endif
-#ifndef ff_clz
+#if !defined(ff_clz) && (AV_GCC_VERSION_AT_LEAST(3,4) || AV_HAS_BUILTIN(__builtin_clz))
 #define ff_clz(v) __builtin_clz(v)
 #endif
 #endif
-#endif
 
 #ifndef ff_ctz
 #define ff_ctz ff_ctz_c
@@ -154,7 +152,7 @@ static av_always_inline av_const unsigned ff_clz_c(unsigned x)
 }
 #endif
 
-#if AV_GCC_VERSION_AT_LEAST(3,4)
+#if AV_GCC_VERSION_AT_LEAST(3,4) || AV_HAS_BUILTIN(__builtin_parity)
 #ifndef av_parity
 #define av_parity __builtin_parity
 #endif
diff --git a/libavutil/x86/intmath.h b/libavutil/x86/intmath.h
index 4893a1f1b4..030ded6b6f 100644
--- a/libavutil/x86/intmath.h
+++ b/libavutil/x86/intmath.h
@@ -66,7 +66,7 @@ static av_always_inline av_const int ff_ctzll_x86(long long v)
 
 #endif /* HAVE_FAST_CLZ */
 
-#if defined(__GNUC__)
+#if defined(__GNUC__) || defined(__clang__)
 
 /* Our generic version of av_popcount is faster than GCC's built-in on
  * CPUs that don't support the popcnt instruction.
@@ -81,7 +81,7 @@ static av_always_inline av_const int ff_ctzll_x86(long long v)
 
 #if defined(__BMI2__)
 
-#if AV_GCC_VERSION_AT_LEAST(5,1)
+#if AV_GCC_VERSION_AT_LEAST(5,1) || AV_HAS_BUILTIN(__builtin_ia32_bzhi_si)
 #if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
 #define av_zero_extend av_zero_extend_bmi2
 static av_always_inline av_const unsigned av_zero_extend_bmi2(unsigned a, unsigned p)
-- 
2.45.1