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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
#include "Swizzle.h"
#include <emmintrin.h>
#include <tmmintrin.h>
namespace mozilla::gfx {
template <bool aSwapRB>
void UnpackRowRGB24(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength);
template <bool aSwapRB>
void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) {
// Because this implementation will read an additional 4 bytes of data that
// is ignored and masked over, we cannot use the accelerated version for the
// last 1-5 pixels (3-15 bytes remaining) to guarantee we don't access memory
// outside the buffer (we read in 16 byte chunks).
if (aLength < 6) {
UnpackRowRGB24<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 - 2) & ~3;
int32_t remainder = aLength - alignedRow;
const uint8_t* src = aSrc + alignedRow * 3;
uint8_t* dst = aDst + alignedRow * 4;
// Handle 2-5 remaining pixels.
UnpackRowRGB24<aSwapRB>(src, dst, remainder);
__m128i mask;
if (aSwapRB) {
mask = _mm_set_epi8(15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 12, 0, 1, 2);
} else {
mask = _mm_set_epi8(15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 12, 2, 1, 0);
}
__m128i alpha = _mm_set1_epi32(0xFF000000);
// Process all 4-pixel chunks as one vector.
src -= 4 * 3;
dst -= 4 * 4;
while (src >= aSrc) {
__m128i px = _mm_loadu_si128(reinterpret_cast<const __m128i*>(src));
px = _mm_shuffle_epi8(px, mask);
px = _mm_or_si128(px, alpha);
_mm_storeu_si128(reinterpret_cast<__m128i*>(dst), px);
src -= 4 * 3;
dst -= 4 * 4;
}
}
// Force instantiation of swizzle variants here.
template void UnpackRowRGB24_SSSE3<false>(const uint8_t*, uint8_t*, int32_t);
template void UnpackRowRGB24_SSSE3<true>(const uint8_t*, uint8_t*, int32_t);
} // namespace mozilla::gfx