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1 // Copyright 2014 Google Inc. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the COPYING file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS. All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 // -----------------------------------------------------------------------------
9 //
10 // NEON variant of methods for lossless decoder
11 //
12 // Author: Skal (pascal.massimino@gmail.com)
13 
14 #include "./dsp.h"
15 
16 #if defined(WEBP_USE_NEON)
17 
18 #include <arm_neon.h>
19 
20 #include "./lossless.h"
21 #include "./neon.h"
22 
23 //------------------------------------------------------------------------------
24 // Colorspace conversion functions
25 
26 #if !defined(WORK_AROUND_GCC)
27 // gcc 4.6.0 had some trouble (NDK-r9) with this code. We only use it for
28 // gcc-4.8.x at least.
ConvertBGRAToRGBA(const uint32_t * src,int num_pixels,uint8_t * dst)29 static void ConvertBGRAToRGBA(const uint32_t* src,
30                               int num_pixels, uint8_t* dst) {
31   const uint32_t* const end = src + (num_pixels & ~15);
32   for (; src < end; src += 16) {
33     uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
34     // swap B and R. (VSWP d0,d2 has no intrinsics equivalent!)
35     const uint8x16_t tmp = pixel.val[0];
36     pixel.val[0] = pixel.val[2];
37     pixel.val[2] = tmp;
38     vst4q_u8(dst, pixel);
39     dst += 64;
40   }
41   VP8LConvertBGRAToRGBA_C(src, num_pixels & 15, dst);  // left-overs
42 }
43 
ConvertBGRAToBGR(const uint32_t * src,int num_pixels,uint8_t * dst)44 static void ConvertBGRAToBGR(const uint32_t* src,
45                              int num_pixels, uint8_t* dst) {
46   const uint32_t* const end = src + (num_pixels & ~15);
47   for (; src < end; src += 16) {
48     const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
49     const uint8x16x3_t tmp = { { pixel.val[0], pixel.val[1], pixel.val[2] } };
50     vst3q_u8(dst, tmp);
51     dst += 48;
52   }
53   VP8LConvertBGRAToBGR_C(src, num_pixels & 15, dst);  // left-overs
54 }
55 
ConvertBGRAToRGB(const uint32_t * src,int num_pixels,uint8_t * dst)56 static void ConvertBGRAToRGB(const uint32_t* src,
57                              int num_pixels, uint8_t* dst) {
58   const uint32_t* const end = src + (num_pixels & ~15);
59   for (; src < end; src += 16) {
60     const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
61     const uint8x16x3_t tmp = { { pixel.val[2], pixel.val[1], pixel.val[0] } };
62     vst3q_u8(dst, tmp);
63     dst += 48;
64   }
65   VP8LConvertBGRAToRGB_C(src, num_pixels & 15, dst);  // left-overs
66 }
67 
68 #else  // WORK_AROUND_GCC
69 
70 // gcc-4.6.0 fallback
71 
72 static const uint8_t kRGBAShuffle[8] = { 2, 1, 0, 3, 6, 5, 4, 7 };
73 
ConvertBGRAToRGBA(const uint32_t * src,int num_pixels,uint8_t * dst)74 static void ConvertBGRAToRGBA(const uint32_t* src,
75                               int num_pixels, uint8_t* dst) {
76   const uint32_t* const end = src + (num_pixels & ~1);
77   const uint8x8_t shuffle = vld1_u8(kRGBAShuffle);
78   for (; src < end; src += 2) {
79     const uint8x8_t pixels = vld1_u8((uint8_t*)src);
80     vst1_u8(dst, vtbl1_u8(pixels, shuffle));
81     dst += 8;
82   }
83   VP8LConvertBGRAToRGBA_C(src, num_pixels & 1, dst);  // left-overs
84 }
85 
86 static const uint8_t kBGRShuffle[3][8] = {
87   {  0,  1,  2,  4,  5,  6,  8,  9 },
88   { 10, 12, 13, 14, 16, 17, 18, 20 },
89   { 21, 22, 24, 25, 26, 28, 29, 30 }
90 };
91 
ConvertBGRAToBGR(const uint32_t * src,int num_pixels,uint8_t * dst)92 static void ConvertBGRAToBGR(const uint32_t* src,
93                              int num_pixels, uint8_t* dst) {
94   const uint32_t* const end = src + (num_pixels & ~7);
95   const uint8x8_t shuffle0 = vld1_u8(kBGRShuffle[0]);
96   const uint8x8_t shuffle1 = vld1_u8(kBGRShuffle[1]);
97   const uint8x8_t shuffle2 = vld1_u8(kBGRShuffle[2]);
98   for (; src < end; src += 8) {
99     uint8x8x4_t pixels;
100     INIT_VECTOR4(pixels,
101                  vld1_u8((const uint8_t*)(src + 0)),
102                  vld1_u8((const uint8_t*)(src + 2)),
103                  vld1_u8((const uint8_t*)(src + 4)),
104                  vld1_u8((const uint8_t*)(src + 6)));
105     vst1_u8(dst +  0, vtbl4_u8(pixels, shuffle0));
106     vst1_u8(dst +  8, vtbl4_u8(pixels, shuffle1));
107     vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
108     dst += 8 * 3;
109   }
110   VP8LConvertBGRAToBGR_C(src, num_pixels & 7, dst);  // left-overs
111 }
112 
113 static const uint8_t kRGBShuffle[3][8] = {
114   {  2,  1,  0,  6,  5,  4, 10,  9 },
115   {  8, 14, 13, 12, 18, 17, 16, 22 },
116   { 21, 20, 26, 25, 24, 30, 29, 28 }
117 };
118 
ConvertBGRAToRGB(const uint32_t * src,int num_pixels,uint8_t * dst)119 static void ConvertBGRAToRGB(const uint32_t* src,
120                              int num_pixels, uint8_t* dst) {
121   const uint32_t* const end = src + (num_pixels & ~7);
122   const uint8x8_t shuffle0 = vld1_u8(kRGBShuffle[0]);
123   const uint8x8_t shuffle1 = vld1_u8(kRGBShuffle[1]);
124   const uint8x8_t shuffle2 = vld1_u8(kRGBShuffle[2]);
125   for (; src < end; src += 8) {
126     uint8x8x4_t pixels;
127     INIT_VECTOR4(pixels,
128                  vld1_u8((const uint8_t*)(src + 0)),
129                  vld1_u8((const uint8_t*)(src + 2)),
130                  vld1_u8((const uint8_t*)(src + 4)),
131                  vld1_u8((const uint8_t*)(src + 6)));
132     vst1_u8(dst +  0, vtbl4_u8(pixels, shuffle0));
133     vst1_u8(dst +  8, vtbl4_u8(pixels, shuffle1));
134     vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
135     dst += 8 * 3;
136   }
137   VP8LConvertBGRAToRGB_C(src, num_pixels & 7, dst);  // left-overs
138 }
139 
140 #endif   // !WORK_AROUND_GCC
141 
142 //------------------------------------------------------------------------------
143 // Subtract-Green Transform
144 
145 // vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use
146 // non-standard versions there.
147 #if defined(__APPLE__) && defined(__aarch64__) && \
148     defined(__apple_build_version__) && (__apple_build_version__< 6020037)
149 #define USE_VTBLQ
150 #endif
151 
152 #ifdef USE_VTBLQ
153 // 255 = byte will be zeroed
154 static const uint8_t kGreenShuffle[16] = {
155   1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13, 255
156 };
157 
DoGreenShuffle(const uint8x16_t argb,const uint8x16_t shuffle)158 static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
159                                              const uint8x16_t shuffle) {
160   return vcombine_u8(vtbl1q_u8(argb, vget_low_u8(shuffle)),
161                      vtbl1q_u8(argb, vget_high_u8(shuffle)));
162 }
163 #else  // !USE_VTBLQ
164 // 255 = byte will be zeroed
165 static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255  };
166 
DoGreenShuffle(const uint8x16_t argb,const uint8x8_t shuffle)167 static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
168                                              const uint8x8_t shuffle) {
169   return vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle),
170                      vtbl1_u8(vget_high_u8(argb), shuffle));
171 }
172 #endif  // USE_VTBLQ
173 
AddGreenToBlueAndRed(uint32_t * argb_data,int num_pixels)174 static void AddGreenToBlueAndRed(uint32_t* argb_data, int num_pixels) {
175   const uint32_t* const end = argb_data + (num_pixels & ~3);
176 #ifdef USE_VTBLQ
177   const uint8x16_t shuffle = vld1q_u8(kGreenShuffle);
178 #else
179   const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
180 #endif
181   for (; argb_data < end; argb_data += 4) {
182     const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data);
183     const uint8x16_t greens = DoGreenShuffle(argb, shuffle);
184     vst1q_u8((uint8_t*)argb_data, vaddq_u8(argb, greens));
185   }
186   // fallthrough and finish off with plain-C
187   VP8LAddGreenToBlueAndRed_C(argb_data, num_pixels & 3);
188 }
189 
190 //------------------------------------------------------------------------------
191 // Color Transform
192 
TransformColorInverse(const VP8LMultipliers * const m,uint32_t * argb_data,int num_pixels)193 static void TransformColorInverse(const VP8LMultipliers* const m,
194                                   uint32_t* argb_data, int num_pixels) {
195   // sign-extended multiplying constants, pre-shifted by 6.
196 #define CST(X)  (((int16_t)(m->X << 8)) >> 6)
197   const int16_t rb[8] = {
198     CST(green_to_blue_), CST(green_to_red_),
199     CST(green_to_blue_), CST(green_to_red_),
200     CST(green_to_blue_), CST(green_to_red_),
201     CST(green_to_blue_), CST(green_to_red_)
202   };
203   const int16x8_t mults_rb = vld1q_s16(rb);
204   const int16_t b2[8] = {
205     0, CST(red_to_blue_), 0, CST(red_to_blue_),
206     0, CST(red_to_blue_), 0, CST(red_to_blue_),
207   };
208   const int16x8_t mults_b2 = vld1q_s16(b2);
209 #undef CST
210 #ifdef USE_VTBLQ
211   static const uint8_t kg0g0[16] = {
212     255, 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13
213   };
214   const uint8x16_t shuffle = vld1q_u8(kg0g0);
215 #else
216   static const uint8_t k0g0g[8] = { 255, 1, 255, 1, 255, 5, 255, 5 };
217   const uint8x8_t shuffle = vld1_u8(k0g0g);
218 #endif
219   const uint32x4_t mask_ag = vdupq_n_u32(0xff00ff00u);
220   int i;
221   for (i = 0; i + 4 <= num_pixels; i += 4) {
222     const uint8x16_t in = vld1q_u8((uint8_t*)(argb_data + i));
223     const uint32x4_t a0g0 = vandq_u32(vreinterpretq_u32_u8(in), mask_ag);
224     // 0 g 0 g
225     const uint8x16_t greens = DoGreenShuffle(in, shuffle);
226     // x dr  x db1
227     const int16x8_t A = vqdmulhq_s16(vreinterpretq_s16_u8(greens), mults_rb);
228     // x r'  x   b'
229     const int8x16_t B = vaddq_s8(vreinterpretq_s8_u8(in),
230                                  vreinterpretq_s8_s16(A));
231     // r' 0   b' 0
232     const int16x8_t C = vshlq_n_s16(vreinterpretq_s16_s8(B), 8);
233     // x db2  0  0
234     const int16x8_t D = vqdmulhq_s16(C, mults_b2);
235     // 0  x db2  0
236     const uint32x4_t E = vshrq_n_u32(vreinterpretq_u32_s16(D), 8);
237     // r' x  b'' 0
238     const int8x16_t F = vaddq_s8(vreinterpretq_s8_u32(E),
239                                  vreinterpretq_s8_s16(C));
240     // 0  r'  0  b''
241     const uint16x8_t G = vshrq_n_u16(vreinterpretq_u16_s8(F), 8);
242     const uint32x4_t out = vorrq_u32(vreinterpretq_u32_u16(G), a0g0);
243     vst1q_u32(argb_data + i, out);
244   }
245   // Fall-back to C-version for left-overs.
246   VP8LTransformColorInverse_C(m, argb_data + i, num_pixels - i);
247 }
248 
249 #undef USE_VTBLQ
250 
251 //------------------------------------------------------------------------------
252 // Entry point
253 
254 extern void VP8LDspInitNEON(void);
255 
VP8LDspInitNEON(void)256 WEBP_TSAN_IGNORE_FUNCTION void VP8LDspInitNEON(void) {
257   VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA;
258   VP8LConvertBGRAToBGR = ConvertBGRAToBGR;
259   VP8LConvertBGRAToRGB = ConvertBGRAToRGB;
260 
261   VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
262   VP8LTransformColorInverse = TransformColorInverse;
263 }
264 
265 #else  // !WEBP_USE_NEON
266 
267 WEBP_DSP_INIT_STUB(VP8LDspInitNEON)
268 
269 #endif  // WEBP_USE_NEON
270