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
jsimd_rgb_ycc_convert_altivec(JDIMENSION img_width,JSAMPARRAY input_buf,JSAMPIMAGE output_buf,JDIMENSION output_row,int num_rows)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 =
61 { 0, 1, 4, 5, 8, 9, 12, 13, 16, 17, 20, 21, 24, 25, 28, 29 };
62 #else
63 shift_pack_index =
64 { 2, 3, 6, 7, 10, 11, 14, 15, 18, 19, 22, 23, 26, 27, 30, 31 };
65 #endif
66
67 while (--num_rows >= 0) {
68 inptr = *input_buf++;
69 outptr0 = output_buf[0][output_row];
70 outptr1 = output_buf[1][output_row];
71 outptr2 = output_buf[2][output_row];
72 output_row++;
73
74 for (num_cols = pitch; num_cols > 0;
75 num_cols -= RGB_PIXELSIZE * 16, inptr += RGB_PIXELSIZE * 16,
76 outptr0 += 16, outptr1 += 16, outptr2 += 16) {
77
78 #if __BIG_ENDIAN__
79 /* Load 16 pixels == 48 or 64 bytes */
80 offset = (size_t)inptr & 15;
81 if (offset) {
82 __vector unsigned char unaligned_shift_index;
83 int bytes = num_cols + offset;
84
85 if (bytes < (RGB_PIXELSIZE + 1) * 16 && (bytes & 15)) {
86 /* Slow path to prevent buffer overread. Since there is no way to
87 * read a partial AltiVec register, overread would occur on the last
88 * chunk of the last image row if the right edge is not on a 16-byte
89 * boundary. It could also occur on other rows if the bytes per row
90 * is low enough. Since we can't determine whether we're on the last
91 * image row, we have to assume every row is the last.
92 */
93 memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16));
94 rgb0 = vec_ld(0, tmpbuf);
95 rgb1 = vec_ld(16, tmpbuf);
96 rgb2 = vec_ld(32, tmpbuf);
97 #if RGB_PIXELSIZE == 4
98 rgb3 = vec_ld(48, tmpbuf);
99 #endif
100 } else {
101 /* Fast path */
102 rgb0 = vec_ld(0, inptr);
103 if (bytes > 16)
104 rgb1 = vec_ld(16, inptr);
105 if (bytes > 32)
106 rgb2 = vec_ld(32, inptr);
107 if (bytes > 48)
108 rgb3 = vec_ld(48, inptr);
109 #if RGB_PIXELSIZE == 4
110 if (bytes > 64)
111 rgb4 = vec_ld(64, inptr);
112 #endif
113 unaligned_shift_index = vec_lvsl(0, inptr);
114 rgb0 = vec_perm(rgb0, rgb1, unaligned_shift_index);
115 rgb1 = vec_perm(rgb1, rgb2, unaligned_shift_index);
116 rgb2 = vec_perm(rgb2, rgb3, unaligned_shift_index);
117 #if RGB_PIXELSIZE == 4
118 rgb3 = vec_perm(rgb3, rgb4, unaligned_shift_index);
119 #endif
120 }
121 } else {
122 #endif /* __BIG_ENDIAN__ */
123 if (num_cols < RGB_PIXELSIZE * 16 && (num_cols & 15)) {
124 /* Slow path */
125 memcpy(tmpbuf, inptr, min(num_cols, RGB_PIXELSIZE * 16));
126 rgb0 = VEC_LD(0, tmpbuf);
127 rgb1 = VEC_LD(16, tmpbuf);
128 rgb2 = VEC_LD(32, tmpbuf);
129 #if RGB_PIXELSIZE == 4
130 rgb3 = VEC_LD(48, tmpbuf);
131 #endif
132 } else {
133 /* Fast path */
134 rgb0 = VEC_LD(0, inptr);
135 if (num_cols > 16)
136 rgb1 = VEC_LD(16, inptr);
137 if (num_cols > 32)
138 rgb2 = VEC_LD(32, inptr);
139 #if RGB_PIXELSIZE == 4
140 if (num_cols > 48)
141 rgb3 = VEC_LD(48, inptr);
142 #endif
143 }
144 #if __BIG_ENDIAN__
145 }
146 #endif
147
148 #if RGB_PIXELSIZE == 3
149 /* rgb0 = R0 G0 B0 R1 G1 B1 R2 G2 B2 R3 G3 B3 R4 G4 B4 R5
150 * rgb1 = G5 B5 R6 G6 B6 R7 G7 B7 R8 G8 B8 R9 G9 B9 Ra Ga
151 * rgb2 = Ba Rb Gb Bb Rc Gc Bc Rd Gd Bd Re Ge Be Rf Gf Bf
152 *
153 * rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3
154 * rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7
155 * rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb
156 * rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf
157 */
158 rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX0);
159 rgbg1 = vec_perm(rgb0, rgb1, (__vector unsigned char)RGBG_INDEX1);
160 rgbg2 = vec_perm(rgb1, rgb2, (__vector unsigned char)RGBG_INDEX2);
161 rgbg3 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX3);
162 #else
163 /* rgb0 = R0 G0 B0 X0 R1 G1 B1 X1 R2 G2 B2 X2 R3 G3 B3 X3
164 * rgb1 = R4 G4 B4 X4 R5 G5 B5 X5 R6 G6 B6 X6 R7 G7 B7 X7
165 * rgb2 = R8 G8 B8 X8 R9 G9 B9 X9 Ra Ga Ba Xa Rb Gb Bb Xb
166 * rgb3 = Rc Gc Bc Xc Rd Gd Bd Xd Re Ge Be Xe Rf Gf Bf Xf
167 *
168 * rgbg0 = R0 G0 R1 G1 R2 G2 R3 G3 B0 G0 B1 G1 B2 G2 B3 G3
169 * rgbg1 = R4 G4 R5 G5 R6 G6 R7 G7 B4 G4 B5 G5 B6 G6 B7 G7
170 * rgbg2 = R8 G8 R9 G9 Ra Ga Rb Gb B8 G8 B9 G9 Ba Ga Bb Gb
171 * rgbg3 = Rc Gc Rd Gd Re Ge Rf Gf Bc Gc Bd Gd Be Ge Bf Gf
172 */
173 rgbg0 = vec_perm(rgb0, rgb0, (__vector unsigned char)RGBG_INDEX);
174 rgbg1 = vec_perm(rgb1, rgb1, (__vector unsigned char)RGBG_INDEX);
175 rgbg2 = vec_perm(rgb2, rgb2, (__vector unsigned char)RGBG_INDEX);
176 rgbg3 = vec_perm(rgb3, rgb3, (__vector unsigned char)RGBG_INDEX);
177 #endif
178
179 /* rg0 = R0 G0 R1 G1 R2 G2 R3 G3
180 * bg0 = B0 G0 B1 G1 B2 G2 B3 G3
181 * ...
182 *
183 * NOTE: We have to use vec_merge*() here because vec_unpack*() doesn't
184 * support unsigned vectors.
185 */
186 rg0 = (__vector signed short)VEC_UNPACKHU(rgbg0);
187 bg0 = (__vector signed short)VEC_UNPACKLU(rgbg0);
188 rg1 = (__vector signed short)VEC_UNPACKHU(rgbg1);
189 bg1 = (__vector signed short)VEC_UNPACKLU(rgbg1);
190 rg2 = (__vector signed short)VEC_UNPACKHU(rgbg2);
191 bg2 = (__vector signed short)VEC_UNPACKLU(rgbg2);
192 rg3 = (__vector signed short)VEC_UNPACKHU(rgbg3);
193 bg3 = (__vector signed short)VEC_UNPACKLU(rgbg3);
194
195 /* (Original)
196 * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
197 * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
198 * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
199 *
200 * (This implementation)
201 * Y = 0.29900 * R + 0.33700 * G + 0.11400 * B + 0.25000 * G
202 * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
203 * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
204 */
205
206 /* Calculate Y values */
207
208 y0 = vec_msums(rg0, pw_f0299_f0337, pd_onehalf);
209 y1 = vec_msums(rg1, pw_f0299_f0337, pd_onehalf);
210 y2 = vec_msums(rg2, pw_f0299_f0337, pd_onehalf);
211 y3 = vec_msums(rg3, pw_f0299_f0337, pd_onehalf);
212 y0 = vec_msums(bg0, pw_f0114_f0250, y0);
213 y1 = vec_msums(bg1, pw_f0114_f0250, y1);
214 y2 = vec_msums(bg2, pw_f0114_f0250, y2);
215 y3 = vec_msums(bg3, pw_f0114_f0250, y3);
216 /* Clever way to avoid 4 shifts + 2 packs. This packs the high word from
217 * each dword into a new 16-bit vector, which is the equivalent of
218 * descaling the 32-bit results (right-shifting by 16 bits) and then
219 * packing them.
220 */
221 yl = vec_perm((__vector unsigned short)y0, (__vector unsigned short)y1,
222 shift_pack_index);
223 yh = vec_perm((__vector unsigned short)y2, (__vector unsigned short)y3,
224 shift_pack_index);
225 y = vec_pack(yl, yh);
226 vec_st(y, 0, outptr0);
227
228 /* Calculate Cb values */
229 cb0 = vec_msums(rg0, pw_mf016_mf033, pd_onehalfm1_cj);
230 cb1 = vec_msums(rg1, pw_mf016_mf033, pd_onehalfm1_cj);
231 cb2 = vec_msums(rg2, pw_mf016_mf033, pd_onehalfm1_cj);
232 cb3 = vec_msums(rg3, pw_mf016_mf033, pd_onehalfm1_cj);
233 cb0 = (__vector int)vec_msum((__vector unsigned short)bg0, pw_f050_f000,
234 (__vector unsigned int)cb0);
235 cb1 = (__vector int)vec_msum((__vector unsigned short)bg1, pw_f050_f000,
236 (__vector unsigned int)cb1);
237 cb2 = (__vector int)vec_msum((__vector unsigned short)bg2, pw_f050_f000,
238 (__vector unsigned int)cb2);
239 cb3 = (__vector int)vec_msum((__vector unsigned short)bg3, pw_f050_f000,
240 (__vector unsigned int)cb3);
241 cbl = vec_perm((__vector unsigned short)cb0,
242 (__vector unsigned short)cb1, shift_pack_index);
243 cbh = vec_perm((__vector unsigned short)cb2,
244 (__vector unsigned short)cb3, shift_pack_index);
245 cb = vec_pack(cbl, cbh);
246 vec_st(cb, 0, outptr1);
247
248 /* Calculate Cr values */
249 cr0 = vec_msums(bg0, pw_mf008_mf041, pd_onehalfm1_cj);
250 cr1 = vec_msums(bg1, pw_mf008_mf041, pd_onehalfm1_cj);
251 cr2 = vec_msums(bg2, pw_mf008_mf041, pd_onehalfm1_cj);
252 cr3 = vec_msums(bg3, pw_mf008_mf041, pd_onehalfm1_cj);
253 cr0 = (__vector int)vec_msum((__vector unsigned short)rg0, pw_f050_f000,
254 (__vector unsigned int)cr0);
255 cr1 = (__vector int)vec_msum((__vector unsigned short)rg1, pw_f050_f000,
256 (__vector unsigned int)cr1);
257 cr2 = (__vector int)vec_msum((__vector unsigned short)rg2, pw_f050_f000,
258 (__vector unsigned int)cr2);
259 cr3 = (__vector int)vec_msum((__vector unsigned short)rg3, pw_f050_f000,
260 (__vector unsigned int)cr3);
261 crl = vec_perm((__vector unsigned short)cr0,
262 (__vector unsigned short)cr1, shift_pack_index);
263 crh = vec_perm((__vector unsigned short)cr2,
264 (__vector unsigned short)cr3, shift_pack_index);
265 cr = vec_pack(crl, crh);
266 vec_st(cr, 0, outptr2);
267 }
268 }
269 }
270