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 = {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