[FFmpeg-devel] [PATCH 6/7] avcodec/x86/mpegvideoencdsp: speed up draw_edges_mmx by using memcpy()
Ramiro Polla
ramiro.polla at gmail.com
Sun Aug 18 23:13:25 EEST 2024
The mmx memory copy code is not nearly as efficient as memcpy(), which
would make draw_edges_mmx much slower than draw_edges_8_c.
Intel(R) Core(TM) i5-5300U CPU @ 2.30GHz:
before after
draw_edges_8_1724_4_mmx: 8697.2 8739.6 ( 1.00x)
draw_edges_8_1724_8_mmx: 10439.0 10548.4 ( 0.99x)
draw_edges_8_1724_16_mmx: 10687.5 10876.1 ( 0.98x)
draw_edges_128_407_4_mmx: 4252.5 3562.4 ( 1.19x)
draw_edges_128_407_8_mmx: 4561.7 3868.1 ( 1.18x)
draw_edges_128_407_16_mmx: 5505.7 4533.4 ( 1.21x)
draw_edges_1080_31_4_mmx: 1667.7 560.4 ( 2.98x)
draw_edges_1080_31_8_mmx: 2804.5 1232.1 ( 2.28x)
draw_edges_1080_31_16_mmx: 12478.5 3829.6 ( 3.26x)
draw_edges_1920_4_4_mmx: 2596.2 812.4 ( 3.20x)
draw_edges_1920_4_8_mmx: 8056.0 2964.4 ( 2.72x)
draw_edges_1920_4_16_mmx: 24628.7 6387.9 ( 3.86x)
---
libavcodec/x86/mpegvideoencdsp_init.c | 51 ++++++---------------------
1 file changed, 11 insertions(+), 40 deletions(-)
diff --git a/libavcodec/x86/mpegvideoencdsp_init.c b/libavcodec/x86/mpegvideoencdsp_init.c
index 503548e668..c30fa91175 100644
--- a/libavcodec/x86/mpegvideoencdsp_init.c
+++ b/libavcodec/x86/mpegvideoencdsp_init.c
@@ -166,46 +166,17 @@ static void draw_edges_mmx(uint8_t *buf, int wrap, int width, int height,
"r" (ptr + wrap * height));
}
- /* top and bottom (and hopefully also the corners) */
- if (sides & EDGE_TOP) {
- for (i = 0; i < h; i += 4) {
- ptr = buf - (i + 1) * wrap - w;
- __asm__ volatile (
- "1: \n\t"
- "movq (%1, %0), %%mm0 \n\t"
- "movq %%mm0, (%0) \n\t"
- "movq %%mm0, (%0, %2) \n\t"
- "movq %%mm0, (%0, %2, 2) \n\t"
- "movq %%mm0, (%0, %3) \n\t"
- "add $8, %0 \n\t"
- "cmp %4, %0 \n\t"
- "jb 1b \n\t"
- : "+r" (ptr)
- : "r" ((x86_reg) buf - (x86_reg) ptr - w),
- "r" ((x86_reg) - wrap), "r" ((x86_reg) - wrap * 3),
- "r" (ptr + width + 2 * w));
- }
- }
-
- if (sides & EDGE_BOTTOM) {
- for (i = 0; i < h; i += 4) {
- ptr = last_line + (i + 1) * wrap - w;
- __asm__ volatile (
- "1: \n\t"
- "movq (%1, %0), %%mm0 \n\t"
- "movq %%mm0, (%0) \n\t"
- "movq %%mm0, (%0, %2) \n\t"
- "movq %%mm0, (%0, %2, 2) \n\t"
- "movq %%mm0, (%0, %3) \n\t"
- "add $8, %0 \n\t"
- "cmp %4, %0 \n\t"
- "jb 1b \n\t"
- : "+r" (ptr)
- : "r" ((x86_reg) last_line - (x86_reg) ptr - w),
- "r" ((x86_reg) wrap), "r" ((x86_reg) wrap * 3),
- "r" (ptr + width + 2 * w));
- }
- }
+ /* top and bottom + corners */
+ buf -= w;
+ last_line = buf + (height - 1) * wrap;
+ if (sides & EDGE_TOP)
+ for (i = 0; i < h; i++)
+ // top
+ memcpy(buf - (i + 1) * wrap, buf, width + w + w);
+ if (sides & EDGE_BOTTOM)
+ for (i = 0; i < h; i++)
+ // bottom
+ memcpy(last_line + (i + 1) * wrap, last_line, width + w + w);
}
#endif /* HAVE_INLINE_ASM */
--
2.30.2
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