~560 → ~500 decicycles
This is following the comments from Michael in
https://ffmpeg.org/pipermail/ffmpeg-devel/2014-August/160599.html
Using 2 registers for accumulator didn't help. On the other hand,
some re-ordering between the movs and psadbw allowed going ~538 to ~500.
---
libavutil/x86/pixelutils.asm | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/libavutil/x86/pixelutils.asm b/libavutil/x86/pixelutils.asm
index 8ab0a18..15213d9 100644
--- a/libavutil/x86/pixelutils.asm
+++ b/libavutil/x86/pixelutils.asm
@@ -134,16 +134,20 @@ cglobal pixelutils_sad_16x16, 4,4,5, src1, stride1, src2,
stride2
%macro SAD_XMM_16x16 1
INIT_XMM sse2
cglobal pixelutils_sad_%1_16x16, 4,4,3, src1, stride1, src2, stride2
- pxor m2, m2
-%rep 8
- mov%1 m0, [src2q]
+ mov%1 m2, [src2q]
+ psadbw m2, [src1q]
mov%1 m1, [src2q + stride2q]
- psadbw m0, [src1q]
psadbw m1, [src1q + stride1q]
- paddw m2, m0
paddw m2, m1
+%rep 7
lea src1q, [src1q + 2*stride1q]
lea src2q, [src2q + 2*stride2q]
+ mov%1 m0, [src2q]
+ psadbw m0, [src1q]
+ mov%1 m1, [src2q + stride2q]
+ psadbw m1, [src1q + stride1q]
+ paddw m2, m0
+ paddw m2, m1
%endrep
movhlps m0, m2
paddw m2, m0
--
2.0.4
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