Clang MemorySanitizer builds define LIBYUV_ENABLE_ROWWIN and compile
row_win.cc and scale_win.cc instead of inline assembly. Two AVX-512
intrinsic patterns in those files are not modeled by LLVM MSan:
1. _mm512_mask_cvtepi32_storeu_epi8 and _mm512_mask_cvtepi64_storeu_epi8
lower to @llvm.x86.avx512.mask.pmov.db.mem.512 and
@llvm.x86.avx512.mask.pmov.qb.mem.512, which LLVM MSan handles as
unknown intrinsics without unpoisoning destination shadow memory.
Replace them in ARGBExtractAlphaRow_AVX512BW, ScaleAddCols1_AVX512BW,
and ScaleAddCols2_AVX512BW with _mm512_cvtepi32_epi8 /
_mm512_cvtepi64_epi8 followed by _mm_mask_storeu_epi8, which lowers
to @llvm.masked.store and still compiles to a single vpmovdb/vpmovqb
instruction.
2. ARGBCopyYToAlphaRow_AVX512BW loaded dst and blended the alpha channel
using _mm512_ternarylogic_epi32, which LLVM MSan does not model
bitwise and flags when any destination byte (such as the old alpha
channel) is uninitialized. Replace the load + vpternlogd + store in
both row_win.cc and row_gcc.cc with byte-masked stores
(_mm512_mask_storeu_epi8 / vmovdqu8 with mask 0x8888888888888888)
that write only the alpha bytes without reading dst.
Expand ARGBCopyAlpha, ARGBExtractAlpha, and ARGBCopyYToAlpha unit tests
into _Any, _Unaligned, _Invert, and _Opt variants and poison destination
buffers under MSan to catch unmodeled masked stores. Document MSan
AVX-512 intrinsic guidelines in GEMINI.md.
Test: out/msan/libyuv_unittest --gtest_filter=*Alpha*:*ScalePlaneBox_Any*
Bug: 578615529
Change-Id: I54ac4a5844aca6cfe3aa3445fa04b8221c610b35
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8672001
Commit-Queue: Frank Barchard <fbarchard@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
- MergeUVRow_SVE2: Interleaves U and V
- SplitUVRow_SVE2: De-interleaves UV
- InterpolateRow_SVE2: Bilinear row interpolation
- YUY2ToYRow_SVE2, YUY2ToUVRow_SVE2, UYVYToYRow_SVE2, UYVYToUVRow_SVE2
- HalfMergeUVRow_SVE2: 2:1 vertical averaging of U and V
OnePlus 15 with Qualcomm Snapdragon 8 Elite Gen 5 Oryon V3
Benchmark (1280x720 1000x) | SVE2 | NEON | Result
-------------------------------+--------+--------+------------------
TestInterpolatePlane | 119 ms | 164 ms | SVE2 is 1.38x win
TestInterpolatePlane_16 | 138 ms | 172 ms | SVE2 is 1.25x win
SplitUVPlane_Opt | 68 ms | 69 ms | SVE2 is 1.01x win
MergeUVPlane_Opt | 40 ms | 40 ms | Tied
SwapUVPlane_Opt | 72 ms | 72 ms | Tied
HalfMergeUVPlane_Opt | 50 ms | 50 ms | Tied
I420ToNV12_Opt | 25 ms | 26 ms | SVE2 is faster
I420ToNV21_Opt | 26 ms | 26 ms | Tied
YUY2ToNV12_Opt | 79 ms | 81 ms | SVE2 is faster
NV21ToNV12_Opt | 36 ms | 35 ms | Tied
Android420ToI420ToNV12_Opt | 53 ms | 53 ms | Tied
Android420ToI420ToNV21_Opt | 35 ms | 33 ms | NEON is faster
YUY2ToI420_Opt | 87 ms | 84 ms | NEON is faster
UYVYToI420_Opt | 87 ms | 83 ms | NEON is faster
YUY2ToI422_Opt | 101 ms | 97 ms | NEON is faster
UYVYToI422_Opt | 101 ms | 97 ms | NEON is faster
UYVYToNV12_Opt | 111 ms | 108 ms | NEON is faster
ARGBToNV21_Opt | 279 ms | 279 ms | Tied
ABGRToNV21_Opt | 279 ms | 280 ms | SVE2 is faster
ARGBToNV12_Opt | 285 ms | 280 ms | NEON is faster
ABGRToNV12_Opt | 284 ms | 281 ms | NEON is faster
Bug: 42280902
Change-Id: I53f633fe453f2853f7bc9fe17280e938912c4e8f
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8196068
Reviewed-by: Justin Green <greenjustin@google.com>
Commit-Queue: Frank Barchard <fbarchard@google.com>
- Implemented `I422ToRGB24Row_AVX2` and `I422ToRGB24Row_AVX512VBMI` in:
- `row_gcc.cc`: Inline assembly for GCC/Clang.
- `row_win.cc`: C++ intrinsics for MSVC (also verified with Clang).
Reduced width alignment requirement: changed from 32-pixel to 16-pixel
alignment in `convert_argb.cc` and `row_any.cc`. This allows the AVX2
path to be used for more common video resolutions.
```
I420ToRAW vs Rust on Icelake Xeon
Size I420ToRAW yuv420_to_rgb iterations
------- --------- --------------- ----------
640x480 57 us 77.377 µs/iter 3000
1280x720 170 us 221.671 µs/iter 1000
1920x1080 396 us 494.324 µs/iter 500
3840x2160 2040 us 2357 µs/iter 200
```
Bug: 42280902
Change-Id: I07c0505c95410ea16a6218c858844791a11ef073
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/7908323
Reviewed-by: Wan-Teh Chang <wtc@google.com>
Reviewed-by: richard winterton <rrwinterton@gmail.com>
Commit-Queue: Frank Barchard <fbarchard@google.com>
