1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "Swizzle.h"
8
9 #include <emmintrin.h>
10 #include <tmmintrin.h>
11
12 namespace mozilla::gfx {
13
14 template <bool aSwapRB>
15 void UnpackRowRGB24(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength);
16
17 template <bool aSwapRB>
UnpackRowRGB24_SSSE3(const uint8_t * aSrc,uint8_t * aDst,int32_t aLength)18 void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) {
19 // Because this implementation will read an additional 4 bytes of data that
20 // is ignored and masked over, we cannot use the accelerated version for the
21 // last 1-5 pixels (3-15 bytes remaining) to guarantee we don't access memory
22 // outside the buffer (we read in 16 byte chunks).
23 if (aLength < 6) {
24 UnpackRowRGB24<aSwapRB>(aSrc, aDst, aLength);
25 return;
26 }
27
28 // Because we are expanding, we can only process the data back to front in
29 // case we are performing this in place.
30 int32_t alignedRow = (aLength - 2) & ~3;
31 int32_t remainder = aLength - alignedRow;
32
33 const uint8_t* src = aSrc + alignedRow * 3;
34 uint8_t* dst = aDst + alignedRow * 4;
35
36 // Handle 2-5 remaining pixels.
37 UnpackRowRGB24<aSwapRB>(src, dst, remainder);
38
39 __m128i mask;
40 if (aSwapRB) {
41 mask = _mm_set_epi8(15, 9, 10, 11, 14, 6, 7, 8, 13, 3, 4, 5, 12, 0, 1, 2);
42 } else {
43 mask = _mm_set_epi8(15, 11, 10, 9, 14, 8, 7, 6, 13, 5, 4, 3, 12, 2, 1, 0);
44 }
45
46 __m128i alpha = _mm_set1_epi32(0xFF000000);
47
48 // Process all 4-pixel chunks as one vector.
49 src -= 4 * 3;
50 dst -= 4 * 4;
51 while (src >= aSrc) {
52 __m128i px = _mm_loadu_si128(reinterpret_cast<const __m128i*>(src));
53 px = _mm_shuffle_epi8(px, mask);
54 px = _mm_or_si128(px, alpha);
55 _mm_storeu_si128(reinterpret_cast<__m128i*>(dst), px);
56 src -= 4 * 3;
57 dst -= 4 * 4;
58 }
59 }
60
61 // Force instantiation of swizzle variants here.
62 template void UnpackRowRGB24_SSSE3<false>(const uint8_t*, uint8_t*, int32_t);
63 template void UnpackRowRGB24_SSSE3<true>(const uint8_t*, uint8_t*, int32_t);
64
65 } // namespace mozilla::gfx
66