1 /* 2 * AltiVec optimizations for libjpeg-turbo 3 * 4 * Copyright (C) 2014-2015, D. R. Commander. All Rights Reserved. 5 * Copyright (C) 2014, Jay Foad. All Rights Reserved. 6 * 7 * This software is provided 'as-is', without any express or implied 8 * warranty. In no event will the authors be held liable for any damages 9 * arising from the use of this software. 10 * 11 * Permission is granted to anyone to use this software for any purpose, 12 * including commercial applications, and to alter it and redistribute it 13 * freely, subject to the following restrictions: 14 * 15 * 1. The origin of this software must not be misrepresented; you must not 16 * claim that you wrote the original software. If you use this software 17 * in a product, an acknowledgment in the product documentation would be 18 * appreciated but is not required. 19 * 2. Altered source versions must be plainly marked as such, and must not be 20 * misrepresented as being the original software. 21 * 3. This notice may not be removed or altered from any source distribution. 22 */ 23 24 /* This file is included by jccolor-altivec.c */ 25 26 27 void jsimd_rgb_ycc_convert_altivec (JDIMENSION img_width, JSAMPARRAY input_buf, 28 JSAMPIMAGE output_buf, 29 JDIMENSION output_row, int num_rows) 30 { 31 JSAMPROW inptr, outptr0, outptr1, outptr2; 32 int pitch = img_width * RGB_PIXELSIZE, num_cols; 33 #if __BIG_ENDIAN__ 34 int offset; 35 #endif 36 unsigned char __attribute__((aligned(16))) tmpbuf[RGB_PIXELSIZE * 16]; 37 38 __vector unsigned char rgb0, rgb1 = {0}, rgb2 = {0}, 39 rgbg0, rgbg1, rgbg2, rgbg3, y, cb, cr; 40 #if __BIG_ENDIAN__ || RGB_PIXELSIZE == 4 41 __vector unsigned char rgb3 = {0}; 42 #endif 43 #if __BIG_ENDIAN__ && RGB_PIXELSIZE == 4 44 __vector unsigned char rgb4 = {0}; 45 #endif 46 __vector short rg0, rg1, rg2, rg3, bg0, bg1, bg2, bg3; 47 __vector unsigned short yl, yh, crl, crh, cbl, cbh; 48 __vector int y0, y1, y2, y3, cr0, cr1, cr2, cr3, cb0, cb1, cb2, cb3; 49 50 /* Constants */ 51 __vector short pw_f0299_f0337 = { __4X2(F_0_299, F_0_337) }, 52 pw_f0114_f0250 = { __4X2(F_0_114, F_0_250) }, 53 pw_mf016_mf033 = { __4X2(-F_0_168, -F_0_331) }, 54 pw_mf008_mf041 = { __4X2(-F_0_081, -F_0_418) }; 55 __vector unsigned short pw_f050_f000 = { __4X2(F_0_500, 0) }; 56 __vector int pd_onehalf = { __4X(ONE_HALF) }, 57 pd_onehalfm1_cj = { __4X(ONE_HALF - 1 + (CENTERJSAMPLE << SCALEBITS)) }; 58 __vector unsigned char pb_zero = { __16X(0) }, 59 #if __BIG_ENDIAN__ 60 shift_pack_index = {0,1,4,5,8,9,12,13,16,17,20,21,24,25,28,29}; 61 #else 62 shift_pack_index = {2,3,6,7,10,11,14,15,18,19,22,23,26,27,30,31}; 63 #endif 64 65 while (--num_rows >= 0) { 66 inptr = *input_buf++; 67 outptr0 = output_buf[0][output_row]; 68 outptr1 = output_buf[1][output_row]; 69 outptr2 = output_buf[2][output_row]; 70 output_row++; 71 72 for (num_cols = pitch; num_cols > 0; 73 num_cols -= RGB_PIXELSIZE * 16, inptr += RGB_PIXELSIZE * 16, 74 outptr0 += 16, outptr1 += 16, outptr2 += 16) { 75 76 #if __BIG_ENDIAN__ 77 /* Load 16 pixels == 48 or 64 bytes */ 78 offset = (size_t)inptr & 15; 79 if (offset) { 80 __vector unsigned char unaligned_shift_index; 81 int bytes = num_cols + offset; 82 83 if (bytes < (RGB_PIXELSIZE + 1) * 16 && (bytes & 15)) { 84 /* Slow path to prevent buffer overread. Since there is no way to 85 * read a partial AltiVec register, overread would occur on the last 86 * chunk of the last image row if the right edge is not on a 16-byte 87 * boundary. It could also occur on other rows if the bytes per row 88 * is low enough. Since we can't determine whether we're on the last 89 * image row, we have to assume every row is the last. 90 */ 91 memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16)); 92 rgb0 = vec_ld(0, tmpbuf); 93 rgb1 = vec_ld(16, tmpbuf); 94 rgb2 = vec_ld(32, tmpbuf); 95 #if RGB_PIXELSIZE == 4 96 rgb3 = vec_ld(48, tmpbuf); 97 #endif 98 } else { 99 /* Fast path */ 100 rgb0 = vec_ld(0, inptr); 101 if (bytes > 16) 102 rgb1 = vec_ld(16, inptr); 103 if (bytes > 32) 104 rgb2 = vec_ld(32, inptr); 105 if (bytes > 48) 106 rgb3 = vec_ld(48, inptr); 107 #if RGB_PIXELSIZE == 4 108 if (bytes > 64) 109 rgb4 = vec_ld(64, inptr); 110 #endif 111 unaligned_shift_index = vec_lvsl(0, inptr); 112 rgb0 = vec_perm(rgb0, rgb1, unaligned_shift_index); 113 rgb1 = vec_perm(rgb1, rgb2, unaligned_shift_index); 114 rgb2 = vec_perm(rgb2, rgb3, unaligned_shift_index); 115 #if RGB_PIXELSIZE == 4 116 rgb3 = vec_perm(rgb3, rgb4, unaligned_shift_index); 117 #endif 118 } 119 } else { 120 #endif /* __BIG_ENDIAN__ */ 121 if (num_cols < RGB_PIXELSIZE * 16 && (num_cols & 15)) { 122 /* Slow path */ 123 memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16)); 124 rgb0 = VEC_LD(0, tmpbuf); 125 rgb1 = VEC_LD(16, tmpbuf); 126 rgb2 = VEC_LD(32, tmpbuf); 127 #if RGB_PIXELSIZE == 4 128 rgb3 = VEC_LD(48, tmpbuf); 129 #endif 130 } else { 131 /* Fast path */ 132 rgb0 = VEC_LD(0, inptr); 133 if (num_cols > 16) 134 rgb1 = VEC_LD(16, inptr); 135 if (num_cols > 32) 136 rgb2 = VEC_LD(32, inptr); 137 #if RGB_PIXELSIZE == 4 138 if (num_cols > 48) 139 rgb3 = VEC_LD(48, inptr); 140 #endif 141 } 142 #if __BIG_ENDIAN__ 143 } 144 #endif 145 146 #if RGB_PIXELSIZE == 3 147 /* rgb0 = R0 G0 B0 R1 G1 B1 R2 G2 B2 R3 G3 B3 R4 G4 B4 R5 148 * rgb1 = G5 B5 R6 G6 B6 R7 G7 B7 R8 G8 B8 R9 G9 B9 Ra Ga 149 * rgb2 = Ba Rb Gb Bb Rc Gc Bc Rd Gd Bd Re Ge Be Rf Gf Bf 150 * 151 * rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3 152 * rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7 153 * rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb 154 * rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf 155 */ 156 rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX0); 157 rgbg1 = vec_perm(rgb0, rgb1, (__vector unsigned char)RGBG_INDEX1); 158 rgbg2 = vec_perm(rgb1, rgb2, (__vector unsigned char)RGBG_INDEX2); 159 rgbg3 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX3); 160 #else 161 /* rgb0 = R0 G0 B0 X0 R1 G1 B1 X1 R2 G2 B2 X2 R3 G3 B3 X3 162 * rgb1 = R4 G4 B4 X4 R5 G5 B5 X5 R6 G6 B6 X6 R7 G7 B7 X7 163 * rgb2 = R8 G8 B8 X8 R9 G9 B9 X9 Ra Ga Ba Xa Rb Gb Bb Xb 164 * rgb3 = Rc Gc Bc Xc Rd Gd Bd Xd Re Ge Be Xe Rf Gf Bf Xf 165 * 166 * rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3 167 * rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7 168 * rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb 169 * rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf 170 */ 171 rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX); 172 rgbg1 = vec_perm(rgb1, rgb1, (__vector unsigned char)RGBG_INDEX); 173 rgbg2 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX); 174 rgbg3 = vec_perm(rgb3, rgb3, (__vector unsigned char)RGBG_INDEX); 175 #endif 176 177 /* rg0 = R0 G0 R1 G1 R2 G2 R3 G3 178 * bg0 = B0 G0 B1 G1 B2 G2 B3 G3 179 * ... 180 * 181 * NOTE: We have to use vec_merge*() here because vec_unpack*() doesn't 182 * support unsigned vectors. 183 */ 184 rg0 = (__vector signed short)VEC_UNPACKHU(rgbg0); 185 bg0 = (__vector signed short)VEC_UNPACKLU(rgbg0); 186 rg1 = (__vector signed short)VEC_UNPACKHU(rgbg1); 187 bg1 = (__vector signed short)VEC_UNPACKLU(rgbg1); 188 rg2 = (__vector signed short)VEC_UNPACKHU(rgbg2); 189 bg2 = (__vector signed short)VEC_UNPACKLU(rgbg2); 190 rg3 = (__vector signed short)VEC_UNPACKHU(rgbg3); 191 bg3 = (__vector signed short)VEC_UNPACKLU(rgbg3); 192 193 /* (Original) 194 * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B 195 * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE 196 * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE 197 * 198 * (This implementation) 199 * Y = 0.29900 * R + 0.33700 * G + 0.11400 * B + 0.25000 * G 200 * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE 201 * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE 202 */ 203 204 /* Calculate Y values */ 205 206 y0 = vec_msums(rg0, pw_f0299_f0337, pd_onehalf); 207 y1 = vec_msums(rg1, pw_f0299_f0337, pd_onehalf); 208 y2 = vec_msums(rg2, pw_f0299_f0337, pd_onehalf); 209 y3 = vec_msums(rg3, pw_f0299_f0337, pd_onehalf); 210 y0 = vec_msums(bg0, pw_f0114_f0250, y0); 211 y1 = vec_msums(bg1, pw_f0114_f0250, y1); 212 y2 = vec_msums(bg2, pw_f0114_f0250, y2); 213 y3 = vec_msums(bg3, pw_f0114_f0250, y3); 214 /* Clever way to avoid 4 shifts + 2 packs. This packs the high word from 215 * each dword into a new 16-bit vector, which is the equivalent of 216 * descaling the 32-bit results (right-shifting by 16 bits) and then 217 * packing them. 218 */ 219 yl = vec_perm((__vector unsigned short)y0, (__vector unsigned short)y1, 220 shift_pack_index); 221 yh = vec_perm((__vector unsigned short)y2, (__vector unsigned short)y3, 222 shift_pack_index); 223 y = vec_pack(yl, yh); 224 vec_st(y, 0, outptr0); 225 226 /* Calculate Cb values */ 227 cb0 = vec_msums(rg0, pw_mf016_mf033, pd_onehalfm1_cj); 228 cb1 = vec_msums(rg1, pw_mf016_mf033, pd_onehalfm1_cj); 229 cb2 = vec_msums(rg2, pw_mf016_mf033, pd_onehalfm1_cj); 230 cb3 = vec_msums(rg3, pw_mf016_mf033, pd_onehalfm1_cj); 231 cb0 = (__vector int)vec_msum((__vector unsigned short)bg0, pw_f050_f000, 232 (__vector unsigned int)cb0); 233 cb1 = (__vector int)vec_msum((__vector unsigned short)bg1, pw_f050_f000, 234 (__vector unsigned int)cb1); 235 cb2 = (__vector int)vec_msum((__vector unsigned short)bg2, pw_f050_f000, 236 (__vector unsigned int)cb2); 237 cb3 = (__vector int)vec_msum((__vector unsigned short)bg3, pw_f050_f000, 238 (__vector unsigned int)cb3); 239 cbl = vec_perm((__vector unsigned short)cb0, 240 (__vector unsigned short)cb1, shift_pack_index); 241 cbh = vec_perm((__vector unsigned short)cb2, 242 (__vector unsigned short)cb3, shift_pack_index); 243 cb = vec_pack(cbl, cbh); 244 vec_st(cb, 0, outptr1); 245 246 /* Calculate Cr values */ 247 cr0 = vec_msums(bg0, pw_mf008_mf041, pd_onehalfm1_cj); 248 cr1 = vec_msums(bg1, pw_mf008_mf041, pd_onehalfm1_cj); 249 cr2 = vec_msums(bg2, pw_mf008_mf041, pd_onehalfm1_cj); 250 cr3 = vec_msums(bg3, pw_mf008_mf041, pd_onehalfm1_cj); 251 cr0 = (__vector int)vec_msum((__vector unsigned short)rg0, pw_f050_f000, 252 (__vector unsigned int)cr0); 253 cr1 = (__vector int)vec_msum((__vector unsigned short)rg1, pw_f050_f000, 254 (__vector unsigned int)cr1); 255 cr2 = (__vector int)vec_msum((__vector unsigned short)rg2, pw_f050_f000, 256 (__vector unsigned int)cr2); 257 cr3 = (__vector int)vec_msum((__vector unsigned short)rg3, pw_f050_f000, 258 (__vector unsigned int)cr3); 259 crl = vec_perm((__vector unsigned short)cr0, 260 (__vector unsigned short)cr1, shift_pack_index); 261 crh = vec_perm((__vector unsigned short)cr2, 262 (__vector unsigned short)cr3, shift_pack_index); 263 cr = vec_pack(crl, crh); 264 vec_st(cr, 0, outptr2); 265 } 266 } 267 } 268
