1c864a9d15
We use a standard set of strict compiler warnings with Clang and GCC to continuously test and maintain C89 conformance in the libjpeg API code. However, SIMD extensions need not comply with that. The AltiVec code specifically uses some C99isms, so disable -Wc99-extensions and -Wpedantic in the scope of that code. Also disable -Wshadow, because I'm too lazy to fix the TRANSPOSE() macro. Also use #ifdef __BIG_ENDIAN__ and #if defined(__BIG_ENDIAN__) instead of #if __BIG_ENDIAN__
229 lines
8.6 KiB
C
229 lines
8.6 KiB
C
/*
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* AltiVec optimizations for libjpeg-turbo
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*
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* Copyright (C) 2014-2015, 2024, D. R. Commander. All Rights Reserved.
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* Copyright (C) 2014, Jay Foad. All Rights Reserved.
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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/* This file is included by jcgray-altivec.c */
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void jsimd_rgb_gray_convert_altivec(JDIMENSION img_width, JSAMPARRAY input_buf,
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JSAMPIMAGE output_buf,
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JDIMENSION output_row, int num_rows)
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{
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JSAMPROW inptr, outptr;
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int pitch = img_width * RGB_PIXELSIZE, num_cols;
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#ifdef __BIG_ENDIAN__
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int offset;
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unsigned char __attribute__((aligned(16))) tmpbuf[RGB_PIXELSIZE * 16];
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#endif
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__vector unsigned char rgb0, rgb1 = { 0 }, rgb2 = { 0 },
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rgbg0, rgbg1, rgbg2, rgbg3, y;
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#if defined(__BIG_ENDIAN__) || RGB_PIXELSIZE == 4
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__vector unsigned char rgb3 = { 0 };
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#endif
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#if defined(__BIG_ENDIAN__) && RGB_PIXELSIZE == 4
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__vector unsigned char rgb4 = { 0 };
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#endif
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__vector short rg0, rg1, rg2, rg3, bg0, bg1, bg2, bg3;
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__vector unsigned short yl, yh;
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__vector int y0, y1, y2, y3;
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/* Constants */
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__vector short pw_f0299_f0337 = { __4X2(F_0_299, F_0_337) },
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pw_f0114_f0250 = { __4X2(F_0_114, F_0_250) };
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__vector int pd_onehalf = { __4X(ONE_HALF) };
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__vector unsigned char pb_zero = { __16X(0) },
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#ifdef __BIG_ENDIAN__
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shift_pack_index =
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{ 0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29 };
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#else
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shift_pack_index =
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{ 2, 3, 6, 7, 10, 11, 14, 15, 18, 19, 22, 23, 26, 27, 30, 31 };
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#endif
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while (--num_rows >= 0) {
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inptr = *input_buf++;
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outptr = output_buf[0][output_row];
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output_row++;
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for (num_cols = pitch; num_cols > 0;
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num_cols -= RGB_PIXELSIZE * 16, inptr += RGB_PIXELSIZE * 16,
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outptr += 16) {
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#ifdef __BIG_ENDIAN__
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/* Load 16 pixels == 48 or 64 bytes */
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offset = (size_t)inptr & 15;
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if (offset) {
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__vector unsigned char unaligned_shift_index;
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int bytes = num_cols + offset;
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if (bytes < (RGB_PIXELSIZE + 1) * 16 && (bytes & 15)) {
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/* Slow path to prevent buffer overread. Since there is no way to
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* read a partial AltiVec register, overread would occur on the last
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* chunk of the last image row if the right edge is not on a 16-byte
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* boundary. It could also occur on other rows if the bytes per row
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* is low enough. Since we can't determine whether we're on the last
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* image row, we have to assume every row is the last.
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*/
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memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16));
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rgb0 = vec_ld(0, tmpbuf);
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rgb1 = vec_ld(16, tmpbuf);
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rgb2 = vec_ld(32, tmpbuf);
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#if RGB_PIXELSIZE == 4
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rgb3 = vec_ld(48, tmpbuf);
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#endif
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} else {
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/* Fast path */
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rgb0 = vec_ld(0, inptr);
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if (bytes > 16)
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rgb1 = vec_ld(16, inptr);
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if (bytes > 32)
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rgb2 = vec_ld(32, inptr);
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if (bytes > 48)
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rgb3 = vec_ld(48, inptr);
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#if RGB_PIXELSIZE == 4
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if (bytes > 64)
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rgb4 = vec_ld(64, inptr);
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#endif
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unaligned_shift_index = vec_lvsl(0, inptr);
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rgb0 = vec_perm(rgb0, rgb1, unaligned_shift_index);
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rgb1 = vec_perm(rgb1, rgb2, unaligned_shift_index);
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rgb2 = vec_perm(rgb2, rgb3, unaligned_shift_index);
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#if RGB_PIXELSIZE == 4
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rgb3 = vec_perm(rgb3, rgb4, unaligned_shift_index);
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#endif
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}
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} else {
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if (num_cols < RGB_PIXELSIZE * 16 && (num_cols & 15)) {
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/* Slow path */
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memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16));
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rgb0 = vec_ld(0, tmpbuf);
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rgb1 = vec_ld(16, tmpbuf);
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rgb2 = vec_ld(32, tmpbuf);
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#if RGB_PIXELSIZE == 4
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rgb3 = vec_ld(48, tmpbuf);
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#endif
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} else {
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/* Fast path */
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rgb0 = vec_ld(0, inptr);
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if (num_cols > 16)
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rgb1 = vec_ld(16, inptr);
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if (num_cols > 32)
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rgb2 = vec_ld(32, inptr);
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#if RGB_PIXELSIZE == 4
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if (num_cols > 48)
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rgb3 = vec_ld(48, inptr);
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#endif
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}
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}
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#else
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/* Little endian */
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rgb0 = vec_vsx_ld(0, inptr);
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if (num_cols > 16)
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rgb1 = vec_vsx_ld(16, inptr);
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if (num_cols > 32)
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rgb2 = vec_vsx_ld(32, inptr);
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#if RGB_PIXELSIZE == 4
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if (num_cols > 48)
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rgb3 = vec_vsx_ld(48, inptr);
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#endif
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#endif
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#if RGB_PIXELSIZE == 3
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/* rgb0 = R0 G0 B0 R1 G1 B1 R2 G2 B2 R3 G3 B3 R4 G4 B4 R5
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* rgb1 = G5 B5 R6 G6 B6 R7 G7 B7 R8 G8 B8 R9 G9 B9 Ra Ga
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* rgb2 = Ba Rb Gb Bb Rc Gc Bc Rd Gd Bd Re Ge Be Rf Gf Bf
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*
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* rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3
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* rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7
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* rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb
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* rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf
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*/
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rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX0);
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rgbg1 = vec_perm(rgb0, rgb1, (__vector unsigned char)RGBG_INDEX1);
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rgbg2 = vec_perm(rgb1, rgb2, (__vector unsigned char)RGBG_INDEX2);
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rgbg3 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX3);
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#else
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/* rgb0 = R0 G0 B0 X0 R1 G1 B1 X1 R2 G2 B2 X2 R3 G3 B3 X3
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* rgb1 = R4 G4 B4 X4 R5 G5 B5 X5 R6 G6 B6 X6 R7 G7 B7 X7
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* rgb2 = R8 G8 B8 X8 R9 G9 B9 X9 Ra Ga Ba Xa Rb Gb Bb Xb
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* rgb3 = Rc Gc Bc Xc Rd Gd Bd Xd Re Ge Be Xe Rf Gf Bf Xf
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*
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* rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3
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* rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7
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* rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb
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* rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf
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*/
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rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX);
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rgbg1 = vec_perm(rgb1, rgb1, (__vector unsigned char)RGBG_INDEX);
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rgbg2 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX);
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rgbg3 = vec_perm(rgb3, rgb3, (__vector unsigned char)RGBG_INDEX);
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#endif
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/* rg0 = R0 G0 R1 G1 R2 G2 R3 G3
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* bg0 = B0 G0 B1 G1 B2 G2 B3 G3
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* ...
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*
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* NOTE: We have to use vec_merge*() here because vec_unpack*() doesn't
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* support unsigned vectors.
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*/
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rg0 = (__vector signed short)VEC_UNPACKHU(rgbg0);
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bg0 = (__vector signed short)VEC_UNPACKLU(rgbg0);
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rg1 = (__vector signed short)VEC_UNPACKHU(rgbg1);
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bg1 = (__vector signed short)VEC_UNPACKLU(rgbg1);
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rg2 = (__vector signed short)VEC_UNPACKHU(rgbg2);
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bg2 = (__vector signed short)VEC_UNPACKLU(rgbg2);
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rg3 = (__vector signed short)VEC_UNPACKHU(rgbg3);
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bg3 = (__vector signed short)VEC_UNPACKLU(rgbg3);
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/* (Original)
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* Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
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*
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* (This implementation)
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* Y = 0.29900 * R + 0.33700 * G + 0.11400 * B + 0.25000 * G
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*/
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/* Calculate Y values */
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y0 = vec_msums(rg0, pw_f0299_f0337, pd_onehalf);
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y1 = vec_msums(rg1, pw_f0299_f0337, pd_onehalf);
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y2 = vec_msums(rg2, pw_f0299_f0337, pd_onehalf);
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y3 = vec_msums(rg3, pw_f0299_f0337, pd_onehalf);
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y0 = vec_msums(bg0, pw_f0114_f0250, y0);
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y1 = vec_msums(bg1, pw_f0114_f0250, y1);
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y2 = vec_msums(bg2, pw_f0114_f0250, y2);
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y3 = vec_msums(bg3, pw_f0114_f0250, y3);
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/* Clever way to avoid 4 shifts + 2 packs. This packs the high word from
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* each dword into a new 16-bit vector, which is the equivalent of
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* descaling the 32-bit results (right-shifting by 16 bits) and then
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* packing them.
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*/
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yl = vec_perm((__vector unsigned short)y0, (__vector unsigned short)y1,
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shift_pack_index);
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yh = vec_perm((__vector unsigned short)y2, (__vector unsigned short)y3,
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shift_pack_index);
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y = vec_pack(yl, yh);
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vec_st(y, 0, outptr);
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}
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}
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}
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