ab56b9841c
We use a standard set of strict compiler warnings with Clang and GCC to continuously test and maintain C89 conformance in the libjpeg API code. However, SIMD extensions need not comply with that. The Neon code specifically uses some C99isms, so disable -Wdeclaration-after-statement, -Wc99-extensions, and -Wpedantic in the scope of that code. Also modify the Neon feature tests so that they will succeed if any of the aforementioned compiler warnings are enabled.
194 lines
8.4 KiB
C
194 lines
8.4 KiB
C
/*
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* jcsample-neon.c - downsampling (Arm Neon)
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*
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* Copyright (C) 2020, Arm Limited. All Rights Reserved.
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*/
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#define JPEG_INTERNALS
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#include "../../jinclude.h"
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#include "../../jpeglib.h"
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#include "../../jsimd.h"
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#include "../../jdct.h"
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#include "../../jsimddct.h"
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#include "../jsimd.h"
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#include "align.h"
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#include "neon-compat.h"
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#include <arm_neon.h>
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ALIGN(16) static const uint8_t jsimd_h2_downsample_consts[] = {
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 0 */
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0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 1 */
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0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0E,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 2 */
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0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0D, 0x0D,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 3 */
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0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0C, 0x0C, 0x0C,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 4 */
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0x08, 0x09, 0x0A, 0x0B, 0x0B, 0x0B, 0x0B, 0x0B,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 5 */
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0x08, 0x09, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A, 0x0A,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 6 */
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0x08, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 7 */
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0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* Pad 8 */
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0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x06, /* Pad 9 */
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0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x05, 0x05, /* Pad 10 */
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0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
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0x00, 0x01, 0x02, 0x03, 0x04, 0x04, 0x04, 0x04, /* Pad 11 */
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0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
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0x00, 0x01, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, /* Pad 12 */
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0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
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0x00, 0x01, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, /* Pad 13 */
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0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
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0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, /* Pad 14 */
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0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* Pad 15 */
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
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};
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/* Downsample pixel values of a single component.
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* This version handles the common case of 2:1 horizontal and 1:1 vertical,
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* without smoothing.
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*/
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void jsimd_h2v1_downsample_neon(JDIMENSION image_width, int max_v_samp_factor,
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JDIMENSION v_samp_factor,
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JDIMENSION width_in_blocks,
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JSAMPARRAY input_data, JSAMPARRAY output_data)
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{
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JSAMPROW inptr, outptr;
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/* Load expansion mask to pad remaining elements of last DCT block. */
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const int mask_offset = 16 * ((width_in_blocks * 2 * DCTSIZE) - image_width);
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const uint8x16_t expand_mask =
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vld1q_u8(&jsimd_h2_downsample_consts[mask_offset]);
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/* Load bias pattern (alternating every pixel.) */
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/* { 0, 1, 0, 1, 0, 1, 0, 1 } */
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const uint16x8_t bias = vreinterpretq_u16_u32(vdupq_n_u32(0x00010000));
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unsigned i, outrow;
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for (outrow = 0; outrow < v_samp_factor; outrow++) {
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outptr = output_data[outrow];
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inptr = input_data[outrow];
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/* Downsample all but the last DCT block of pixels. */
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for (i = 0; i < width_in_blocks - 1; i++) {
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uint8x16_t pixels = vld1q_u8(inptr + i * 2 * DCTSIZE);
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/* Add adjacent pixel values, widen to 16-bit, and add bias. */
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uint16x8_t samples_u16 = vpadalq_u8(bias, pixels);
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/* Divide total by 2 and narrow to 8-bit. */
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uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 1);
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/* Store samples to memory. */
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vst1_u8(outptr + i * DCTSIZE, samples_u8);
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}
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/* Load pixels in last DCT block into a table. */
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uint8x16_t pixels = vld1q_u8(inptr + (width_in_blocks - 1) * 2 * DCTSIZE);
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#if defined(__aarch64__) || defined(_M_ARM64)
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/* Pad the empty elements with the value of the last pixel. */
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pixels = vqtbl1q_u8(pixels, expand_mask);
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#else
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uint8x8x2_t table = { { vget_low_u8(pixels), vget_high_u8(pixels) } };
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pixels = vcombine_u8(vtbl2_u8(table, vget_low_u8(expand_mask)),
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vtbl2_u8(table, vget_high_u8(expand_mask)));
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#endif
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/* Add adjacent pixel values, widen to 16-bit, and add bias. */
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uint16x8_t samples_u16 = vpadalq_u8(bias, pixels);
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/* Divide total by 2, narrow to 8-bit, and store. */
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uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 1);
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vst1_u8(outptr + (width_in_blocks - 1) * DCTSIZE, samples_u8);
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}
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}
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/* Downsample pixel values of a single component.
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* This version handles the standard case of 2:1 horizontal and 2:1 vertical,
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* without smoothing.
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*/
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void jsimd_h2v2_downsample_neon(JDIMENSION image_width, int max_v_samp_factor,
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JDIMENSION v_samp_factor,
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JDIMENSION width_in_blocks,
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JSAMPARRAY input_data, JSAMPARRAY output_data)
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{
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JSAMPROW inptr0, inptr1, outptr;
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/* Load expansion mask to pad remaining elements of last DCT block. */
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const int mask_offset = 16 * ((width_in_blocks * 2 * DCTSIZE) - image_width);
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const uint8x16_t expand_mask =
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vld1q_u8(&jsimd_h2_downsample_consts[mask_offset]);
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/* Load bias pattern (alternating every pixel.) */
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/* { 1, 2, 1, 2, 1, 2, 1, 2 } */
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const uint16x8_t bias = vreinterpretq_u16_u32(vdupq_n_u32(0x00020001));
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unsigned i, outrow;
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for (outrow = 0; outrow < v_samp_factor; outrow++) {
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outptr = output_data[outrow];
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inptr0 = input_data[outrow];
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inptr1 = input_data[outrow + 1];
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/* Downsample all but the last DCT block of pixels. */
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for (i = 0; i < width_in_blocks - 1; i++) {
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uint8x16_t pixels_r0 = vld1q_u8(inptr0 + i * 2 * DCTSIZE);
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uint8x16_t pixels_r1 = vld1q_u8(inptr1 + i * 2 * DCTSIZE);
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/* Add adjacent pixel values in row 0, widen to 16-bit, and add bias. */
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uint16x8_t samples_u16 = vpadalq_u8(bias, pixels_r0);
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/* Add adjacent pixel values in row 1, widen to 16-bit, and accumulate.
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*/
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samples_u16 = vpadalq_u8(samples_u16, pixels_r1);
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/* Divide total by 4 and narrow to 8-bit. */
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uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 2);
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/* Store samples to memory and increment pointers. */
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vst1_u8(outptr + i * DCTSIZE, samples_u8);
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}
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/* Load pixels in last DCT block into a table. */
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uint8x16_t pixels_r0 =
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vld1q_u8(inptr0 + (width_in_blocks - 1) * 2 * DCTSIZE);
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uint8x16_t pixels_r1 =
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vld1q_u8(inptr1 + (width_in_blocks - 1) * 2 * DCTSIZE);
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#if defined(__aarch64__) || defined(_M_ARM64)
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/* Pad the empty elements with the value of the last pixel. */
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pixels_r0 = vqtbl1q_u8(pixels_r0, expand_mask);
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pixels_r1 = vqtbl1q_u8(pixels_r1, expand_mask);
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#else
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uint8x8x2_t table_r0 =
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{ { vget_low_u8(pixels_r0), vget_high_u8(pixels_r0) } };
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uint8x8x2_t table_r1 =
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{ { vget_low_u8(pixels_r1), vget_high_u8(pixels_r1) } };
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pixels_r0 = vcombine_u8(vtbl2_u8(table_r0, vget_low_u8(expand_mask)),
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vtbl2_u8(table_r0, vget_high_u8(expand_mask)));
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pixels_r1 = vcombine_u8(vtbl2_u8(table_r1, vget_low_u8(expand_mask)),
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vtbl2_u8(table_r1, vget_high_u8(expand_mask)));
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#endif
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/* Add adjacent pixel values in row 0, widen to 16-bit, and add bias. */
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uint16x8_t samples_u16 = vpadalq_u8(bias, pixels_r0);
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/* Add adjacent pixel values in row 1, widen to 16-bit, and accumulate. */
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samples_u16 = vpadalq_u8(samples_u16, pixels_r1);
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/* Divide total by 4, narrow to 8-bit, and store. */
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uint8x8_t samples_u8 = vshrn_n_u16(samples_u16, 2);
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vst1_u8(outptr + (width_in_blocks - 1) * DCTSIZE, samples_u8);
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}
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}
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