Frank Barchard 1ddb18fb6b [libyuv] AVX512, NEON, WASM and RVV alpha copy and mirror rows
1275x1650 (US Letter 150 DPI, 1000 iterations) speedup:

CPU            ARGBExtractAlpha ARGBCopyYToAlpha ARGBMirror RGB24Mirror
-----------------------------------------------------------------------
Intel Granite Rapids      1.00x            1.00x      1.00x       1.04x
Intel Emerald Rapids      1.01x            0.97x      1.03x       1.07x
Intel Sapphire Rapids     0.97x            1.01x      1.08x       1.26x
Intel Ice Lake            0.99x            1.02x      0.97x       1.08x
Intel Skylake-X           1.04x            1.03x      1.01x          NA
Intel Haswell                NA               NA         NA          NA
AMD Turin (Zen 5)         1.01x            1.10x      1.25x       1.31x
AMD Genoa (Zen 4)         0.97x            1.04x      1.09x       1.42x
AMD Milan (Zen 3)            NA               NA         NA          NA
AMD Rome (Zen 2)             NA               NA         NA          NA
NVIDIA Grace (V2)         1.57x            2.51x         NA          NA
Google Axion 2            1.12x            3.17x         NA          NA
Ampere Siryn              1.06x            1.70x         NA          NA
ARM Neoverse-N1           1.49x            2.01x         NA          NA
Google Axion (Maple)      1.47x            2.03x         NA          NA
ARM Cortex-A53            1.06x            1.69x         NA          NA

Add AVX512BW ARGBExtractAlphaRow, ARGBCopyYToAlphaRow and
ARGBMirrorRow, and AVX512VBMI RGB24MirrorRow, in row_gcc.cc and as
intrinsics in row_win.cc. They are x64 only. The remainder is done
with a k-mask (bzhi) zero-masked load and a masked store, so they
handle any width without an Any wrapper and never access memory
outside the row.

RGB24MirrorRow_AVX512VBMI loads and stores 3 full zmm vectors per
64 pixels using 3 vpermi2b. The one output byte that comes from the
third input vector is merged with a masked vpbroadcastb. The 1 to 63
pixel tail rebases the same tables by 192 - 3 * r; indices >= 128 are
taken from the third vector with vpmovb2m and a masked vpermb.

Add ARGBCopyYToAlphaRow_NEON for Arm 32 bit (vld4 + vst4) and
AArch64 (zip + sli), and rewrite AArch64 ARGBExtractAlphaRow_NEON
with ldp + uzp2. Both prefetch source and destination, which is
2.5x faster on Neoverse-N1 and 1.2x to 1.5x faster on Cortex-A53
for 1280x720. Add WASM SIMD ARGBExtractAlphaRow and
ARGBCopyYToAlphaRow, using a swizzle table for CopyYToAlpha. Rework
the RVV versions to use unit stride loads with vnsrl and vzext.vf4.


R=rrwinterton@gmail.com

Bug: None
Change-Id: I436f27d70a3db0a2b176c91eb789a9491133cfcb
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8523531
Reviewed-by: richard winterton <rrwinterton@gmail.com>
Commit-Queue: Frank Barchard <fbarchard@google.com>
2026-10-07 12:44:53 -07:00
..
libyuv [libyuv] AVX512, NEON, WASM and RVV alpha copy and mirror rows 2026-10-07 12:44:53 -07:00
libyuv.h libyuv.h: Add scale_rgb.h and remove scale_row.h 2026-08-26 19:06:22 -07:00