1 // Copyright 2015 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 version of rescaling functions
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 #include <assert.h>
20 #include "./neon.h"
21 #include "../utils/rescaler.h"
22
23 #define ROUNDER (WEBP_RESCALER_ONE >> 1)
24 #define MULT_FIX_C(x, y) (((uint64_t)(x) * (y) + ROUNDER) >> WEBP_RESCALER_RFIX)
25
26 #define LOAD_32x4(SRC, DST) const uint32x4_t DST = vld1q_u32((SRC))
27 #define LOAD_32x8(SRC, DST0, DST1) \
28 LOAD_32x4(SRC + 0, DST0); \
29 LOAD_32x4(SRC + 4, DST1)
30
31 #define STORE_32x8(SRC0, SRC1, DST) do { \
32 vst1q_u32((DST) + 0, SRC0); \
33 vst1q_u32((DST) + 4, SRC1); \
34 } while (0);
35
36 #if (WEBP_RESCALER_RFIX == 32)
37 #define MAKE_HALF_CST(C) vdupq_n_s32((int32_t)((C) >> 1))
38 #define MULT_FIX(A, B) /* note: B is actualy scale>>1. See MAKE_HALF_CST */ \
39 vreinterpretq_u32_s32(vqrdmulhq_s32(vreinterpretq_s32_u32((A)), (B)))
40 #else
41 #error "MULT_FIX/WEBP_RESCALER_RFIX need some more work"
42 #endif
43
Interpolate(const rescaler_t * const frow,const rescaler_t * const irow,uint32_t A,uint32_t B)44 static uint32x4_t Interpolate(const rescaler_t* const frow,
45 const rescaler_t* const irow,
46 uint32_t A, uint32_t B) {
47 LOAD_32x4(frow, A0);
48 LOAD_32x4(irow, B0);
49 const uint64x2_t C0 = vmull_n_u32(vget_low_u32(A0), A);
50 const uint64x2_t C1 = vmull_n_u32(vget_high_u32(A0), A);
51 const uint64x2_t D0 = vmlal_n_u32(C0, vget_low_u32(B0), B);
52 const uint64x2_t D1 = vmlal_n_u32(C1, vget_high_u32(B0), B);
53 const uint32x4_t E = vcombine_u32(
54 vrshrn_n_u64(D0, WEBP_RESCALER_RFIX),
55 vrshrn_n_u64(D1, WEBP_RESCALER_RFIX));
56 return E;
57 }
58
RescalerExportRowExpand(WebPRescaler * const wrk)59 static void RescalerExportRowExpand(WebPRescaler* const wrk) {
60 int x_out;
61 uint8_t* const dst = wrk->dst;
62 rescaler_t* const irow = wrk->irow;
63 const int x_out_max = wrk->dst_width * wrk->num_channels;
64 const int max_span = x_out_max & ~7;
65 const rescaler_t* const frow = wrk->frow;
66 const uint32_t fy_scale = wrk->fy_scale;
67 const int32x4_t fy_scale_half = MAKE_HALF_CST(fy_scale);
68 assert(!WebPRescalerOutputDone(wrk));
69 assert(wrk->y_accum <= 0);
70 assert(wrk->y_expand);
71 assert(wrk->y_sub != 0);
72 if (wrk->y_accum == 0) {
73 for (x_out = 0; x_out < max_span; x_out += 8) {
74 LOAD_32x4(frow + x_out + 0, A0);
75 LOAD_32x4(frow + x_out + 4, A1);
76 const uint32x4_t B0 = MULT_FIX(A0, fy_scale_half);
77 const uint32x4_t B1 = MULT_FIX(A1, fy_scale_half);
78 const uint16x4_t C0 = vmovn_u32(B0);
79 const uint16x4_t C1 = vmovn_u32(B1);
80 const uint8x8_t D = vmovn_u16(vcombine_u16(C0, C1));
81 vst1_u8(dst + x_out, D);
82 }
83 for (; x_out < x_out_max; ++x_out) {
84 const uint32_t J = frow[x_out];
85 const int v = (int)MULT_FIX_C(J, fy_scale);
86 assert(v >= 0 && v <= 255);
87 dst[x_out] = v;
88 }
89 } else {
90 const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub);
91 const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B);
92 for (x_out = 0; x_out < max_span; x_out += 8) {
93 const uint32x4_t C0 =
94 Interpolate(frow + x_out + 0, irow + x_out + 0, A, B);
95 const uint32x4_t C1 =
96 Interpolate(frow + x_out + 4, irow + x_out + 4, A, B);
97 const uint32x4_t D0 = MULT_FIX(C0, fy_scale_half);
98 const uint32x4_t D1 = MULT_FIX(C1, fy_scale_half);
99 const uint16x4_t E0 = vmovn_u32(D0);
100 const uint16x4_t E1 = vmovn_u32(D1);
101 const uint8x8_t F = vmovn_u16(vcombine_u16(E0, E1));
102 vst1_u8(dst + x_out, F);
103 }
104 for (; x_out < x_out_max; ++x_out) {
105 const uint64_t I = (uint64_t)A * frow[x_out]
106 + (uint64_t)B * irow[x_out];
107 const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX);
108 const int v = (int)MULT_FIX_C(J, fy_scale);
109 assert(v >= 0 && v <= 255);
110 dst[x_out] = v;
111 }
112 }
113 }
114
RescalerExportRowShrink(WebPRescaler * const wrk)115 static void RescalerExportRowShrink(WebPRescaler* const wrk) {
116 int x_out;
117 uint8_t* const dst = wrk->dst;
118 rescaler_t* const irow = wrk->irow;
119 const int x_out_max = wrk->dst_width * wrk->num_channels;
120 const int max_span = x_out_max & ~7;
121 const rescaler_t* const frow = wrk->frow;
122 const uint32_t yscale = wrk->fy_scale * (-wrk->y_accum);
123 const uint32_t fxy_scale = wrk->fxy_scale;
124 const uint32x4_t zero = vdupq_n_u32(0);
125 const int32x4_t yscale_half = MAKE_HALF_CST(yscale);
126 const int32x4_t fxy_scale_half = MAKE_HALF_CST(fxy_scale);
127 assert(!WebPRescalerOutputDone(wrk));
128 assert(wrk->y_accum <= 0);
129 assert(!wrk->y_expand);
130 if (yscale) {
131 for (x_out = 0; x_out < max_span; x_out += 8) {
132 LOAD_32x8(frow + x_out, in0, in1);
133 LOAD_32x8(irow + x_out, in2, in3);
134 const uint32x4_t A0 = MULT_FIX(in0, yscale_half);
135 const uint32x4_t A1 = MULT_FIX(in1, yscale_half);
136 const uint32x4_t B0 = vqsubq_u32(in2, A0);
137 const uint32x4_t B1 = vqsubq_u32(in3, A1);
138 const uint32x4_t C0 = MULT_FIX(B0, fxy_scale_half);
139 const uint32x4_t C1 = MULT_FIX(B1, fxy_scale_half);
140 const uint16x4_t D0 = vmovn_u32(C0);
141 const uint16x4_t D1 = vmovn_u32(C1);
142 const uint8x8_t E = vmovn_u16(vcombine_u16(D0, D1));
143 vst1_u8(dst + x_out, E);
144 STORE_32x8(A0, A1, irow + x_out);
145 }
146 for (; x_out < x_out_max; ++x_out) {
147 const uint32_t frac = (uint32_t)MULT_FIX_C(frow[x_out], yscale);
148 const int v = (int)MULT_FIX_C(irow[x_out] - frac, wrk->fxy_scale);
149 assert(v >= 0 && v <= 255);
150 dst[x_out] = v;
151 irow[x_out] = frac; // new fractional start
152 }
153 } else {
154 for (x_out = 0; x_out < max_span; x_out += 8) {
155 LOAD_32x8(irow + x_out, in0, in1);
156 const uint32x4_t A0 = MULT_FIX(in0, fxy_scale_half);
157 const uint32x4_t A1 = MULT_FIX(in1, fxy_scale_half);
158 const uint16x4_t B0 = vmovn_u32(A0);
159 const uint16x4_t B1 = vmovn_u32(A1);
160 const uint8x8_t C = vmovn_u16(vcombine_u16(B0, B1));
161 vst1_u8(dst + x_out, C);
162 STORE_32x8(zero, zero, irow + x_out);
163 }
164 for (; x_out < x_out_max; ++x_out) {
165 const int v = (int)MULT_FIX_C(irow[x_out], fxy_scale);
166 assert(v >= 0 && v <= 255);
167 dst[x_out] = v;
168 irow[x_out] = 0;
169 }
170 }
171 }
172
173 //------------------------------------------------------------------------------
174
175 extern void WebPRescalerDspInitNEON(void);
176
WebPRescalerDspInitNEON(void)177 WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitNEON(void) {
178 WebPRescalerExportRowExpand = RescalerExportRowExpand;
179 WebPRescalerExportRowShrink = RescalerExportRowShrink;
180 }
181
182 #else // !WEBP_USE_NEON
183
184 WEBP_DSP_INIT_STUB(WebPRescalerDspInitNEON)
185
186 #endif // WEBP_USE_NEON
187