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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 // Utilities for processing transparent channel.
11 //
12 // Author(s): Branimir Vasic (branimir.vasic@imgtec.com)
13 //            Djordje Pesut  (djordje.pesut@imgtec.com)
14 
15 #include "./dsp.h"
16 
17 #if defined(WEBP_USE_MIPS_DSP_R2)
18 
DispatchAlpha(const uint8_t * alpha,int alpha_stride,int width,int height,uint8_t * dst,int dst_stride)19 static int DispatchAlpha(const uint8_t* alpha, int alpha_stride,
20                          int width, int height,
21                          uint8_t* dst, int dst_stride) {
22   uint32_t alpha_mask = 0xffffffff;
23   int i, j, temp0;
24 
25   for (j = 0; j < height; ++j) {
26     uint8_t* pdst = dst;
27     const uint8_t* palpha = alpha;
28     for (i = 0; i < (width >> 2); ++i) {
29       int temp1, temp2, temp3;
30 
31       __asm__ volatile (
32         "ulw    %[temp0],      0(%[palpha])                \n\t"
33         "addiu  %[palpha],     %[palpha],     4            \n\t"
34         "addiu  %[pdst],       %[pdst],       16           \n\t"
35         "srl    %[temp1],      %[temp0],      8            \n\t"
36         "srl    %[temp2],      %[temp0],      16           \n\t"
37         "srl    %[temp3],      %[temp0],      24           \n\t"
38         "and    %[alpha_mask], %[alpha_mask], %[temp0]     \n\t"
39         "sb     %[temp0],      -16(%[pdst])                \n\t"
40         "sb     %[temp1],      -12(%[pdst])                \n\t"
41         "sb     %[temp2],      -8(%[pdst])                 \n\t"
42         "sb     %[temp3],      -4(%[pdst])                 \n\t"
43         : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp2]"=&r"(temp2),
44           [temp3]"=&r"(temp3), [palpha]"+r"(palpha), [pdst]"+r"(pdst),
45           [alpha_mask]"+r"(alpha_mask)
46         :
47         : "memory"
48       );
49     }
50 
51     for (i = 0; i < (width & 3); ++i) {
52       __asm__ volatile (
53         "lbu    %[temp0],      0(%[palpha])                \n\t"
54         "addiu  %[palpha],     %[palpha],     1            \n\t"
55         "sb     %[temp0],      0(%[pdst])                  \n\t"
56         "and    %[alpha_mask], %[alpha_mask], %[temp0]     \n\t"
57         "addiu  %[pdst],       %[pdst],       4            \n\t"
58         : [temp0]"=&r"(temp0), [palpha]"+r"(palpha), [pdst]"+r"(pdst),
59           [alpha_mask]"+r"(alpha_mask)
60         :
61         : "memory"
62       );
63     }
64     alpha += alpha_stride;
65     dst += dst_stride;
66   }
67 
68   __asm__ volatile (
69     "ext    %[temp0],      %[alpha_mask], 0, 16            \n\t"
70     "srl    %[alpha_mask], %[alpha_mask], 16               \n\t"
71     "and    %[alpha_mask], %[alpha_mask], %[temp0]         \n\t"
72     "ext    %[temp0],      %[alpha_mask], 0, 8             \n\t"
73     "srl    %[alpha_mask], %[alpha_mask], 8                \n\t"
74     "and    %[alpha_mask], %[alpha_mask], %[temp0]         \n\t"
75     : [temp0]"=&r"(temp0), [alpha_mask]"+r"(alpha_mask)
76     :
77   );
78 
79   return (alpha_mask != 0xff);
80 }
81 
MultARGBRow(uint32_t * const ptr,int width,int inverse)82 static void MultARGBRow(uint32_t* const ptr, int width, int inverse) {
83   int x;
84   const uint32_t c_00ffffff = 0x00ffffffu;
85   const uint32_t c_ff000000 = 0xff000000u;
86   const uint32_t c_8000000  = 0x00800000u;
87   const uint32_t c_8000080  = 0x00800080u;
88   for (x = 0; x < width; ++x) {
89     const uint32_t argb = ptr[x];
90     if (argb < 0xff000000u) {      // alpha < 255
91       if (argb <= 0x00ffffffu) {   // alpha == 0
92         ptr[x] = 0;
93       } else {
94         int temp0, temp1, temp2, temp3, alpha;
95         __asm__ volatile (
96           "srl          %[alpha],   %[argb],       24                \n\t"
97           "replv.qb     %[temp0],   %[alpha]                         \n\t"
98           "and          %[temp0],   %[temp0],      %[c_00ffffff]     \n\t"
99           "beqz         %[inverse], 0f                               \n\t"
100           "divu         $zero,      %[c_ff000000], %[alpha]          \n\t"
101           "mflo         %[temp0]                                     \n\t"
102         "0:                                                          \n\t"
103           "andi         %[temp1],   %[argb],       0xff              \n\t"
104           "ext          %[temp2],   %[argb],       8,             8  \n\t"
105           "ext          %[temp3],   %[argb],       16,            8  \n\t"
106           "mul          %[temp1],   %[temp1],      %[temp0]          \n\t"
107           "mul          %[temp2],   %[temp2],      %[temp0]          \n\t"
108           "mul          %[temp3],   %[temp3],      %[temp0]          \n\t"
109           "precrq.ph.w  %[temp1],   %[temp2],      %[temp1]          \n\t"
110           "addu         %[temp3],   %[temp3],      %[c_8000000]      \n\t"
111           "addu         %[temp1],   %[temp1],      %[c_8000080]      \n\t"
112           "precrq.ph.w  %[temp3],   %[argb],       %[temp3]          \n\t"
113           "precrq.qb.ph %[temp1],   %[temp3],      %[temp1]          \n\t"
114           : [temp0]"=&r"(temp0), [temp1]"=&r"(temp1), [temp2]"=&r"(temp2),
115             [temp3]"=&r"(temp3), [alpha]"=&r"(alpha)
116           : [inverse]"r"(inverse), [c_00ffffff]"r"(c_00ffffff),
117             [c_8000000]"r"(c_8000000), [c_8000080]"r"(c_8000080),
118             [c_ff000000]"r"(c_ff000000), [argb]"r"(argb)
119           : "memory", "hi", "lo"
120         );
121         ptr[x] = temp1;
122       }
123     }
124   }
125 }
126 
127 //------------------------------------------------------------------------------
128 // Entry point
129 
130 extern void WebPInitAlphaProcessingMIPSdspR2(void);
131 
WebPInitAlphaProcessingMIPSdspR2(void)132 WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingMIPSdspR2(void) {
133   WebPDispatchAlpha = DispatchAlpha;
134   WebPMultARGBRow = MultARGBRow;
135 }
136 
137 #else  // !WEBP_USE_MIPS_DSP_R2
138 
139 WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingMIPSdspR2)
140 
141 #endif  // WEBP_USE_MIPS_DSP_R2
142