1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkBitmapProcState.h"
9#include "SkBitmapProcState_filter.h"
10#include "SkColorPriv.h"
11#include "SkFilterProc.h"
12#include "SkPaint.h"
13#include "SkShader.h"   // for tilemodes
14#include "SkUtilsArm.h"
15
16// Required to ensure the table is part of the final binary.
17extern const SkBitmapProcState::SampleProc32 gSkBitmapProcStateSample32_neon[];
18
19#define   NAME_WRAP(x)  x ## _neon
20#include "SkBitmapProcState_filter_neon.h"
21#include "SkBitmapProcState_procs.h"
22
23const SkBitmapProcState::SampleProc32 gSkBitmapProcStateSample32_neon[] = {
24    S32_opaque_D32_nofilter_DXDY_neon,
25    S32_alpha_D32_nofilter_DXDY_neon,
26    S32_opaque_D32_nofilter_DX_neon,
27    S32_alpha_D32_nofilter_DX_neon,
28    S32_opaque_D32_filter_DXDY_neon,
29    S32_alpha_D32_filter_DXDY_neon,
30    S32_opaque_D32_filter_DX_neon,
31    S32_alpha_D32_filter_DX_neon,
32
33    S16_opaque_D32_nofilter_DXDY_neon,
34    S16_alpha_D32_nofilter_DXDY_neon,
35    S16_opaque_D32_nofilter_DX_neon,
36    S16_alpha_D32_nofilter_DX_neon,
37    S16_opaque_D32_filter_DXDY_neon,
38    S16_alpha_D32_filter_DXDY_neon,
39    S16_opaque_D32_filter_DX_neon,
40    S16_alpha_D32_filter_DX_neon,
41
42    SI8_opaque_D32_nofilter_DXDY_neon,
43    SI8_alpha_D32_nofilter_DXDY_neon,
44    SI8_opaque_D32_nofilter_DX_neon,
45    SI8_alpha_D32_nofilter_DX_neon,
46    SI8_opaque_D32_filter_DXDY_neon,
47    SI8_alpha_D32_filter_DXDY_neon,
48    SI8_opaque_D32_filter_DX_neon,
49    SI8_alpha_D32_filter_DX_neon,
50
51    S4444_opaque_D32_nofilter_DXDY_neon,
52    S4444_alpha_D32_nofilter_DXDY_neon,
53    S4444_opaque_D32_nofilter_DX_neon,
54    S4444_alpha_D32_nofilter_DX_neon,
55    S4444_opaque_D32_filter_DXDY_neon,
56    S4444_alpha_D32_filter_DXDY_neon,
57    S4444_opaque_D32_filter_DX_neon,
58    S4444_alpha_D32_filter_DX_neon,
59
60    // A8 treats alpha/opauqe the same (equally efficient)
61    SA8_alpha_D32_nofilter_DXDY_neon,
62    SA8_alpha_D32_nofilter_DXDY_neon,
63    SA8_alpha_D32_nofilter_DX_neon,
64    SA8_alpha_D32_nofilter_DX_neon,
65    SA8_alpha_D32_filter_DXDY_neon,
66    SA8_alpha_D32_filter_DXDY_neon,
67    SA8_alpha_D32_filter_DX_neon,
68    SA8_alpha_D32_filter_DX_neon,
69
70    // todo: possibly specialize on opaqueness
71    SG8_alpha_D32_nofilter_DXDY_neon,
72    SG8_alpha_D32_nofilter_DXDY_neon,
73    SG8_alpha_D32_nofilter_DX_neon,
74    SG8_alpha_D32_nofilter_DX_neon,
75    SG8_alpha_D32_filter_DXDY_neon,
76    SG8_alpha_D32_filter_DXDY_neon,
77    SG8_alpha_D32_filter_DX_neon,
78    SG8_alpha_D32_filter_DX_neon,
79};
80
81///////////////////////////////////////////////////////////////////////////////
82
83#include <arm_neon.h>
84#include "SkConvolver.h"
85
86// Convolves horizontally along a single row. The row data is given in
87// |srcData| and continues for the numValues() of the filter.
88void convolveHorizontally_neon(const unsigned char* srcData,
89                               const SkConvolutionFilter1D& filter,
90                               unsigned char* outRow,
91                               bool hasAlpha) {
92    // Loop over each pixel on this row in the output image.
93    int numValues = filter.numValues();
94    for (int outX = 0; outX < numValues; outX++) {
95        uint8x8_t coeff_mask0 = vcreate_u8(0x0100010001000100);
96        uint8x8_t coeff_mask1 = vcreate_u8(0x0302030203020302);
97        uint8x8_t coeff_mask2 = vcreate_u8(0x0504050405040504);
98        uint8x8_t coeff_mask3 = vcreate_u8(0x0706070607060706);
99        // Get the filter that determines the current output pixel.
100        int filterOffset, filterLength;
101        const SkConvolutionFilter1D::ConvolutionFixed* filterValues =
102            filter.FilterForValue(outX, &filterOffset, &filterLength);
103
104        // Compute the first pixel in this row that the filter affects. It will
105        // touch |filterLength| pixels (4 bytes each) after this.
106        const unsigned char* rowToFilter = &srcData[filterOffset * 4];
107
108        // Apply the filter to the row to get the destination pixel in |accum|.
109        int32x4_t accum = vdupq_n_s32(0);
110        for (int filterX = 0; filterX < filterLength >> 2; filterX++) {
111            // Load 4 coefficients
112            int16x4_t coeffs, coeff0, coeff1, coeff2, coeff3;
113            coeffs = vld1_s16(filterValues);
114            coeff0 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask0));
115            coeff1 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask1));
116            coeff2 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask2));
117            coeff3 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask3));
118
119            // Load pixels and calc
120            uint8x16_t pixels = vld1q_u8(rowToFilter);
121            int16x8_t p01_16 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(pixels)));
122            int16x8_t p23_16 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(pixels)));
123
124            int16x4_t p0_src = vget_low_s16(p01_16);
125            int16x4_t p1_src = vget_high_s16(p01_16);
126            int16x4_t p2_src = vget_low_s16(p23_16);
127            int16x4_t p3_src = vget_high_s16(p23_16);
128
129            int32x4_t p0 = vmull_s16(p0_src, coeff0);
130            int32x4_t p1 = vmull_s16(p1_src, coeff1);
131            int32x4_t p2 = vmull_s16(p2_src, coeff2);
132            int32x4_t p3 = vmull_s16(p3_src, coeff3);
133
134            accum += p0;
135            accum += p1;
136            accum += p2;
137            accum += p3;
138
139            // Advance the pointers
140            rowToFilter += 16;
141            filterValues += 4;
142        }
143        int r = filterLength & 3;
144        if (r) {
145            const uint16_t mask[4][4] = {
146                {0, 0, 0, 0},
147                {0xFFFF, 0, 0, 0},
148                {0xFFFF, 0xFFFF, 0, 0},
149                {0xFFFF, 0xFFFF, 0xFFFF, 0}
150            };
151            uint16x4_t coeffs;
152            int16x4_t coeff0, coeff1, coeff2;
153            coeffs = vld1_u16(reinterpret_cast<const uint16_t*>(filterValues));
154            coeffs &= vld1_u16(&mask[r][0]);
155            coeff0 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_u16(coeffs), coeff_mask0));
156            coeff1 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_u16(coeffs), coeff_mask1));
157            coeff2 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_u16(coeffs), coeff_mask2));
158
159            // Load pixels and calc
160            uint8x16_t pixels = vld1q_u8(rowToFilter);
161            int16x8_t p01_16 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(pixels)));
162            int16x8_t p23_16 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(pixels)));
163            int32x4_t p0 = vmull_s16(vget_low_s16(p01_16), coeff0);
164            int32x4_t p1 = vmull_s16(vget_high_s16(p01_16), coeff1);
165            int32x4_t p2 = vmull_s16(vget_low_s16(p23_16), coeff2);
166
167            accum += p0;
168            accum += p1;
169            accum += p2;
170        }
171
172        // Bring this value back in range. All of the filter scaling factors
173        // are in fixed point with kShiftBits bits of fractional part.
174        accum = vshrq_n_s32(accum, SkConvolutionFilter1D::kShiftBits);
175
176        // Pack and store the new pixel.
177        int16x4_t accum16 = vqmovn_s32(accum);
178        uint8x8_t accum8 = vqmovun_s16(vcombine_s16(accum16, accum16));
179        vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow), vreinterpret_u32_u8(accum8), 0);
180        outRow += 4;
181    }
182}
183
184// Does vertical convolution to produce one output row. The filter values and
185// length are given in the first two parameters. These are applied to each
186// of the rows pointed to in the |sourceDataRows| array, with each row
187// being |pixelWidth| wide.
188//
189// The output must have room for |pixelWidth * 4| bytes.
190template<bool hasAlpha>
191void convolveVertically_neon(const SkConvolutionFilter1D::ConvolutionFixed* filterValues,
192                             int filterLength,
193                             unsigned char* const* sourceDataRows,
194                             int pixelWidth,
195                             unsigned char* outRow) {
196    int width = pixelWidth & ~3;
197
198    int32x4_t accum0, accum1, accum2, accum3;
199    int16x4_t coeff16;
200
201    // Output four pixels per iteration (16 bytes).
202    for (int outX = 0; outX < width; outX += 4) {
203
204        // Accumulated result for each pixel. 32 bits per RGBA channel.
205        accum0 = accum1 = accum2 = accum3 = vdupq_n_s32(0);
206
207        // Convolve with one filter coefficient per iteration.
208        for (int filterY = 0; filterY < filterLength; filterY++) {
209
210            // Duplicate the filter coefficient 4 times.
211            // [16] cj cj cj cj
212            coeff16 = vdup_n_s16(filterValues[filterY]);
213
214            // Load four pixels (16 bytes) together.
215            // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0
216            uint8x16_t src8 = vld1q_u8(&sourceDataRows[filterY][outX << 2]);
217
218            int16x8_t src16_01 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(src8)));
219            int16x8_t src16_23 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(src8)));
220            int16x4_t src16_0 = vget_low_s16(src16_01);
221            int16x4_t src16_1 = vget_high_s16(src16_01);
222            int16x4_t src16_2 = vget_low_s16(src16_23);
223            int16x4_t src16_3 = vget_high_s16(src16_23);
224
225            accum0 += vmull_s16(src16_0, coeff16);
226            accum1 += vmull_s16(src16_1, coeff16);
227            accum2 += vmull_s16(src16_2, coeff16);
228            accum3 += vmull_s16(src16_3, coeff16);
229        }
230
231        // Shift right for fixed point implementation.
232        accum0 = vshrq_n_s32(accum0, SkConvolutionFilter1D::kShiftBits);
233        accum1 = vshrq_n_s32(accum1, SkConvolutionFilter1D::kShiftBits);
234        accum2 = vshrq_n_s32(accum2, SkConvolutionFilter1D::kShiftBits);
235        accum3 = vshrq_n_s32(accum3, SkConvolutionFilter1D::kShiftBits);
236
237        // Packing 32 bits |accum| to 16 bits per channel (signed saturation).
238        // [16] a1 b1 g1 r1 a0 b0 g0 r0
239        int16x8_t accum16_0 = vcombine_s16(vqmovn_s32(accum0), vqmovn_s32(accum1));
240        // [16] a3 b3 g3 r3 a2 b2 g2 r2
241        int16x8_t accum16_1 = vcombine_s16(vqmovn_s32(accum2), vqmovn_s32(accum3));
242
243        // Packing 16 bits |accum| to 8 bits per channel (unsigned saturation).
244        // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0
245        uint8x16_t accum8 = vcombine_u8(vqmovun_s16(accum16_0), vqmovun_s16(accum16_1));
246
247        if (hasAlpha) {
248            // Compute the max(ri, gi, bi) for each pixel.
249            // [8] xx a3 b3 g3 xx a2 b2 g2 xx a1 b1 g1 xx a0 b0 g0
250            uint8x16_t a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 8));
251            // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0
252            uint8x16_t b = vmaxq_u8(a, accum8); // Max of r and g
253            // [8] xx xx a3 b3 xx xx a2 b2 xx xx a1 b1 xx xx a0 b0
254            a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 16));
255            // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0
256            b = vmaxq_u8(a, b); // Max of r and g and b.
257            // [8] max3 00 00 00 max2 00 00 00 max1 00 00 00 max0 00 00 00
258            b = vreinterpretq_u8_u32(vshlq_n_u32(vreinterpretq_u32_u8(b), 24));
259
260            // Make sure the value of alpha channel is always larger than maximum
261            // value of color channels.
262            accum8 = vmaxq_u8(b, accum8);
263        } else {
264            // Set value of alpha channels to 0xFF.
265            accum8 = vreinterpretq_u8_u32(vreinterpretq_u32_u8(accum8) | vdupq_n_u32(0xFF000000));
266        }
267
268        // Store the convolution result (16 bytes) and advance the pixel pointers.
269        vst1q_u8(outRow, accum8);
270        outRow += 16;
271    }
272
273    // Process the leftovers when the width of the output is not divisible
274    // by 4, that is at most 3 pixels.
275    int r = pixelWidth & 3;
276    if (r) {
277
278        accum0 = accum1 = accum2 = vdupq_n_s32(0);
279
280        for (int filterY = 0; filterY < filterLength; ++filterY) {
281            coeff16 = vdup_n_s16(filterValues[filterY]);
282
283            // [8] a3 b3 g3 r3 a2 b2 g2 r2 a1 b1 g1 r1 a0 b0 g0 r0
284            uint8x16_t src8 = vld1q_u8(&sourceDataRows[filterY][width << 2]);
285
286            int16x8_t src16_01 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(src8)));
287            int16x8_t src16_23 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(src8)));
288            int16x4_t src16_0 = vget_low_s16(src16_01);
289            int16x4_t src16_1 = vget_high_s16(src16_01);
290            int16x4_t src16_2 = vget_low_s16(src16_23);
291
292            accum0 += vmull_s16(src16_0, coeff16);
293            accum1 += vmull_s16(src16_1, coeff16);
294            accum2 += vmull_s16(src16_2, coeff16);
295        }
296
297        accum0 = vshrq_n_s32(accum0, SkConvolutionFilter1D::kShiftBits);
298        accum1 = vshrq_n_s32(accum1, SkConvolutionFilter1D::kShiftBits);
299        accum2 = vshrq_n_s32(accum2, SkConvolutionFilter1D::kShiftBits);
300
301        int16x8_t accum16_0 = vcombine_s16(vqmovn_s32(accum0), vqmovn_s32(accum1));
302        int16x8_t accum16_1 = vcombine_s16(vqmovn_s32(accum2), vqmovn_s32(accum2));
303
304        uint8x16_t accum8 = vcombine_u8(vqmovun_s16(accum16_0), vqmovun_s16(accum16_1));
305
306        if (hasAlpha) {
307            // Compute the max(ri, gi, bi) for each pixel.
308            // [8] xx a3 b3 g3 xx a2 b2 g2 xx a1 b1 g1 xx a0 b0 g0
309            uint8x16_t a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 8));
310            // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0
311            uint8x16_t b = vmaxq_u8(a, accum8); // Max of r and g
312            // [8] xx xx a3 b3 xx xx a2 b2 xx xx a1 b1 xx xx a0 b0
313            a = vreinterpretq_u8_u32(vshrq_n_u32(vreinterpretq_u32_u8(accum8), 16));
314            // [8] xx xx xx max3 xx xx xx max2 xx xx xx max1 xx xx xx max0
315            b = vmaxq_u8(a, b); // Max of r and g and b.
316            // [8] max3 00 00 00 max2 00 00 00 max1 00 00 00 max0 00 00 00
317            b = vreinterpretq_u8_u32(vshlq_n_u32(vreinterpretq_u32_u8(b), 24));
318
319            // Make sure the value of alpha channel is always larger than maximum
320            // value of color channels.
321            accum8 = vmaxq_u8(b, accum8);
322        } else {
323            // Set value of alpha channels to 0xFF.
324            accum8 = vreinterpretq_u8_u32(vreinterpretq_u32_u8(accum8) | vdupq_n_u32(0xFF000000));
325        }
326
327        switch(r) {
328        case 1:
329            vst1q_lane_u32(reinterpret_cast<uint32_t*>(outRow), vreinterpretq_u32_u8(accum8), 0);
330            break;
331        case 2:
332            vst1_u32(reinterpret_cast<uint32_t*>(outRow),
333                     vreinterpret_u32_u8(vget_low_u8(accum8)));
334            break;
335        case 3:
336            vst1_u32(reinterpret_cast<uint32_t*>(outRow),
337                     vreinterpret_u32_u8(vget_low_u8(accum8)));
338            vst1q_lane_u32(reinterpret_cast<uint32_t*>(outRow+8), vreinterpretq_u32_u8(accum8), 2);
339            break;
340        }
341    }
342}
343
344void convolveVertically_neon(const SkConvolutionFilter1D::ConvolutionFixed* filterValues,
345                             int filterLength,
346                             unsigned char* const* sourceDataRows,
347                             int pixelWidth,
348                             unsigned char* outRow,
349                             bool sourceHasAlpha) {
350    if (sourceHasAlpha) {
351        convolveVertically_neon<true>(filterValues, filterLength,
352                                      sourceDataRows, pixelWidth,
353                                      outRow);
354    } else {
355        convolveVertically_neon<false>(filterValues, filterLength,
356                                       sourceDataRows, pixelWidth,
357                                       outRow);
358    }
359}
360
361// Convolves horizontally along four rows. The row data is given in
362// |src_data| and continues for the num_values() of the filter.
363// The algorithm is almost same as |ConvolveHorizontally_SSE2|. Please
364// refer to that function for detailed comments.
365void convolve4RowsHorizontally_neon(const unsigned char* srcData[4],
366                                    const SkConvolutionFilter1D& filter,
367                                    unsigned char* outRow[4],
368                                    size_t outRowBytes) {
369
370    uint8x8_t coeff_mask0 = vcreate_u8(0x0100010001000100);
371    uint8x8_t coeff_mask1 = vcreate_u8(0x0302030203020302);
372    uint8x8_t coeff_mask2 = vcreate_u8(0x0504050405040504);
373    uint8x8_t coeff_mask3 = vcreate_u8(0x0706070607060706);
374    int num_values = filter.numValues();
375
376    int filterOffset, filterLength;
377    // |mask| will be used to decimate all extra filter coefficients that are
378    // loaded by SIMD when |filter_length| is not divisible by 4.
379    // mask[0] is not used in following algorithm.
380    const uint16_t mask[4][4] = {
381        {0, 0, 0, 0},
382        {0xFFFF, 0, 0, 0},
383        {0xFFFF, 0xFFFF, 0, 0},
384        {0xFFFF, 0xFFFF, 0xFFFF, 0}
385    };
386
387    // Output one pixel each iteration, calculating all channels (RGBA) together.
388    for (int outX = 0; outX < num_values; outX++) {
389
390        const SkConvolutionFilter1D::ConvolutionFixed* filterValues =
391        filter.FilterForValue(outX, &filterOffset, &filterLength);
392
393        // four pixels in a column per iteration.
394        int32x4_t accum0 = vdupq_n_s32(0);
395        int32x4_t accum1 = vdupq_n_s32(0);
396        int32x4_t accum2 = vdupq_n_s32(0);
397        int32x4_t accum3 = vdupq_n_s32(0);
398
399        int start = (filterOffset<<2);
400
401        // We will load and accumulate with four coefficients per iteration.
402        for (int filter_x = 0; filter_x < (filterLength >> 2); filter_x++) {
403            int16x4_t coeffs, coeff0, coeff1, coeff2, coeff3;
404
405            coeffs = vld1_s16(filterValues);
406            coeff0 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask0));
407            coeff1 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask1));
408            coeff2 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask2));
409            coeff3 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask3));
410
411            uint8x16_t pixels;
412            int16x8_t p01_16, p23_16;
413            int32x4_t p0, p1, p2, p3;
414
415
416#define ITERATION(src, accum)                                       \
417    pixels = vld1q_u8(src);                                         \
418    p01_16 = vreinterpretq_s16_u16(vmovl_u8(vget_low_u8(pixels)));  \
419    p23_16 = vreinterpretq_s16_u16(vmovl_u8(vget_high_u8(pixels))); \
420    p0 = vmull_s16(vget_low_s16(p01_16), coeff0);                   \
421    p1 = vmull_s16(vget_high_s16(p01_16), coeff1);                  \
422    p2 = vmull_s16(vget_low_s16(p23_16), coeff2);                   \
423    p3 = vmull_s16(vget_high_s16(p23_16), coeff3);                  \
424    accum += p0;                                                    \
425    accum += p1;                                                    \
426    accum += p2;                                                    \
427    accum += p3
428
429            ITERATION(srcData[0] + start, accum0);
430            ITERATION(srcData[1] + start, accum1);
431            ITERATION(srcData[2] + start, accum2);
432            ITERATION(srcData[3] + start, accum3);
433
434            start += 16;
435            filterValues += 4;
436        }
437
438        int r = filterLength & 3;
439        if (r) {
440            int16x4_t coeffs, coeff0, coeff1, coeff2, coeff3;
441            coeffs = vld1_s16(filterValues);
442            coeffs &= vreinterpret_s16_u16(vld1_u16(&mask[r][0]));
443            coeff0 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask0));
444            coeff1 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask1));
445            coeff2 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask2));
446            coeff3 = vreinterpret_s16_u8(vtbl1_u8(vreinterpret_u8_s16(coeffs), coeff_mask3));
447
448            uint8x16_t pixels;
449            int16x8_t p01_16, p23_16;
450            int32x4_t p0, p1, p2, p3;
451
452            ITERATION(srcData[0] + start, accum0);
453            ITERATION(srcData[1] + start, accum1);
454            ITERATION(srcData[2] + start, accum2);
455            ITERATION(srcData[3] + start, accum3);
456        }
457
458        int16x4_t accum16;
459        uint8x8_t res0, res1, res2, res3;
460
461#define PACK_RESULT(accum, res)                                         \
462        accum = vshrq_n_s32(accum, SkConvolutionFilter1D::kShiftBits);  \
463        accum16 = vqmovn_s32(accum);                                    \
464        res = vqmovun_s16(vcombine_s16(accum16, accum16));
465
466        PACK_RESULT(accum0, res0);
467        PACK_RESULT(accum1, res1);
468        PACK_RESULT(accum2, res2);
469        PACK_RESULT(accum3, res3);
470
471        vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow[0]), vreinterpret_u32_u8(res0), 0);
472        vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow[1]), vreinterpret_u32_u8(res1), 0);
473        vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow[2]), vreinterpret_u32_u8(res2), 0);
474        vst1_lane_u32(reinterpret_cast<uint32_t*>(outRow[3]), vreinterpret_u32_u8(res3), 0);
475        outRow[0] += 4;
476        outRow[1] += 4;
477        outRow[2] += 4;
478        outRow[3] += 4;
479    }
480}
481
482void applySIMDPadding_neon(SkConvolutionFilter1D *filter) {
483    // Padding |paddingCount| of more dummy coefficients after the coefficients
484    // of last filter to prevent SIMD instructions which load 8 or 16 bytes
485    // together to access invalid memory areas. We are not trying to align the
486    // coefficients right now due to the opaqueness of <vector> implementation.
487    // This has to be done after all |AddFilter| calls.
488    for (int i = 0; i < 8; ++i) {
489        filter->addFilterValue(static_cast<SkConvolutionFilter1D::ConvolutionFixed>(0));
490    }
491}
492
493void platformConvolutionProcs_arm_neon(SkConvolutionProcs* procs) {
494    procs->fExtraHorizontalReads = 3;
495    procs->fConvolveVertically = &convolveVertically_neon;
496    procs->fConvolve4RowsHorizontally = &convolve4RowsHorizontally_neon;
497    procs->fConvolveHorizontally = &convolveHorizontally_neon;
498    procs->fApplySIMDPadding = &applySIMDPadding_neon;
499}
500