Neon: Intrinsics impl. of fast integer Inverse DCT

The previous AArch32 GAS implementation is retained by default when
using GCC, in order to avoid a performance regression.  The intrinsics
implementation can be forced on or off using the new NEON_INTRINSICS
CMake variable.  The previous AArch64 GAS implementation has been
removed, since the intrinsics implementation provides the same or better
performance.
This commit is contained in:
Jonathan Wright
2018-09-25 18:20:25 +01:00
committed by DRC
parent 2acfb93c94
commit 2c6b68e283
4 changed files with 479 additions and 237 deletions

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@@ -270,6 +270,9 @@ set(SIMD_SOURCES arm/jcgray-neon.c arm/jcsample-neon.c arm/jdsample-neon.c
if(NEON_INTRINSICS)
set(SIMD_SOURCES ${SIMD_SOURCES} arm/jccolor-neon.c)
endif()
if(NEON_INTRINSICS OR BITS EQUAL 64)
set(SIMD_SOURCES ${SIMD_SOURCES} arm/jidctfst-neon.c)
endif()
if(NEON_INTRINSICS OR BITS EQUAL 32)
set(SIMD_SOURCES ${SIMD_SOURCES} arm/aarch${BITS}/jchuff-neon.c
arm/jdcolor-neon.c arm/jfdctint-neon.c)

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@@ -677,6 +677,8 @@ asm_function jsimd_idct_islow_neon
.unreq ROW7R
#ifndef NEON_INTRINSICS
/*****************************************************************************/
/*
@@ -900,6 +902,8 @@ asm_function jsimd_idct_ifast_neon
.unreq TMP3
.unreq TMP4
#endif /* NEON_INTRINSICS */
/*****************************************************************************/

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@@ -86,15 +86,6 @@ Ljsimd_idct_islow_neon_consts:
#undef F_2_562
#undef F_3_072
/* Constants for jsimd_idct_ifast_neon() */
.balign 16
Ljsimd_idct_ifast_neon_consts:
.short (277 * 128 - 256 * 128) /* XFIX_1_082392200 */
.short (362 * 128 - 256 * 128) /* XFIX_1_414213562 */
.short (473 * 128 - 256 * 128) /* XFIX_1_847759065 */
.short (669 * 128 - 512 * 128) /* XFIX_2_613125930 */
/* Constants for jsimd_idct_4x4_neon() and jsimd_idct_2x2_neon() */
#define CONST_BITS 13
@@ -957,234 +948,6 @@ asm_function jsimd_idct_islow_neon
#undef XFIX_P_3_072
/*****************************************************************************/
/*
* jsimd_idct_ifast_neon
*
* This function contains a fast, not so accurate integer implementation of
* the inverse DCT (Discrete Cosine Transform). It uses the same calculations
* and produces exactly the same output as IJG's original 'jpeg_idct_ifast'
* function from jidctfst.c
*
* Normally 1-D AAN DCT needs 5 multiplications and 29 additions.
* But in Arm Neon case some extra additions are required because VQDMULH
* instruction can't handle the constants larger than 1. So the expressions
* like "x * 1.082392200" have to be converted to "x * 0.082392200 + x",
* which introduces an extra addition. Overall, there are 6 extra additions
* per 1-D IDCT pass, totalling to 5 VQDMULH and 35 VADD/VSUB instructions.
*/
#define XFIX_1_082392200 v0.h[0]
#define XFIX_1_414213562 v0.h[1]
#define XFIX_1_847759065 v0.h[2]
#define XFIX_2_613125930 v0.h[3]
asm_function jsimd_idct_ifast_neon
DCT_TABLE .req x0
COEF_BLOCK .req x1
OUTPUT_BUF .req x2
OUTPUT_COL .req x3
TMP1 .req x0
TMP2 .req x1
TMP3 .req x9
TMP4 .req x10
TMP5 .req x11
TMP6 .req x12
TMP7 .req x13
TMP8 .req x14
/* OUTPUT_COL is a JDIMENSION (unsigned int) argument, so the ABI doesn't
guarantee that the upper (unused) 32 bits of x3 are valid. This
instruction ensures that those bits are set to zero. */
uxtw x3, w3
/* Load and dequantize coefficients into Neon registers
* with the following allocation:
* 0 1 2 3 | 4 5 6 7
* ---------+--------
* 0 | d16 | d17 ( v16.8h )
* 1 | d18 | d19 ( v17.8h )
* 2 | d20 | d21 ( v18.8h )
* 3 | d22 | d23 ( v19.8h )
* 4 | d24 | d25 ( v20.8h )
* 5 | d26 | d27 ( v21.8h )
* 6 | d28 | d29 ( v22.8h )
* 7 | d30 | d31 ( v23.8h )
*/
/* Save Neon registers used in fast IDCT */
get_symbol_loc TMP5, Ljsimd_idct_ifast_neon_consts
ld1 {v16.8h, v17.8h}, [COEF_BLOCK], 32
ld1 {v0.8h, v1.8h}, [DCT_TABLE], 32
ld1 {v18.8h, v19.8h}, [COEF_BLOCK], 32
mul v16.8h, v16.8h, v0.8h
ld1 {v2.8h, v3.8h}, [DCT_TABLE], 32
mul v17.8h, v17.8h, v1.8h
ld1 {v20.8h, v21.8h}, [COEF_BLOCK], 32
mul v18.8h, v18.8h, v2.8h
ld1 {v0.8h, v1.8h}, [DCT_TABLE], 32
mul v19.8h, v19.8h, v3.8h
ld1 {v22.8h, v23.8h}, [COEF_BLOCK], 32
mul v20.8h, v20.8h, v0.8h
ld1 {v2.8h, v3.8h}, [DCT_TABLE], 32
mul v22.8h, v22.8h, v2.8h
mul v21.8h, v21.8h, v1.8h
ld1 {v0.4h}, [TMP5] /* load constants */
mul v23.8h, v23.8h, v3.8h
/* 1-D IDCT, pass 1 */
sub v2.8h, v18.8h, v22.8h
add v22.8h, v18.8h, v22.8h
sub v1.8h, v19.8h, v21.8h
add v21.8h, v19.8h, v21.8h
sub v5.8h, v17.8h, v23.8h
add v23.8h, v17.8h, v23.8h
sqdmulh v4.8h, v2.8h, XFIX_1_414213562
sqdmulh v6.8h, v1.8h, XFIX_2_613125930
add v3.8h, v1.8h, v1.8h
sub v1.8h, v5.8h, v1.8h
add v18.8h, v2.8h, v4.8h
sqdmulh v4.8h, v1.8h, XFIX_1_847759065
sub v2.8h, v23.8h, v21.8h
add v3.8h, v3.8h, v6.8h
sqdmulh v6.8h, v2.8h, XFIX_1_414213562
add v1.8h, v1.8h, v4.8h
sqdmulh v4.8h, v5.8h, XFIX_1_082392200
sub v18.8h, v18.8h, v22.8h
add v2.8h, v2.8h, v6.8h
sub v6.8h, v16.8h, v20.8h
add v20.8h, v16.8h, v20.8h
add v17.8h, v5.8h, v4.8h
add v5.8h, v6.8h, v18.8h
sub v18.8h, v6.8h, v18.8h
add v6.8h, v23.8h, v21.8h
add v16.8h, v20.8h, v22.8h
sub v3.8h, v6.8h, v3.8h
sub v20.8h, v20.8h, v22.8h
sub v3.8h, v3.8h, v1.8h
sub v1.8h, v17.8h, v1.8h
add v2.8h, v3.8h, v2.8h
sub v23.8h, v16.8h, v6.8h
add v1.8h, v1.8h, v2.8h
add v16.8h, v16.8h, v6.8h
add v22.8h, v5.8h, v3.8h
sub v17.8h, v5.8h, v3.8h
sub v21.8h, v18.8h, v2.8h
add v18.8h, v18.8h, v2.8h
sub v19.8h, v20.8h, v1.8h
add v20.8h, v20.8h, v1.8h
transpose_8x8 v16, v17, v18, v19, v20, v21, v22, v23, v28, v29, v30, v31
/* 1-D IDCT, pass 2 */
sub v2.8h, v18.8h, v22.8h
add v22.8h, v18.8h, v22.8h
sub v1.8h, v19.8h, v21.8h
add v21.8h, v19.8h, v21.8h
sub v5.8h, v17.8h, v23.8h
add v23.8h, v17.8h, v23.8h
sqdmulh v4.8h, v2.8h, XFIX_1_414213562
sqdmulh v6.8h, v1.8h, XFIX_2_613125930
add v3.8h, v1.8h, v1.8h
sub v1.8h, v5.8h, v1.8h
add v18.8h, v2.8h, v4.8h
sqdmulh v4.8h, v1.8h, XFIX_1_847759065
sub v2.8h, v23.8h, v21.8h
add v3.8h, v3.8h, v6.8h
sqdmulh v6.8h, v2.8h, XFIX_1_414213562
add v1.8h, v1.8h, v4.8h
sqdmulh v4.8h, v5.8h, XFIX_1_082392200
sub v18.8h, v18.8h, v22.8h
add v2.8h, v2.8h, v6.8h
sub v6.8h, v16.8h, v20.8h
add v20.8h, v16.8h, v20.8h
add v17.8h, v5.8h, v4.8h
add v5.8h, v6.8h, v18.8h
sub v18.8h, v6.8h, v18.8h
add v6.8h, v23.8h, v21.8h
add v16.8h, v20.8h, v22.8h
sub v3.8h, v6.8h, v3.8h
sub v20.8h, v20.8h, v22.8h
sub v3.8h, v3.8h, v1.8h
sub v1.8h, v17.8h, v1.8h
add v2.8h, v3.8h, v2.8h
sub v23.8h, v16.8h, v6.8h
add v1.8h, v1.8h, v2.8h
add v16.8h, v16.8h, v6.8h
add v22.8h, v5.8h, v3.8h
sub v17.8h, v5.8h, v3.8h
sub v21.8h, v18.8h, v2.8h
add v18.8h, v18.8h, v2.8h
sub v19.8h, v20.8h, v1.8h
add v20.8h, v20.8h, v1.8h
/* Descale to 8-bit and range limit */
movi v0.16b, #0x80
/* Prepare pointers (dual-issue with Neon instructions) */
ldp TMP1, TMP2, [OUTPUT_BUF], 16
sqshrn v28.8b, v16.8h, #5
ldp TMP3, TMP4, [OUTPUT_BUF], 16
sqshrn v29.8b, v17.8h, #5
add TMP1, TMP1, OUTPUT_COL
sqshrn v30.8b, v18.8h, #5
add TMP2, TMP2, OUTPUT_COL
sqshrn v31.8b, v19.8h, #5
add TMP3, TMP3, OUTPUT_COL
sqshrn2 v28.16b, v20.8h, #5
add TMP4, TMP4, OUTPUT_COL
sqshrn2 v29.16b, v21.8h, #5
ldp TMP5, TMP6, [OUTPUT_BUF], 16
sqshrn2 v30.16b, v22.8h, #5
ldp TMP7, TMP8, [OUTPUT_BUF], 16
sqshrn2 v31.16b, v23.8h, #5
add TMP5, TMP5, OUTPUT_COL
add v16.16b, v28.16b, v0.16b
add TMP6, TMP6, OUTPUT_COL
add v18.16b, v29.16b, v0.16b
add TMP7, TMP7, OUTPUT_COL
add v20.16b, v30.16b, v0.16b
add TMP8, TMP8, OUTPUT_COL
add v22.16b, v31.16b, v0.16b
/* Transpose the final 8-bit samples */
trn1 v28.16b, v16.16b, v18.16b
trn1 v30.16b, v20.16b, v22.16b
trn2 v29.16b, v16.16b, v18.16b
trn2 v31.16b, v20.16b, v22.16b
trn1 v16.8h, v28.8h, v30.8h
trn2 v18.8h, v28.8h, v30.8h
trn1 v20.8h, v29.8h, v31.8h
trn2 v22.8h, v29.8h, v31.8h
uzp1 v28.4s, v16.4s, v18.4s
uzp2 v30.4s, v16.4s, v18.4s
uzp1 v29.4s, v20.4s, v22.4s
uzp2 v31.4s, v20.4s, v22.4s
/* Store results to the output buffer */
st1 {v28.d}[0], [TMP1]
st1 {v29.d}[0], [TMP2]
st1 {v28.d}[1], [TMP3]
st1 {v29.d}[1], [TMP4]
st1 {v30.d}[0], [TMP5]
st1 {v31.d}[0], [TMP6]
st1 {v30.d}[1], [TMP7]
st1 {v31.d}[1], [TMP8]
blr x30
.unreq DCT_TABLE
.unreq COEF_BLOCK
.unreq OUTPUT_BUF
.unreq OUTPUT_COL
.unreq TMP1
.unreq TMP2
.unreq TMP3
.unreq TMP4
.unreq TMP5
.unreq TMP6
.unreq TMP7
.unreq TMP8
/*****************************************************************************/
/*

472
simd/arm/jidctfst-neon.c Normal file
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@@ -0,0 +1,472 @@
/*
* jidctfst-neon.c - fast integer IDCT (Arm Neon)
*
* Copyright (C) 2020, Arm Limited. All Rights Reserved.
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#define JPEG_INTERNALS
#include "../../jinclude.h"
#include "../../jpeglib.h"
#include "../../jsimd.h"
#include "../../jdct.h"
#include "../../jsimddct.h"
#include "../jsimd.h"
#include "align.h"
#include <arm_neon.h>
/* jsimd_idct_ifast_neon() performs dequantization and a fast, not so accurate
* inverse DCT (Discrete Cosine Transform) on one block of coefficients. It
* uses the same calculations and produces exactly the same output as IJG's
* original jpeg_idct_ifast() function, which can be found in jidctfst.c.
*
* Scaled integer constants are used to avoid floating-point arithmetic:
* 0.082392200 = 2688 * 2^-15
* 0.414213562 = 13568 * 2^-15
* 0.847759065 = 27776 * 2^-15
* 0.613125930 = 20096 * 2^-15
*
* See jidctfst.c for further details of the IDCT algorithm. Where possible,
* the variable names and comments here in jsimd_idct_ifast_neon() match up
* with those in jpeg_idct_ifast().
*/
#define PASS1_BITS 2
#define F_0_082 2688
#define F_0_414 13568
#define F_0_847 27776
#define F_0_613 20096
ALIGN(16) static const int16_t jsimd_idct_ifast_neon_consts[] = {
F_0_082, F_0_414, F_0_847, F_0_613
};
void jsimd_idct_ifast_neon(void *dct_table, JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
IFAST_MULT_TYPE *quantptr = dct_table;
/* Load DCT coefficients. */
int16x8_t row0 = vld1q_s16(coef_block + 0 * DCTSIZE);
int16x8_t row1 = vld1q_s16(coef_block + 1 * DCTSIZE);
int16x8_t row2 = vld1q_s16(coef_block + 2 * DCTSIZE);
int16x8_t row3 = vld1q_s16(coef_block + 3 * DCTSIZE);
int16x8_t row4 = vld1q_s16(coef_block + 4 * DCTSIZE);
int16x8_t row5 = vld1q_s16(coef_block + 5 * DCTSIZE);
int16x8_t row6 = vld1q_s16(coef_block + 6 * DCTSIZE);
int16x8_t row7 = vld1q_s16(coef_block + 7 * DCTSIZE);
/* Load quantization table values for DC coefficients. */
int16x8_t quant_row0 = vld1q_s16(quantptr + 0 * DCTSIZE);
/* Dequantize DC coefficients. */
row0 = vmulq_s16(row0, quant_row0);
/* Construct bitmap to test if all AC coefficients are 0. */
int16x8_t bitmap = vorrq_s16(row1, row2);
bitmap = vorrq_s16(bitmap, row3);
bitmap = vorrq_s16(bitmap, row4);
bitmap = vorrq_s16(bitmap, row5);
bitmap = vorrq_s16(bitmap, row6);
bitmap = vorrq_s16(bitmap, row7);
int64_t left_ac_bitmap = vgetq_lane_s64(vreinterpretq_s64_s16(bitmap), 0);
int64_t right_ac_bitmap = vgetq_lane_s64(vreinterpretq_s64_s16(bitmap), 1);
/* Load IDCT conversion constants. */
const int16x4_t consts = vld1_s16(jsimd_idct_ifast_neon_consts);
if (left_ac_bitmap == 0 && right_ac_bitmap == 0) {
/* All AC coefficients are zero.
* Compute DC values and duplicate into vectors.
*/
int16x8_t dcval = row0;
row1 = dcval;
row2 = dcval;
row3 = dcval;
row4 = dcval;
row5 = dcval;
row6 = dcval;
row7 = dcval;
} else if (left_ac_bitmap == 0) {
/* AC coefficients are zero for columns 0, 1, 2, and 3.
* Use DC values for these columns.
*/
int16x4_t dcval = vget_low_s16(row0);
/* Commence regular fast IDCT computation for columns 4, 5, 6, and 7. */
/* Load quantization table. */
int16x4_t quant_row1 = vld1_s16(quantptr + 1 * DCTSIZE + 4);
int16x4_t quant_row2 = vld1_s16(quantptr + 2 * DCTSIZE + 4);
int16x4_t quant_row3 = vld1_s16(quantptr + 3 * DCTSIZE + 4);
int16x4_t quant_row4 = vld1_s16(quantptr + 4 * DCTSIZE + 4);
int16x4_t quant_row5 = vld1_s16(quantptr + 5 * DCTSIZE + 4);
int16x4_t quant_row6 = vld1_s16(quantptr + 6 * DCTSIZE + 4);
int16x4_t quant_row7 = vld1_s16(quantptr + 7 * DCTSIZE + 4);
/* Even part: dequantize DCT coefficients. */
int16x4_t tmp0 = vget_high_s16(row0);
int16x4_t tmp1 = vmul_s16(vget_high_s16(row2), quant_row2);
int16x4_t tmp2 = vmul_s16(vget_high_s16(row4), quant_row4);
int16x4_t tmp3 = vmul_s16(vget_high_s16(row6), quant_row6);
int16x4_t tmp10 = vadd_s16(tmp0, tmp2); /* phase 3 */
int16x4_t tmp11 = vsub_s16(tmp0, tmp2);
int16x4_t tmp13 = vadd_s16(tmp1, tmp3); /* phases 5-3 */
int16x4_t tmp1_sub_tmp3 = vsub_s16(tmp1, tmp3);
int16x4_t tmp12 = vqdmulh_lane_s16(tmp1_sub_tmp3, consts, 1);
tmp12 = vadd_s16(tmp12, tmp1_sub_tmp3);
tmp12 = vsub_s16(tmp12, tmp13);
tmp0 = vadd_s16(tmp10, tmp13); /* phase 2 */
tmp3 = vsub_s16(tmp10, tmp13);
tmp1 = vadd_s16(tmp11, tmp12);
tmp2 = vsub_s16(tmp11, tmp12);
/* Odd part: dequantize DCT coefficients. */
int16x4_t tmp4 = vmul_s16(vget_high_s16(row1), quant_row1);
int16x4_t tmp5 = vmul_s16(vget_high_s16(row3), quant_row3);
int16x4_t tmp6 = vmul_s16(vget_high_s16(row5), quant_row5);
int16x4_t tmp7 = vmul_s16(vget_high_s16(row7), quant_row7);
int16x4_t z13 = vadd_s16(tmp6, tmp5); /* phase 6 */
int16x4_t neg_z10 = vsub_s16(tmp5, tmp6);
int16x4_t z11 = vadd_s16(tmp4, tmp7);
int16x4_t z12 = vsub_s16(tmp4, tmp7);
tmp7 = vadd_s16(z11, z13); /* phase 5 */
int16x4_t z11_sub_z13 = vsub_s16(z11, z13);
tmp11 = vqdmulh_lane_s16(z11_sub_z13, consts, 1);
tmp11 = vadd_s16(tmp11, z11_sub_z13);
int16x4_t z10_add_z12 = vsub_s16(z12, neg_z10);
int16x4_t z5 = vqdmulh_lane_s16(z10_add_z12, consts, 2);
z5 = vadd_s16(z5, z10_add_z12);
tmp10 = vqdmulh_lane_s16(z12, consts, 0);
tmp10 = vadd_s16(tmp10, z12);
tmp10 = vsub_s16(tmp10, z5);
tmp12 = vqdmulh_lane_s16(neg_z10, consts, 3);
tmp12 = vadd_s16(tmp12, vadd_s16(neg_z10, neg_z10));
tmp12 = vadd_s16(tmp12, z5);
tmp6 = vsub_s16(tmp12, tmp7); /* phase 2 */
tmp5 = vsub_s16(tmp11, tmp6);
tmp4 = vadd_s16(tmp10, tmp5);
row0 = vcombine_s16(dcval, vadd_s16(tmp0, tmp7));
row7 = vcombine_s16(dcval, vsub_s16(tmp0, tmp7));
row1 = vcombine_s16(dcval, vadd_s16(tmp1, tmp6));
row6 = vcombine_s16(dcval, vsub_s16(tmp1, tmp6));
row2 = vcombine_s16(dcval, vadd_s16(tmp2, tmp5));
row5 = vcombine_s16(dcval, vsub_s16(tmp2, tmp5));
row4 = vcombine_s16(dcval, vadd_s16(tmp3, tmp4));
row3 = vcombine_s16(dcval, vsub_s16(tmp3, tmp4));
} else if (right_ac_bitmap == 0) {
/* AC coefficients are zero for columns 4, 5, 6, and 7.
* Use DC values for these columns.
*/
int16x4_t dcval = vget_high_s16(row0);
/* Commence regular fast IDCT computation for columns 0, 1, 2, and 3. */
/* Load quantization table. */
int16x4_t quant_row1 = vld1_s16(quantptr + 1 * DCTSIZE);
int16x4_t quant_row2 = vld1_s16(quantptr + 2 * DCTSIZE);
int16x4_t quant_row3 = vld1_s16(quantptr + 3 * DCTSIZE);
int16x4_t quant_row4 = vld1_s16(quantptr + 4 * DCTSIZE);
int16x4_t quant_row5 = vld1_s16(quantptr + 5 * DCTSIZE);
int16x4_t quant_row6 = vld1_s16(quantptr + 6 * DCTSIZE);
int16x4_t quant_row7 = vld1_s16(quantptr + 7 * DCTSIZE);
/* Even part: dequantize DCT coefficients. */
int16x4_t tmp0 = vget_low_s16(row0);
int16x4_t tmp1 = vmul_s16(vget_low_s16(row2), quant_row2);
int16x4_t tmp2 = vmul_s16(vget_low_s16(row4), quant_row4);
int16x4_t tmp3 = vmul_s16(vget_low_s16(row6), quant_row6);
int16x4_t tmp10 = vadd_s16(tmp0, tmp2); /* phase 3 */
int16x4_t tmp11 = vsub_s16(tmp0, tmp2);
int16x4_t tmp13 = vadd_s16(tmp1, tmp3); /* phases 5-3 */
int16x4_t tmp1_sub_tmp3 = vsub_s16(tmp1, tmp3);
int16x4_t tmp12 = vqdmulh_lane_s16(tmp1_sub_tmp3, consts, 1);
tmp12 = vadd_s16(tmp12, tmp1_sub_tmp3);
tmp12 = vsub_s16(tmp12, tmp13);
tmp0 = vadd_s16(tmp10, tmp13); /* phase 2 */
tmp3 = vsub_s16(tmp10, tmp13);
tmp1 = vadd_s16(tmp11, tmp12);
tmp2 = vsub_s16(tmp11, tmp12);
/* Odd part: dequantize DCT coefficients. */
int16x4_t tmp4 = vmul_s16(vget_low_s16(row1), quant_row1);
int16x4_t tmp5 = vmul_s16(vget_low_s16(row3), quant_row3);
int16x4_t tmp6 = vmul_s16(vget_low_s16(row5), quant_row5);
int16x4_t tmp7 = vmul_s16(vget_low_s16(row7), quant_row7);
int16x4_t z13 = vadd_s16(tmp6, tmp5); /* phase 6 */
int16x4_t neg_z10 = vsub_s16(tmp5, tmp6);
int16x4_t z11 = vadd_s16(tmp4, tmp7);
int16x4_t z12 = vsub_s16(tmp4, tmp7);
tmp7 = vadd_s16(z11, z13); /* phase 5 */
int16x4_t z11_sub_z13 = vsub_s16(z11, z13);
tmp11 = vqdmulh_lane_s16(z11_sub_z13, consts, 1);
tmp11 = vadd_s16(tmp11, z11_sub_z13);
int16x4_t z10_add_z12 = vsub_s16(z12, neg_z10);
int16x4_t z5 = vqdmulh_lane_s16(z10_add_z12, consts, 2);
z5 = vadd_s16(z5, z10_add_z12);
tmp10 = vqdmulh_lane_s16(z12, consts, 0);
tmp10 = vadd_s16(tmp10, z12);
tmp10 = vsub_s16(tmp10, z5);
tmp12 = vqdmulh_lane_s16(neg_z10, consts, 3);
tmp12 = vadd_s16(tmp12, vadd_s16(neg_z10, neg_z10));
tmp12 = vadd_s16(tmp12, z5);
tmp6 = vsub_s16(tmp12, tmp7); /* phase 2 */
tmp5 = vsub_s16(tmp11, tmp6);
tmp4 = vadd_s16(tmp10, tmp5);
row0 = vcombine_s16(vadd_s16(tmp0, tmp7), dcval);
row7 = vcombine_s16(vsub_s16(tmp0, tmp7), dcval);
row1 = vcombine_s16(vadd_s16(tmp1, tmp6), dcval);
row6 = vcombine_s16(vsub_s16(tmp1, tmp6), dcval);
row2 = vcombine_s16(vadd_s16(tmp2, tmp5), dcval);
row5 = vcombine_s16(vsub_s16(tmp2, tmp5), dcval);
row4 = vcombine_s16(vadd_s16(tmp3, tmp4), dcval);
row3 = vcombine_s16(vsub_s16(tmp3, tmp4), dcval);
} else {
/* Some AC coefficients are non-zero; full IDCT calculation required. */
/* Load quantization table. */
int16x8_t quant_row1 = vld1q_s16(quantptr + 1 * DCTSIZE);
int16x8_t quant_row2 = vld1q_s16(quantptr + 2 * DCTSIZE);
int16x8_t quant_row3 = vld1q_s16(quantptr + 3 * DCTSIZE);
int16x8_t quant_row4 = vld1q_s16(quantptr + 4 * DCTSIZE);
int16x8_t quant_row5 = vld1q_s16(quantptr + 5 * DCTSIZE);
int16x8_t quant_row6 = vld1q_s16(quantptr + 6 * DCTSIZE);
int16x8_t quant_row7 = vld1q_s16(quantptr + 7 * DCTSIZE);
/* Even part: dequantize DCT coefficients. */
int16x8_t tmp0 = row0;
int16x8_t tmp1 = vmulq_s16(row2, quant_row2);
int16x8_t tmp2 = vmulq_s16(row4, quant_row4);
int16x8_t tmp3 = vmulq_s16(row6, quant_row6);
int16x8_t tmp10 = vaddq_s16(tmp0, tmp2); /* phase 3 */
int16x8_t tmp11 = vsubq_s16(tmp0, tmp2);
int16x8_t tmp13 = vaddq_s16(tmp1, tmp3); /* phases 5-3 */
int16x8_t tmp1_sub_tmp3 = vsubq_s16(tmp1, tmp3);
int16x8_t tmp12 = vqdmulhq_lane_s16(tmp1_sub_tmp3, consts, 1);
tmp12 = vaddq_s16(tmp12, tmp1_sub_tmp3);
tmp12 = vsubq_s16(tmp12, tmp13);
tmp0 = vaddq_s16(tmp10, tmp13); /* phase 2 */
tmp3 = vsubq_s16(tmp10, tmp13);
tmp1 = vaddq_s16(tmp11, tmp12);
tmp2 = vsubq_s16(tmp11, tmp12);
/* Odd part: dequantize DCT coefficients. */
int16x8_t tmp4 = vmulq_s16(row1, quant_row1);
int16x8_t tmp5 = vmulq_s16(row3, quant_row3);
int16x8_t tmp6 = vmulq_s16(row5, quant_row5);
int16x8_t tmp7 = vmulq_s16(row7, quant_row7);
int16x8_t z13 = vaddq_s16(tmp6, tmp5); /* phase 6 */
int16x8_t neg_z10 = vsubq_s16(tmp5, tmp6);
int16x8_t z11 = vaddq_s16(tmp4, tmp7);
int16x8_t z12 = vsubq_s16(tmp4, tmp7);
tmp7 = vaddq_s16(z11, z13); /* phase 5 */
int16x8_t z11_sub_z13 = vsubq_s16(z11, z13);
tmp11 = vqdmulhq_lane_s16(z11_sub_z13, consts, 1);
tmp11 = vaddq_s16(tmp11, z11_sub_z13);
int16x8_t z10_add_z12 = vsubq_s16(z12, neg_z10);
int16x8_t z5 = vqdmulhq_lane_s16(z10_add_z12, consts, 2);
z5 = vaddq_s16(z5, z10_add_z12);
tmp10 = vqdmulhq_lane_s16(z12, consts, 0);
tmp10 = vaddq_s16(tmp10, z12);
tmp10 = vsubq_s16(tmp10, z5);
tmp12 = vqdmulhq_lane_s16(neg_z10, consts, 3);
tmp12 = vaddq_s16(tmp12, vaddq_s16(neg_z10, neg_z10));
tmp12 = vaddq_s16(tmp12, z5);
tmp6 = vsubq_s16(tmp12, tmp7); /* phase 2 */
tmp5 = vsubq_s16(tmp11, tmp6);
tmp4 = vaddq_s16(tmp10, tmp5);
row0 = vaddq_s16(tmp0, tmp7);
row7 = vsubq_s16(tmp0, tmp7);
row1 = vaddq_s16(tmp1, tmp6);
row6 = vsubq_s16(tmp1, tmp6);
row2 = vaddq_s16(tmp2, tmp5);
row5 = vsubq_s16(tmp2, tmp5);
row4 = vaddq_s16(tmp3, tmp4);
row3 = vsubq_s16(tmp3, tmp4);
}
/* Transpose rows to work on columns in pass 2. */
int16x8x2_t rows_01 = vtrnq_s16(row0, row1);
int16x8x2_t rows_23 = vtrnq_s16(row2, row3);
int16x8x2_t rows_45 = vtrnq_s16(row4, row5);
int16x8x2_t rows_67 = vtrnq_s16(row6, row7);
int32x4x2_t rows_0145_l = vtrnq_s32(vreinterpretq_s32_s16(rows_01.val[0]),
vreinterpretq_s32_s16(rows_45.val[0]));
int32x4x2_t rows_0145_h = vtrnq_s32(vreinterpretq_s32_s16(rows_01.val[1]),
vreinterpretq_s32_s16(rows_45.val[1]));
int32x4x2_t rows_2367_l = vtrnq_s32(vreinterpretq_s32_s16(rows_23.val[0]),
vreinterpretq_s32_s16(rows_67.val[0]));
int32x4x2_t rows_2367_h = vtrnq_s32(vreinterpretq_s32_s16(rows_23.val[1]),
vreinterpretq_s32_s16(rows_67.val[1]));
int32x4x2_t cols_04 = vzipq_s32(rows_0145_l.val[0], rows_2367_l.val[0]);
int32x4x2_t cols_15 = vzipq_s32(rows_0145_h.val[0], rows_2367_h.val[0]);
int32x4x2_t cols_26 = vzipq_s32(rows_0145_l.val[1], rows_2367_l.val[1]);
int32x4x2_t cols_37 = vzipq_s32(rows_0145_h.val[1], rows_2367_h.val[1]);
int16x8_t col0 = vreinterpretq_s16_s32(cols_04.val[0]);
int16x8_t col1 = vreinterpretq_s16_s32(cols_15.val[0]);
int16x8_t col2 = vreinterpretq_s16_s32(cols_26.val[0]);
int16x8_t col3 = vreinterpretq_s16_s32(cols_37.val[0]);
int16x8_t col4 = vreinterpretq_s16_s32(cols_04.val[1]);
int16x8_t col5 = vreinterpretq_s16_s32(cols_15.val[1]);
int16x8_t col6 = vreinterpretq_s16_s32(cols_26.val[1]);
int16x8_t col7 = vreinterpretq_s16_s32(cols_37.val[1]);
/* 1-D IDCT, pass 2 */
/* Even part */
int16x8_t tmp10 = vaddq_s16(col0, col4);
int16x8_t tmp11 = vsubq_s16(col0, col4);
int16x8_t tmp13 = vaddq_s16(col2, col6);
int16x8_t col2_sub_col6 = vsubq_s16(col2, col6);
int16x8_t tmp12 = vqdmulhq_lane_s16(col2_sub_col6, consts, 1);
tmp12 = vaddq_s16(tmp12, col2_sub_col6);
tmp12 = vsubq_s16(tmp12, tmp13);
int16x8_t tmp0 = vaddq_s16(tmp10, tmp13);
int16x8_t tmp3 = vsubq_s16(tmp10, tmp13);
int16x8_t tmp1 = vaddq_s16(tmp11, tmp12);
int16x8_t tmp2 = vsubq_s16(tmp11, tmp12);
/* Odd part */
int16x8_t z13 = vaddq_s16(col5, col3);
int16x8_t neg_z10 = vsubq_s16(col3, col5);
int16x8_t z11 = vaddq_s16(col1, col7);
int16x8_t z12 = vsubq_s16(col1, col7);
int16x8_t tmp7 = vaddq_s16(z11, z13); /* phase 5 */
int16x8_t z11_sub_z13 = vsubq_s16(z11, z13);
tmp11 = vqdmulhq_lane_s16(z11_sub_z13, consts, 1);
tmp11 = vaddq_s16(tmp11, z11_sub_z13);
int16x8_t z10_add_z12 = vsubq_s16(z12, neg_z10);
int16x8_t z5 = vqdmulhq_lane_s16(z10_add_z12, consts, 2);
z5 = vaddq_s16(z5, z10_add_z12);
tmp10 = vqdmulhq_lane_s16(z12, consts, 0);
tmp10 = vaddq_s16(tmp10, z12);
tmp10 = vsubq_s16(tmp10, z5);
tmp12 = vqdmulhq_lane_s16(neg_z10, consts, 3);
tmp12 = vaddq_s16(tmp12, vaddq_s16(neg_z10, neg_z10));
tmp12 = vaddq_s16(tmp12, z5);
int16x8_t tmp6 = vsubq_s16(tmp12, tmp7); /* phase 2 */
int16x8_t tmp5 = vsubq_s16(tmp11, tmp6);
int16x8_t tmp4 = vaddq_s16(tmp10, tmp5);
col0 = vaddq_s16(tmp0, tmp7);
col7 = vsubq_s16(tmp0, tmp7);
col1 = vaddq_s16(tmp1, tmp6);
col6 = vsubq_s16(tmp1, tmp6);
col2 = vaddq_s16(tmp2, tmp5);
col5 = vsubq_s16(tmp2, tmp5);
col4 = vaddq_s16(tmp3, tmp4);
col3 = vsubq_s16(tmp3, tmp4);
/* Scale down by a factor of 8, narrowing to 8-bit. */
int8x16_t cols_01_s8 = vcombine_s8(vqshrn_n_s16(col0, PASS1_BITS + 3),
vqshrn_n_s16(col1, PASS1_BITS + 3));
int8x16_t cols_45_s8 = vcombine_s8(vqshrn_n_s16(col4, PASS1_BITS + 3),
vqshrn_n_s16(col5, PASS1_BITS + 3));
int8x16_t cols_23_s8 = vcombine_s8(vqshrn_n_s16(col2, PASS1_BITS + 3),
vqshrn_n_s16(col3, PASS1_BITS + 3));
int8x16_t cols_67_s8 = vcombine_s8(vqshrn_n_s16(col6, PASS1_BITS + 3),
vqshrn_n_s16(col7, PASS1_BITS + 3));
/* Clamp to range [0-255]. */
uint8x16_t cols_01 =
vreinterpretq_u8_s8
(vaddq_s8(cols_01_s8, vreinterpretq_s8_u8(vdupq_n_u8(CENTERJSAMPLE))));
uint8x16_t cols_45 =
vreinterpretq_u8_s8
(vaddq_s8(cols_45_s8, vreinterpretq_s8_u8(vdupq_n_u8(CENTERJSAMPLE))));
uint8x16_t cols_23 =
vreinterpretq_u8_s8
(vaddq_s8(cols_23_s8, vreinterpretq_s8_u8(vdupq_n_u8(CENTERJSAMPLE))));
uint8x16_t cols_67 =
vreinterpretq_u8_s8
(vaddq_s8(cols_67_s8, vreinterpretq_s8_u8(vdupq_n_u8(CENTERJSAMPLE))));
/* Transpose block to prepare for store. */
uint32x4x2_t cols_0415 = vzipq_u32(vreinterpretq_u32_u8(cols_01),
vreinterpretq_u32_u8(cols_45));
uint32x4x2_t cols_2637 = vzipq_u32(vreinterpretq_u32_u8(cols_23),
vreinterpretq_u32_u8(cols_67));
uint8x16x2_t cols_0145 = vtrnq_u8(vreinterpretq_u8_u32(cols_0415.val[0]),
vreinterpretq_u8_u32(cols_0415.val[1]));
uint8x16x2_t cols_2367 = vtrnq_u8(vreinterpretq_u8_u32(cols_2637.val[0]),
vreinterpretq_u8_u32(cols_2637.val[1]));
uint16x8x2_t rows_0426 = vtrnq_u16(vreinterpretq_u16_u8(cols_0145.val[0]),
vreinterpretq_u16_u8(cols_2367.val[0]));
uint16x8x2_t rows_1537 = vtrnq_u16(vreinterpretq_u16_u8(cols_0145.val[1]),
vreinterpretq_u16_u8(cols_2367.val[1]));
uint8x16_t rows_04 = vreinterpretq_u8_u16(rows_0426.val[0]);
uint8x16_t rows_15 = vreinterpretq_u8_u16(rows_1537.val[0]);
uint8x16_t rows_26 = vreinterpretq_u8_u16(rows_0426.val[1]);
uint8x16_t rows_37 = vreinterpretq_u8_u16(rows_1537.val[1]);
JSAMPROW outptr0 = output_buf[0] + output_col;
JSAMPROW outptr1 = output_buf[1] + output_col;
JSAMPROW outptr2 = output_buf[2] + output_col;
JSAMPROW outptr3 = output_buf[3] + output_col;
JSAMPROW outptr4 = output_buf[4] + output_col;
JSAMPROW outptr5 = output_buf[5] + output_col;
JSAMPROW outptr6 = output_buf[6] + output_col;
JSAMPROW outptr7 = output_buf[7] + output_col;
/* Store DCT block to memory. */
vst1q_lane_u64((uint64_t *)outptr0, vreinterpretq_u64_u8(rows_04), 0);
vst1q_lane_u64((uint64_t *)outptr1, vreinterpretq_u64_u8(rows_15), 0);
vst1q_lane_u64((uint64_t *)outptr2, vreinterpretq_u64_u8(rows_26), 0);
vst1q_lane_u64((uint64_t *)outptr3, vreinterpretq_u64_u8(rows_37), 0);
vst1q_lane_u64((uint64_t *)outptr4, vreinterpretq_u64_u8(rows_04), 1);
vst1q_lane_u64((uint64_t *)outptr5, vreinterpretq_u64_u8(rows_15), 1);
vst1q_lane_u64((uint64_t *)outptr6, vreinterpretq_u64_u8(rows_26), 1);
vst1q_lane_u64((uint64_t *)outptr7, vreinterpretq_u64_u8(rows_37), 1);
}