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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "Swizzle.h"
#include <immintrin.h>
#include <tmmintrin.h>
namespace mozilla::gfx {
template <bool aSwapRB>
void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength);
template <bool aSwapRB>
void UnpackRowRGB24_AVX2(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) {
// Because this implementation will read an additional 8 bytes of data that
// is ignored and masked over, we cannot use the accelerated version for the
// last 1-10 pixels (3-30 bytes remaining) to guarantee we don't access memory
// outside the buffer (we read in 32 byte chunks).
if (aLength < 11) {
UnpackRowRGB24_SSSE3<aSwapRB>(aSrc, aDst, aLength);
return;
}
// Because we are expanding, we can only process the data back to front in
// case we are performing this in place.
int32_t alignedRow = (aLength - 4) & ~7;
int32_t remainder = aLength - alignedRow;
const uint8_t* src = aSrc + alignedRow * 3;
uint8_t* dst = aDst + alignedRow * 4;
// Handle any 3-10 remaining pixels.
UnpackRowRGB24_SSSE3<aSwapRB>(src, dst, remainder);
// Used to shuffle the two final 32-bit words which we ignore into the last
// 32-bit word of each 128-bit lane, such that
// RGBR GBRG BRGB RGBR GBRG BRGB RGBR GBRG
// BRGB RGBR GBRG BRGB ZZZZ ZZZZ ZZZZ ZZZZ
// becomes
// RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ
// RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ
const __m256i discardMask = _mm256_set_epi32(7, 5, 4, 3, 6, 2, 1, 0);
// Used to shuffle 8-bit words within a 128-bit lane, such that we transform
// RGBR GBRG BRGB RGBR GBRG BRGB ZZZZ ZZZZ
// into
// RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ RGBZ
// or
// BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ BGRZ
const __m256i colorMask =
aSwapRB ? _mm256_set_epi8(15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 12, 0,
1, 2, 15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5,
12, 0, 1, 2)
: _mm256_set_epi8(15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 12, 2,
1, 0, 15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3,
12, 2, 1, 0);
// Used to transform RGBZ/BGRZ to RGBX/BGRX, or force the alpha opaque.
const __m256i alphaMask = _mm256_set1_epi32(0xFF000000);
// Process all 8-pixel chunks as one vector.
src -= 8 * 3;
dst -= 8 * 4;
while (src >= aSrc) {
__m256i px = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(src));
px = _mm256_permutevar8x32_epi32(px, discardMask);
px = _mm256_shuffle_epi8(px, colorMask);
px = _mm256_or_si256(px, alphaMask);
_mm256_storeu_si256(reinterpret_cast<__m256i*>(dst), px);
src -= 8 * 3;
dst -= 8 * 4;
}
}
// Force instantiation of swizzle variants here.
template void UnpackRowRGB24_AVX2<false>(const uint8_t*, uint8_t*, int32_t);
template void UnpackRowRGB24_AVX2<true>(const uint8_t*, uint8_t*, int32_t);
} // namespace mozilla::gfx