[FFmpeg-devel] [PATCH] avutil/x86/intmath: remove inline asm implementations for clip functions

James Almer jamrial at gmail.com
Mon Jun 2 21:41:33 EEST 2025


GCC/Clang is smart enough to emit minss/maxss the same way as these functions.
The only theoretical benefit was in x86_32, where x87 floats are used, but the
penalty of making the clipping opaque to the compiler's scheduler plus moving
values from mmx regs to xmm and back will offset any potential speedup.
x86_32 builds targetting anything made in the last two decades and a half
should use -msse -mfp=sse anyway.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavutil/x86/intmath.h | 62 -----------------------------------------
 1 file changed, 62 deletions(-)

diff --git a/libavutil/x86/intmath.h b/libavutil/x86/intmath.h
index 4893a1f1b4..735945ca95 100644
--- a/libavutil/x86/intmath.h
+++ b/libavutil/x86/intmath.h
@@ -114,68 +114,6 @@ static av_always_inline av_const unsigned av_zero_extend_bmi2(unsigned a, unsign
 
 #endif /* __BMI2__ */
 
-#if defined(__SSE2__) && !defined(__INTEL_COMPILER)
-
-#define av_clipd av_clipd_sse2
-static av_always_inline av_const double av_clipd_sse2(double a, double amin, double amax)
-{
-#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
-    if (amin > amax) abort();
-#endif
-    __asm__ ("maxsd %1, %0 \n\t"
-             "minsd %2, %0 \n\t"
-             : "+&x"(a) : "xm"(amin), "xm"(amax));
-    return a;
-}
-
-#endif /* __SSE2__ */
-
-#if defined(__SSE__) && !defined(__INTEL_COMPILER)
-
-#define av_clipf av_clipf_sse
-static av_always_inline av_const float av_clipf_sse(float a, float amin, float amax)
-{
-#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
-    if (amin > amax) abort();
-#endif
-    __asm__ ("maxss %1, %0 \n\t"
-             "minss %2, %0 \n\t"
-             : "+&x"(a) : "xm"(amin), "xm"(amax));
-    return a;
-}
-
-#endif /* __SSE__ */
-
-#if defined(__AVX__) && !defined(__INTEL_COMPILER)
-
-#undef av_clipd
-#define av_clipd av_clipd_avx
-static av_always_inline av_const double av_clipd_avx(double a, double amin, double amax)
-{
-#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
-    if (amin > amax) abort();
-#endif
-    __asm__ ("vmaxsd %1, %0, %0 \n\t"
-             "vminsd %2, %0, %0 \n\t"
-             : "+&x"(a) : "xm"(amin), "xm"(amax));
-    return a;
-}
-
-#undef av_clipf
-#define av_clipf av_clipf_avx
-static av_always_inline av_const float av_clipf_avx(float a, float amin, float amax)
-{
-#if defined(ASSERT_LEVEL) && ASSERT_LEVEL >= 2
-    if (amin > amax) abort();
-#endif
-    __asm__ ("vmaxss %1, %0, %0 \n\t"
-             "vminss %2, %0, %0 \n\t"
-             : "+&x"(a) : "xm"(amin), "xm"(amax));
-    return a;
-}
-
-#endif /* __AVX__ */
-
 #endif /* __GNUC__ */
 
 #endif /* AVUTIL_X86_INTMATH_H */
-- 
2.49.0



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