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 "src/dsp/dsp.h"
15
16#if defined(WEBP_USE_NEON) && !defined(WEBP_REDUCE_SIZE)
17
18#include <arm_neon.h>
19#include <assert.h>
20#include "src/dsp/neon.h"
21#include "src/utils/rescaler_utils.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#define MULT_FIX_FLOOR_C(x, y) (((uint64_t)(x) * (y)) >> WEBP_RESCALER_RFIX)
26
27#define LOAD_32x4(SRC, DST) const uint32x4_t DST = vld1q_u32((SRC))
28#define LOAD_32x8(SRC, DST0, DST1) \
29 LOAD_32x4(SRC + 0, DST0); \
30 LOAD_32x4(SRC + 4, DST1)
31
32#define STORE_32x8(SRC0, SRC1, DST) do { \
33 vst1q_u32((DST) + 0, SRC0); \
34 vst1q_u32((DST) + 4, SRC1); \
35} while (0);
36
37#if (WEBP_RESCALER_RFIX == 32)
38#define MAKE_HALF_CST(C) vdupq_n_s32((int32_t)((C) >> 1))
39// note: B is actualy scale>>1. See MAKE_HALF_CST
40#define MULT_FIX(A, B) \
41 vreinterpretq_u32_s32(vqrdmulhq_s32(vreinterpretq_s32_u32((A)), (B)))
42#define MULT_FIX_FLOOR(A, B) \
43 vreinterpretq_u32_s32(vqdmulhq_s32(vreinterpretq_s32_u32((A)), (B)))
44#else
45#error "MULT_FIX/WEBP_RESCALER_RFIX need some more work"
46#endif
47
48static uint32x4_t Interpolate_NEON(const rescaler_t* const frow,
49 const rescaler_t* const irow,
50 uint32_t A, uint32_t B) {
51 LOAD_32x4(frow, A0);
52 LOAD_32x4(irow, B0);
53 const uint64x2_t C0 = vmull_n_u32(vget_low_u32(A0), A);
54 const uint64x2_t C1 = vmull_n_u32(vget_high_u32(A0), A);
55 const uint64x2_t D0 = vmlal_n_u32(C0, vget_low_u32(B0), B);
56 const uint64x2_t D1 = vmlal_n_u32(C1, vget_high_u32(B0), B);
57 const uint32x4_t E = vcombine_u32(
58 vrshrn_n_u64(D0, WEBP_RESCALER_RFIX),
59 vrshrn_n_u64(D1, WEBP_RESCALER_RFIX));
60 return E;
61}
62
63static void RescalerExportRowExpand_NEON(WebPRescaler* const wrk) {
64 int x_out;
65 uint8_t* const dst = wrk->dst;
66 rescaler_t* const irow = wrk->irow;
67 const int x_out_max = wrk->dst_width * wrk->num_channels;
68 const int max_span = x_out_max & ~7;
69 const rescaler_t* const frow = wrk->frow;
70 const uint32_t fy_scale = wrk->fy_scale;
71 const int32x4_t fy_scale_half = MAKE_HALF_CST(fy_scale);
72 assert(!WebPRescalerOutputDone(wrk));
73 assert(wrk->y_accum <= 0);
74 assert(wrk->y_expand);
75 assert(wrk->y_sub != 0);
76 if (wrk->y_accum == 0) {
77 for (x_out = 0; x_out < max_span; x_out += 8) {
78 LOAD_32x4(frow + x_out + 0, A0);
79 LOAD_32x4(frow + x_out + 4, A1);
80 const uint32x4_t B0 = MULT_FIX(A0, fy_scale_half);
81 const uint32x4_t B1 = MULT_FIX(A1, fy_scale_half);
82 const uint16x4_t C0 = vmovn_u32(B0);
83 const uint16x4_t C1 = vmovn_u32(B1);
84 const uint8x8_t D = vqmovn_u16(vcombine_u16(C0, C1));
85 vst1_u8(dst + x_out, D);
86 }
87 for (; x_out < x_out_max; ++x_out) {
88 const uint32_t J = frow[x_out];
89 const int v = (int)MULT_FIX_C(J, fy_scale);
90 dst[x_out] = (v > 255) ? 255u : (uint8_t)v;
91 }
92 } else {
93 const uint32_t B = WEBP_RESCALER_FRAC(-wrk->y_accum, wrk->y_sub);
94 const uint32_t A = (uint32_t)(WEBP_RESCALER_ONE - B);
95 for (x_out = 0; x_out < max_span; x_out += 8) {
96 const uint32x4_t C0 =
97 Interpolate_NEON(frow + x_out + 0, irow + x_out + 0, A, B);
98 const uint32x4_t C1 =
99 Interpolate_NEON(frow + x_out + 4, irow + x_out + 4, A, B);
100 const uint32x4_t D0 = MULT_FIX(C0, fy_scale_half);
101 const uint32x4_t D1 = MULT_FIX(C1, fy_scale_half);
102 const uint16x4_t E0 = vmovn_u32(D0);
103 const uint16x4_t E1 = vmovn_u32(D1);
104 const uint8x8_t F = vqmovn_u16(vcombine_u16(E0, E1));
105 vst1_u8(dst + x_out, F);
106 }
107 for (; x_out < x_out_max; ++x_out) {
108 const uint64_t I = (uint64_t)A * frow[x_out]
109 + (uint64_t)B * irow[x_out];
110 const uint32_t J = (uint32_t)((I + ROUNDER) >> WEBP_RESCALER_RFIX);
111 const int v = (int)MULT_FIX_C(J, fy_scale);
112 dst[x_out] = (v > 255) ? 255u : (uint8_t)v;
113 }
114 }
115}
116
117static void RescalerExportRowShrink_NEON(WebPRescaler* const wrk) {
118 int x_out;
119 uint8_t* const dst = wrk->dst;
120 rescaler_t* const irow = wrk->irow;
121 const int x_out_max = wrk->dst_width * wrk->num_channels;
122 const int max_span = x_out_max & ~7;
123 const rescaler_t* const frow = wrk->frow;
124 const uint32_t yscale = wrk->fy_scale * (-wrk->y_accum);
125 const uint32_t fxy_scale = wrk->fxy_scale;
126 const uint32x4_t zero = vdupq_n_u32(0);
127 const int32x4_t yscale_half = MAKE_HALF_CST(yscale);
128 const int32x4_t fxy_scale_half = MAKE_HALF_CST(fxy_scale);
129 assert(!WebPRescalerOutputDone(wrk));
130 assert(wrk->y_accum <= 0);
131 assert(!wrk->y_expand);
132 if (yscale) {
133 for (x_out = 0; x_out < max_span; x_out += 8) {
134 LOAD_32x8(frow + x_out, in0, in1);
135 LOAD_32x8(irow + x_out, in2, in3);
136 const uint32x4_t A0 = MULT_FIX_FLOOR(in0, yscale_half);
137 const uint32x4_t A1 = MULT_FIX_FLOOR(in1, yscale_half);
138 const uint32x4_t B0 = vqsubq_u32(in2, A0);
139 const uint32x4_t B1 = vqsubq_u32(in3, A1);
140 const uint32x4_t C0 = MULT_FIX(B0, fxy_scale_half);
141 const uint32x4_t C1 = MULT_FIX(B1, fxy_scale_half);
142 const uint16x4_t D0 = vmovn_u32(C0);
143 const uint16x4_t D1 = vmovn_u32(C1);
144 const uint8x8_t E = vqmovn_u16(vcombine_u16(D0, D1));
145 vst1_u8(dst + x_out, E);
146 STORE_32x8(A0, A1, irow + x_out);
147 }
148 for (; x_out < x_out_max; ++x_out) {
149 const uint32_t frac = (uint32_t)MULT_FIX_FLOOR_C(frow[x_out], yscale);
150 const int v = (int)MULT_FIX_C(irow[x_out] - frac, fxy_scale);
151 dst[x_out] = (v > 255) ? 255u : (uint8_t)v;
152 irow[x_out] = frac; // new fractional start
153 }
154 } else {
155 for (x_out = 0; x_out < max_span; x_out += 8) {
156 LOAD_32x8(irow + x_out, in0, in1);
157 const uint32x4_t A0 = MULT_FIX(in0, fxy_scale_half);
158 const uint32x4_t A1 = MULT_FIX(in1, fxy_scale_half);
159 const uint16x4_t B0 = vmovn_u32(A0);
160 const uint16x4_t B1 = vmovn_u32(A1);
161 const uint8x8_t C = vqmovn_u16(vcombine_u16(B0, B1));
162 vst1_u8(dst + x_out, C);
163 STORE_32x8(zero, zero, irow + x_out);
164 }
165 for (; x_out < x_out_max; ++x_out) {
166 const int v = (int)MULT_FIX_C(irow[x_out], fxy_scale);
167 dst[x_out] = (v > 255) ? 255u : (uint8_t)v;
168 irow[x_out] = 0;
169 }
170 }
171}
172
173#undef MULT_FIX_FLOOR_C
174#undef MULT_FIX_C
175#undef MULT_FIX_FLOOR
176#undef MULT_FIX
177#undef ROUNDER
178
179//------------------------------------------------------------------------------
180
181extern void WebPRescalerDspInitNEON(void);
182
183WEBP_TSAN_IGNORE_FUNCTION void WebPRescalerDspInitNEON(void) {
184 WebPRescalerExportRowExpand = RescalerExportRowExpand_NEON;
185 WebPRescalerExportRowShrink = RescalerExportRowShrink_NEON;
186}
187
188#else // !WEBP_USE_NEON
189
190WEBP_DSP_INIT_STUB(WebPRescalerDspInitNEON)
191
192#endif // WEBP_USE_NEON
193