blob: 185591cb55bbe5765a815eef699063e79a04bb9c [file] [log] [blame]
/*
* Copyright 2014 The LibYuv Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "libyuv/row.h"
#include "libyuv/scale.h"
#include "libyuv/scale_row.h"
#ifdef __cplusplus
namespace libyuv {
extern "C" {
#endif
// This module is for GCC Neon armv8 64 bit.
#if !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
// Read 32x1 throw away even pixels, and write 16x1.
void ScaleRowDown2_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load even pixels into v0, odd into v1
"ld2 {v0.16b,v1.16b}, [%0], #32 \n"
"subs %w2, %w2, #16 \n" // 16 processed per loop
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st1 {v1.16b}, [%1], #16 \n" // store odd pixels
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst), // %1
"+r"(dst_width) // %2
:
: "v0", "v1" // Clobber List
);
}
// Read 32x1 average down and write 16x1.
void ScaleRowDown2Linear_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load even pixels into v0, odd into v1
"ld2 {v0.16b,v1.16b}, [%0], #32 \n"
"subs %w2, %w2, #16 \n" // 16 processed per loop
"urhadd v0.16b, v0.16b, v1.16b \n" // rounding half add
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st1 {v0.16b}, [%1], #16 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst), // %1
"+r"(dst_width) // %2
:
: "v0", "v1" // Clobber List
);
}
// Read 32x2 average down and write 16x1.
void ScaleRowDown2Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
asm volatile(
// change the stride to row 2 pointer
"add %1, %1, %0 \n"
"1: \n"
"ld1 {v0.16b, v1.16b}, [%0], #32 \n" // load row 1 and post inc
"ld1 {v2.16b, v3.16b}, [%1], #32 \n" // load row 2 and post inc
"subs %w3, %w3, #16 \n" // 16 processed per loop
"uaddlp v0.8h, v0.16b \n" // row 1 add adjacent
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uaddlp v1.8h, v1.16b \n"
"prfm pldl1keep, [%1, 448] \n"
"uadalp v0.8h, v2.16b \n" // += row 2 add adjacent
"uadalp v1.8h, v3.16b \n"
"rshrn v0.8b, v0.8h, #2 \n" // round and pack
"rshrn2 v0.16b, v1.8h, #2 \n"
"st1 {v0.16b}, [%2], #16 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src_stride), // %1
"+r"(dst), // %2
"+r"(dst_width) // %3
:
: "v0", "v1", "v2", "v3" // Clobber List
);
}
void ScaleRowDown4_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n" // src line 0
"subs %w2, %w2, #8 \n" // 8 processed per loop
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st1 {v2.8b}, [%1], #8 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(dst_width) // %2
:
: "v0", "v1", "v2", "v3", "memory", "cc");
}
void ScaleRowDown4Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
const uint8_t* src_ptr1 = src_ptr + src_stride;
const uint8_t* src_ptr2 = src_ptr + src_stride * 2;
const uint8_t* src_ptr3 = src_ptr + src_stride * 3;
asm volatile(
"1: \n"
"ld1 {v0.16b}, [%0], #16 \n" // load up 16x4
"ld1 {v1.16b}, [%2], #16 \n"
"ld1 {v2.16b}, [%3], #16 \n"
"ld1 {v3.16b}, [%4], #16 \n"
"subs %w5, %w5, #4 \n"
"uaddlp v0.8h, v0.16b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uadalp v0.8h, v1.16b \n"
"prfm pldl1keep, [%2, 448] \n"
"uadalp v0.8h, v2.16b \n"
"prfm pldl1keep, [%3, 448] \n"
"uadalp v0.8h, v3.16b \n"
"prfm pldl1keep, [%4, 448] \n"
"addp v0.8h, v0.8h, v0.8h \n"
"rshrn v0.8b, v0.8h, #4 \n" // divide by 16 w/rounding
"st1 {v0.s}[0], [%1], #4 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(src_ptr1), // %2
"+r"(src_ptr2), // %3
"+r"(src_ptr3), // %4
"+r"(dst_width) // %5
:
: "v0", "v1", "v2", "v3", "memory", "cc");
}
// Down scale from 4 to 3 pixels. Use the neon multilane read/write
// to load up the every 4th pixel into a 4 different registers.
// Point samples 32 pixels to 24 pixels.
void ScaleRowDown34_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n" // src line 0
"subs %w2, %w2, #24 \n"
"orr v2.16b, v3.16b, v3.16b \n" // order v0,v1,v2
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st3 {v0.8b,v1.8b,v2.8b}, [%1], #24 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(dst_width) // %2
:
: "v0", "v1", "v2", "v3", "memory", "cc");
}
void ScaleRowDown34_0_Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
asm volatile(
"movi v20.8b, #3 \n"
"add %3, %3, %0 \n"
"1: \n"
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n" // src line 0
"ld4 {v4.8b,v5.8b,v6.8b,v7.8b}, [%3], #32 \n" // src line 1
"subs %w2, %w2, #24 \n"
// filter src line 0 with src line 1
// expand chars to shorts to allow for room
// when adding lines together
"ushll v16.8h, v4.8b, #0 \n"
"ushll v17.8h, v5.8b, #0 \n"
"ushll v18.8h, v6.8b, #0 \n"
"ushll v19.8h, v7.8b, #0 \n"
// 3 * line_0 + line_1
"umlal v16.8h, v0.8b, v20.8b \n"
"umlal v17.8h, v1.8b, v20.8b \n"
"umlal v18.8h, v2.8b, v20.8b \n"
"umlal v19.8h, v3.8b, v20.8b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
// (3 * line_0 + line_1) >> 2
"uqrshrn v0.8b, v16.8h, #2 \n"
"uqrshrn v1.8b, v17.8h, #2 \n"
"uqrshrn v2.8b, v18.8h, #2 \n"
"uqrshrn v3.8b, v19.8h, #2 \n"
"prfm pldl1keep, [%3, 448] \n"
// a0 = (src[0] * 3 + s[1] * 1) >> 2
"ushll v16.8h, v1.8b, #0 \n"
"umlal v16.8h, v0.8b, v20.8b \n"
"uqrshrn v0.8b, v16.8h, #2 \n"
// a1 = (src[1] * 1 + s[2] * 1) >> 1
"urhadd v1.8b, v1.8b, v2.8b \n"
// a2 = (src[2] * 1 + s[3] * 3) >> 2
"ushll v16.8h, v2.8b, #0 \n"
"umlal v16.8h, v3.8b, v20.8b \n"
"uqrshrn v2.8b, v16.8h, #2 \n"
"st3 {v0.8b,v1.8b,v2.8b}, [%1], #24 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(dst_width), // %2
"+r"(src_stride) // %3
:
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16", "v17", "v18",
"v19", "v20", "memory", "cc");
}
void ScaleRowDown34_1_Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
asm volatile(
"movi v20.8b, #3 \n"
"add %3, %3, %0 \n"
"1: \n"
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n" // src line 0
"ld4 {v4.8b,v5.8b,v6.8b,v7.8b}, [%3], #32 \n" // src line 1
"subs %w2, %w2, #24 \n"
// average src line 0 with src line 1
"urhadd v0.8b, v0.8b, v4.8b \n"
"urhadd v1.8b, v1.8b, v5.8b \n"
"urhadd v2.8b, v2.8b, v6.8b \n"
"urhadd v3.8b, v3.8b, v7.8b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
// a0 = (src[0] * 3 + s[1] * 1) >> 2
"ushll v4.8h, v1.8b, #0 \n"
"umlal v4.8h, v0.8b, v20.8b \n"
"uqrshrn v0.8b, v4.8h, #2 \n"
"prfm pldl1keep, [%3, 448] \n"
// a1 = (src[1] * 1 + s[2] * 1) >> 1
"urhadd v1.8b, v1.8b, v2.8b \n"
// a2 = (src[2] * 1 + s[3] * 3) >> 2
"ushll v4.8h, v2.8b, #0 \n"
"umlal v4.8h, v3.8b, v20.8b \n"
"uqrshrn v2.8b, v4.8h, #2 \n"
"st3 {v0.8b,v1.8b,v2.8b}, [%1], #24 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(dst_width), // %2
"+r"(src_stride) // %3
:
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v20", "memory", "cc");
}
static const uvec8 kShuf38 = {0, 3, 6, 8, 11, 14, 16, 19,
22, 24, 27, 30, 0, 0, 0, 0};
static const uvec8 kShuf38_2 = {0, 16, 32, 2, 18, 33, 4, 20,
34, 6, 22, 35, 0, 0, 0, 0};
static const vec16 kMult38_Div6 = {65536 / 12, 65536 / 12, 65536 / 12,
65536 / 12, 65536 / 12, 65536 / 12,
65536 / 12, 65536 / 12};
static const vec16 kMult38_Div9 = {65536 / 18, 65536 / 18, 65536 / 18,
65536 / 18, 65536 / 18, 65536 / 18,
65536 / 18, 65536 / 18};
// 32 -> 12
void ScaleRowDown38_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
(void)src_stride;
asm volatile(
"ld1 {v3.16b}, [%3] \n"
"1: \n"
"ld1 {v0.16b,v1.16b}, [%0], #32 \n"
"subs %w2, %w2, #12 \n"
"tbl v2.16b, {v0.16b,v1.16b}, v3.16b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st1 {v2.8b}, [%1], #8 \n"
"st1 {v2.s}[2], [%1], #4 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(dst_width) // %2
: "r"(&kShuf38) // %3
: "v0", "v1", "v2", "v3", "memory", "cc");
}
// 32x3 -> 12x1
void OMITFP ScaleRowDown38_3_Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
const uint8_t* src_ptr1 = src_ptr + src_stride * 2;
ptrdiff_t tmp_src_stride = src_stride;
asm volatile(
"ld1 {v29.8h}, [%5] \n"
"ld1 {v30.16b}, [%6] \n"
"ld1 {v31.8h}, [%7] \n"
"add %2, %2, %0 \n"
"1: \n"
// 00 40 01 41 02 42 03 43
// 10 50 11 51 12 52 13 53
// 20 60 21 61 22 62 23 63
// 30 70 31 71 32 72 33 73
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"
"ld4 {v4.8b,v5.8b,v6.8b,v7.8b}, [%2], #32 \n"
"ld4 {v16.8b,v17.8b,v18.8b,v19.8b}, [%3], #32 \n"
"subs %w4, %w4, #12 \n"
// Shuffle the input data around to get align the data
// so adjacent data can be added. 0,1 - 2,3 - 4,5 - 6,7
// 00 10 01 11 02 12 03 13
// 40 50 41 51 42 52 43 53
"trn1 v20.8b, v0.8b, v1.8b \n"
"trn2 v21.8b, v0.8b, v1.8b \n"
"trn1 v22.8b, v4.8b, v5.8b \n"
"trn2 v23.8b, v4.8b, v5.8b \n"
"trn1 v24.8b, v16.8b, v17.8b \n"
"trn2 v25.8b, v16.8b, v17.8b \n"
// 20 30 21 31 22 32 23 33
// 60 70 61 71 62 72 63 73
"trn1 v0.8b, v2.8b, v3.8b \n"
"trn2 v1.8b, v2.8b, v3.8b \n"
"trn1 v4.8b, v6.8b, v7.8b \n"
"trn2 v5.8b, v6.8b, v7.8b \n"
"trn1 v16.8b, v18.8b, v19.8b \n"
"trn2 v17.8b, v18.8b, v19.8b \n"
// 00+10 01+11 02+12 03+13
// 40+50 41+51 42+52 43+53
"uaddlp v20.4h, v20.8b \n"
"uaddlp v21.4h, v21.8b \n"
"uaddlp v22.4h, v22.8b \n"
"uaddlp v23.4h, v23.8b \n"
"uaddlp v24.4h, v24.8b \n"
"uaddlp v25.4h, v25.8b \n"
// 60+70 61+71 62+72 63+73
"uaddlp v1.4h, v1.8b \n"
"uaddlp v5.4h, v5.8b \n"
"uaddlp v17.4h, v17.8b \n"
// combine source lines
"add v20.4h, v20.4h, v22.4h \n"
"add v21.4h, v21.4h, v23.4h \n"
"add v20.4h, v20.4h, v24.4h \n"
"add v21.4h, v21.4h, v25.4h \n"
"add v2.4h, v1.4h, v5.4h \n"
"add v2.4h, v2.4h, v17.4h \n"
// dst_ptr[3] = (s[6 + st * 0] + s[7 + st * 0]
// + s[6 + st * 1] + s[7 + st * 1]
// + s[6 + st * 2] + s[7 + st * 2]) / 6
"sqrdmulh v2.8h, v2.8h, v29.8h \n"
"xtn v2.8b, v2.8h \n"
// Shuffle 2,3 reg around so that 2 can be added to the
// 0,1 reg and 3 can be added to the 4,5 reg. This
// requires expanding from u8 to u16 as the 0,1 and 4,5
// registers are already expanded. Then do transposes
// to get aligned.
// xx 20 xx 30 xx 21 xx 31 xx 22 xx 32 xx 23 xx 33
"ushll v16.8h, v16.8b, #0 \n"
"uaddl v0.8h, v0.8b, v4.8b \n"
// combine source lines
"add v0.8h, v0.8h, v16.8h \n"
// xx 20 xx 21 xx 22 xx 23
// xx 30 xx 31 xx 32 xx 33
"trn1 v1.8h, v0.8h, v0.8h \n"
"trn2 v4.8h, v0.8h, v0.8h \n"
"xtn v0.4h, v1.4s \n"
"xtn v4.4h, v4.4s \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
// 0+1+2, 3+4+5
"add v20.8h, v20.8h, v0.8h \n"
"add v21.8h, v21.8h, v4.8h \n"
"prfm pldl1keep, [%2, 448] \n"
// Need to divide, but can't downshift as the the value
// isn't a power of 2. So multiply by 65536 / n
// and take the upper 16 bits.
"sqrdmulh v0.8h, v20.8h, v31.8h \n"
"sqrdmulh v1.8h, v21.8h, v31.8h \n"
"prfm pldl1keep, [%3, 448] \n"
// Align for table lookup, vtbl requires registers to be adjacent
"tbl v3.16b, {v0.16b, v1.16b, v2.16b}, v30.16b \n"
"st1 {v3.8b}, [%1], #8 \n"
"st1 {v3.s}[2], [%1], #4 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(tmp_src_stride), // %2
"+r"(src_ptr1), // %3
"+r"(dst_width) // %4
: "r"(&kMult38_Div6), // %5
"r"(&kShuf38_2), // %6
"r"(&kMult38_Div9) // %7
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16", "v17", "v18",
"v19", "v20", "v21", "v22", "v23", "v24", "v25", "v29", "v30", "v31",
"memory", "cc");
}
// 32x2 -> 12x1
void ScaleRowDown38_2_Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst_ptr,
int dst_width) {
// TODO(fbarchard): use src_stride directly for clang 3.5+.
ptrdiff_t tmp_src_stride = src_stride;
asm volatile(
"ld1 {v30.8h}, [%4] \n"
"ld1 {v31.16b}, [%5] \n"
"add %2, %2, %0 \n"
"1: \n"
// 00 40 01 41 02 42 03 43
// 10 50 11 51 12 52 13 53
// 20 60 21 61 22 62 23 63
// 30 70 31 71 32 72 33 73
"ld4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%0], #32 \n"
"ld4 {v4.8b,v5.8b,v6.8b,v7.8b}, [%2], #32 \n"
"subs %w3, %w3, #12 \n"
// Shuffle the input data around to get align the data
// so adjacent data can be added. 0,1 - 2,3 - 4,5 - 6,7
// 00 10 01 11 02 12 03 13
// 40 50 41 51 42 52 43 53
"trn1 v16.8b, v0.8b, v1.8b \n"
"trn2 v17.8b, v0.8b, v1.8b \n"
"trn1 v18.8b, v4.8b, v5.8b \n"
"trn2 v19.8b, v4.8b, v5.8b \n"
// 20 30 21 31 22 32 23 33
// 60 70 61 71 62 72 63 73
"trn1 v0.8b, v2.8b, v3.8b \n"
"trn2 v1.8b, v2.8b, v3.8b \n"
"trn1 v4.8b, v6.8b, v7.8b \n"
"trn2 v5.8b, v6.8b, v7.8b \n"
// 00+10 01+11 02+12 03+13
// 40+50 41+51 42+52 43+53
"uaddlp v16.4h, v16.8b \n"
"uaddlp v17.4h, v17.8b \n"
"uaddlp v18.4h, v18.8b \n"
"uaddlp v19.4h, v19.8b \n"
// 60+70 61+71 62+72 63+73
"uaddlp v1.4h, v1.8b \n"
"uaddlp v5.4h, v5.8b \n"
// combine source lines
"add v16.4h, v16.4h, v18.4h \n"
"add v17.4h, v17.4h, v19.4h \n"
"add v2.4h, v1.4h, v5.4h \n"
// dst_ptr[3] = (s[6] + s[7] + s[6+st] + s[7+st]) / 4
"uqrshrn v2.8b, v2.8h, #2 \n"
// Shuffle 2,3 reg around so that 2 can be added to the
// 0,1 reg and 3 can be added to the 4,5 reg. This
// requires expanding from u8 to u16 as the 0,1 and 4,5
// registers are already expanded. Then do transposes
// to get aligned.
// xx 20 xx 30 xx 21 xx 31 xx 22 xx 32 xx 23 xx 33
// combine source lines
"uaddl v0.8h, v0.8b, v4.8b \n"
// xx 20 xx 21 xx 22 xx 23
// xx 30 xx 31 xx 32 xx 33
"trn1 v1.8h, v0.8h, v0.8h \n"
"trn2 v4.8h, v0.8h, v0.8h \n"
"xtn v0.4h, v1.4s \n"
"xtn v4.4h, v4.4s \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
// 0+1+2, 3+4+5
"add v16.8h, v16.8h, v0.8h \n"
"add v17.8h, v17.8h, v4.8h \n"
"prfm pldl1keep, [%2, 448] \n"
// Need to divide, but can't downshift as the the value
// isn't a power of 2. So multiply by 65536 / n
// and take the upper 16 bits.
"sqrdmulh v0.8h, v16.8h, v30.8h \n"
"sqrdmulh v1.8h, v17.8h, v30.8h \n"
// Align for table lookup, vtbl requires registers to
// be adjacent
"tbl v3.16b, {v0.16b, v1.16b, v2.16b}, v31.16b \n"
"st1 {v3.8b}, [%1], #8 \n"
"st1 {v3.s}[2], [%1], #4 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(tmp_src_stride), // %2
"+r"(dst_width) // %3
: "r"(&kMult38_Div6), // %4
"r"(&kShuf38_2) // %5
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16", "v17", "v18",
"v19", "v30", "v31", "memory", "cc");
}
// Add a row of bytes to a row of shorts. Used for box filter.
// Reads 16 bytes and accumulates to 16 shorts at a time.
void ScaleAddRow_NEON(const uint8_t* src_ptr,
uint16_t* dst_ptr,
int src_width) {
asm volatile(
"1: \n"
"ld1 {v1.8h, v2.8h}, [%1] \n" // load accumulator
"ld1 {v0.16b}, [%0], #16 \n" // load 16 bytes
"uaddw2 v2.8h, v2.8h, v0.16b \n" // add
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uaddw v1.8h, v1.8h, v0.8b \n"
"st1 {v1.8h, v2.8h}, [%1], #32 \n" // store accumulator
"subs %w2, %w2, #16 \n" // 16 processed per loop
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst_ptr), // %1
"+r"(src_width) // %2
:
: "memory", "cc", "v0", "v1", "v2" // Clobber List
);
}
// TODO(Yang Zhang): Investigate less load instructions for
// the x/dx stepping
#define LOAD2_DATA8_LANE(n) \
"lsr %5, %3, #16 \n" \
"add %6, %1, %5 \n" \
"add %3, %3, %4 \n" \
"ld2 {v4.b, v5.b}[" #n "], [%6] \n"
// The NEON version mimics this formula (from row_common.cc):
// #define BLENDER(a, b, f) (uint8_t)((int)(a) +
// ((((int)((f)) * ((int)(b) - (int)(a))) + 0x8000) >> 16))
void ScaleFilterCols_NEON(uint8_t* dst_ptr,
const uint8_t* src_ptr,
int dst_width,
int x,
int dx) {
int dx_offset[4] = {0, 1, 2, 3};
int* tmp = dx_offset;
const uint8_t* src_tmp = src_ptr;
int64_t x64 = (int64_t)x; // NOLINT
int64_t dx64 = (int64_t)dx; // NOLINT
asm volatile (
"dup v0.4s, %w3 \n" // x
"dup v1.4s, %w4 \n" // dx
"ld1 {v2.4s}, [%5] \n" // 0 1 2 3
"shl v3.4s, v1.4s, #2 \n" // 4 * dx
"mul v1.4s, v1.4s, v2.4s \n"
// x , x + 1 * dx, x + 2 * dx, x + 3 * dx
"add v1.4s, v1.4s, v0.4s \n"
// x + 4 * dx, x + 5 * dx, x + 6 * dx, x + 7 * dx
"add v2.4s, v1.4s, v3.4s \n"
"shl v0.4s, v3.4s, #1 \n" // 8 * dx
"1: \n"
LOAD2_DATA8_LANE(0)
LOAD2_DATA8_LANE(1)
LOAD2_DATA8_LANE(2)
LOAD2_DATA8_LANE(3)
LOAD2_DATA8_LANE(4)
LOAD2_DATA8_LANE(5)
LOAD2_DATA8_LANE(6)
LOAD2_DATA8_LANE(7)
"mov v6.16b, v1.16b \n"
"mov v7.16b, v2.16b \n"
"uzp1 v6.8h, v6.8h, v7.8h \n"
"ushll v4.8h, v4.8b, #0 \n"
"ushll v5.8h, v5.8b, #0 \n"
"ssubl v16.4s, v5.4h, v4.4h \n"
"ssubl2 v17.4s, v5.8h, v4.8h \n"
"ushll v7.4s, v6.4h, #0 \n"
"ushll2 v6.4s, v6.8h, #0 \n"
"mul v16.4s, v16.4s, v7.4s \n"
"mul v17.4s, v17.4s, v6.4s \n"
"rshrn v6.4h, v16.4s, #16 \n"
"rshrn2 v6.8h, v17.4s, #16 \n"
"add v4.8h, v4.8h, v6.8h \n"
"xtn v4.8b, v4.8h \n"
"st1 {v4.8b}, [%0], #8 \n" // store pixels
"add v1.4s, v1.4s, v0.4s \n"
"add v2.4s, v2.4s, v0.4s \n"
"subs %w2, %w2, #8 \n" // 8 processed per loop
"b.gt 1b \n"
: "+r"(dst_ptr), // %0
"+r"(src_ptr), // %1
"+r"(dst_width), // %2
"+r"(x64), // %3
"+r"(dx64), // %4
"+r"(tmp), // %5
"+r"(src_tmp) // %6
:
: "memory", "cc", "v0", "v1", "v2", "v3",
"v4", "v5", "v6", "v7", "v16", "v17"
);
}
#undef LOAD2_DATA8_LANE
// 16x2 -> 16x1
void ScaleFilterRows_NEON(uint8_t* dst_ptr,
const uint8_t* src_ptr,
ptrdiff_t src_stride,
int dst_width,
int source_y_fraction) {
int y_fraction = 256 - source_y_fraction;
asm volatile(
"cmp %w4, #0 \n"
"b.eq 100f \n"
"add %2, %2, %1 \n"
"cmp %w4, #64 \n"
"b.eq 75f \n"
"cmp %w4, #128 \n"
"b.eq 50f \n"
"cmp %w4, #192 \n"
"b.eq 25f \n"
"dup v5.8b, %w4 \n"
"dup v4.8b, %w5 \n"
// General purpose row blend.
"1: \n"
"ld1 {v0.16b}, [%1], #16 \n"
"ld1 {v1.16b}, [%2], #16 \n"
"subs %w3, %w3, #16 \n"
"umull v6.8h, v0.8b, v4.8b \n"
"umull2 v7.8h, v0.16b, v4.16b \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"umlal v6.8h, v1.8b, v5.8b \n"
"umlal2 v7.8h, v1.16b, v5.16b \n"
"prfm pldl1keep, [%2, 448] \n"
"rshrn v0.8b, v6.8h, #8 \n"
"rshrn2 v0.16b, v7.8h, #8 \n"
"st1 {v0.16b}, [%0], #16 \n"
"b.gt 1b \n"
"b 99f \n"
// Blend 25 / 75.
"25: \n"
"ld1 {v0.16b}, [%1], #16 \n"
"ld1 {v1.16b}, [%2], #16 \n"
"subs %w3, %w3, #16 \n"
"urhadd v0.16b, v0.16b, v1.16b \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"urhadd v0.16b, v0.16b, v1.16b \n"
"prfm pldl1keep, [%2, 448] \n"
"st1 {v0.16b}, [%0], #16 \n"
"b.gt 25b \n"
"b 99f \n"
// Blend 50 / 50.
"50: \n"
"ld1 {v0.16b}, [%1], #16 \n"
"ld1 {v1.16b}, [%2], #16 \n"
"subs %w3, %w3, #16 \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"urhadd v0.16b, v0.16b, v1.16b \n"
"prfm pldl1keep, [%2, 448] \n"
"st1 {v0.16b}, [%0], #16 \n"
"b.gt 50b \n"
"b 99f \n"
// Blend 75 / 25.
"75: \n"
"ld1 {v1.16b}, [%1], #16 \n"
"ld1 {v0.16b}, [%2], #16 \n"
"subs %w3, %w3, #16 \n"
"urhadd v0.16b, v0.16b, v1.16b \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"urhadd v0.16b, v0.16b, v1.16b \n"
"prfm pldl1keep, [%2, 448] \n"
"st1 {v0.16b}, [%0], #16 \n"
"b.gt 75b \n"
"b 99f \n"
// Blend 100 / 0 - Copy row unchanged.
"100: \n"
"ld1 {v0.16b}, [%1], #16 \n"
"subs %w3, %w3, #16 \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"st1 {v0.16b}, [%0], #16 \n"
"b.gt 100b \n"
"99: \n"
"st1 {v0.b}[15], [%0] \n"
: "+r"(dst_ptr), // %0
"+r"(src_ptr), // %1
"+r"(src_stride), // %2
"+r"(dst_width), // %3
"+r"(source_y_fraction), // %4
"+r"(y_fraction) // %5
:
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "memory", "cc");
}
void ScaleARGBRowDown2_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load 16 ARGB pixels with even pixels into q0/q2, odd into q1/q3
"ld4 {v0.4s,v1.4s,v2.4s,v3.4s}, [%0], #64 \n"
"subs %w2, %w2, #8 \n" // 8 processed per loop
"mov v2.16b, v3.16b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st2 {v1.4s,v2.4s}, [%1], #32 \n" // store 8 odd pixels
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst), // %1
"+r"(dst_width) // %2
:
: "memory", "cc", "v0", "v1", "v2", "v3" // Clobber List
);
}
void ScaleARGBRowDown2Linear_NEON(const uint8_t* src_argb,
ptrdiff_t src_stride,
uint8_t* dst_argb,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load 16 ARGB pixels with even pixels into q0/q2, odd into q1/q3
"ld4 {v0.4s,v1.4s,v2.4s,v3.4s}, [%0], #64 \n"
"subs %w2, %w2, #8 \n" // 8 processed per loop
"urhadd v0.16b, v0.16b, v1.16b \n" // rounding half add
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"urhadd v1.16b, v2.16b, v3.16b \n"
"st2 {v0.4s,v1.4s}, [%1], #32 \n" // store 8 pixels
"b.gt 1b \n"
: "+r"(src_argb), // %0
"+r"(dst_argb), // %1
"+r"(dst_width) // %2
:
: "memory", "cc", "v0", "v1", "v2", "v3" // Clobber List
);
}
void ScaleARGBRowDown2Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
asm volatile(
// change the stride to row 2 pointer
"add %1, %1, %0 \n"
"1: \n"
"ld4 {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n" // load 16 ARGB
"subs %w3, %w3, #8 \n" // 8 processed per loop.
"uaddlp v0.8h, v0.16b \n" // B 16 bytes -> 8 shorts.
"uaddlp v1.8h, v1.16b \n" // G 16 bytes -> 8 shorts.
"uaddlp v2.8h, v2.16b \n" // R 16 bytes -> 8 shorts.
"uaddlp v3.8h, v3.16b \n" // A 16 bytes -> 8 shorts.
"ld4 {v16.16b,v17.16b,v18.16b,v19.16b}, [%1], #64 \n" // load 8
"uadalp v0.8h, v16.16b \n" // B 16 bytes -> 8 shorts.
"uadalp v1.8h, v17.16b \n" // G 16 bytes -> 8 shorts.
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uadalp v2.8h, v18.16b \n" // R 16 bytes -> 8 shorts.
"uadalp v3.8h, v19.16b \n" // A 16 bytes -> 8 shorts.
"prfm pldl1keep, [%1, 448] \n"
"rshrn v0.8b, v0.8h, #2 \n" // round and pack
"rshrn v1.8b, v1.8h, #2 \n"
"rshrn v2.8b, v2.8h, #2 \n"
"rshrn v3.8b, v3.8h, #2 \n"
"st4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%2], #32 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src_stride), // %1
"+r"(dst), // %2
"+r"(dst_width) // %3
:
: "memory", "cc", "v0", "v1", "v2", "v3", "v16", "v17", "v18", "v19");
}
// Reads 4 pixels at a time.
// Alignment requirement: src_argb 4 byte aligned.
void ScaleARGBRowDownEven_NEON(const uint8_t* src_argb,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_argb,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
"ld1 {v0.s}[0], [%0], %3 \n"
"ld1 {v0.s}[1], [%0], %3 \n"
"ld1 {v0.s}[2], [%0], %3 \n"
"ld1 {v0.s}[3], [%0], %3 \n"
"subs %w2, %w2, #4 \n" // 4 pixels per loop.
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"st1 {v0.16b}, [%1], #16 \n"
"b.gt 1b \n"
: "+r"(src_argb), // %0
"+r"(dst_argb), // %1
"+r"(dst_width) // %2
: "r"((int64_t)(src_stepx * 4)) // %3
: "memory", "cc", "v0");
}
// Reads 4 pixels at a time.
// Alignment requirement: src_argb 4 byte aligned.
// TODO(Yang Zhang): Might be worth another optimization pass in future.
// It could be upgraded to 8 pixels at a time to start with.
void ScaleARGBRowDownEvenBox_NEON(const uint8_t* src_argb,
ptrdiff_t src_stride,
int src_stepx,
uint8_t* dst_argb,
int dst_width) {
asm volatile(
"add %1, %1, %0 \n"
"1: \n"
"ld1 {v0.8b}, [%0], %4 \n" // Read 4 2x2 -> 2x1
"ld1 {v1.8b}, [%1], %4 \n"
"ld1 {v2.8b}, [%0], %4 \n"
"ld1 {v3.8b}, [%1], %4 \n"
"ld1 {v4.8b}, [%0], %4 \n"
"ld1 {v5.8b}, [%1], %4 \n"
"ld1 {v6.8b}, [%0], %4 \n"
"ld1 {v7.8b}, [%1], %4 \n"
"uaddl v0.8h, v0.8b, v1.8b \n"
"uaddl v2.8h, v2.8b, v3.8b \n"
"uaddl v4.8h, v4.8b, v5.8b \n"
"uaddl v6.8h, v6.8b, v7.8b \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"mov v16.d[1], v0.d[1] \n" // ab_cd -> ac_bd
"mov v0.d[1], v2.d[0] \n"
"mov v2.d[0], v16.d[1] \n"
"mov v16.d[1], v4.d[1] \n" // ef_gh -> eg_fh
"mov v4.d[1], v6.d[0] \n"
"mov v6.d[0], v16.d[1] \n"
"prfm pldl1keep, [%1, 448] \n"
"add v0.8h, v0.8h, v2.8h \n" // (a+b)_(c+d)
"add v4.8h, v4.8h, v6.8h \n" // (e+f)_(g+h)
"rshrn v0.8b, v0.8h, #2 \n" // first 2 pixels.
"rshrn2 v0.16b, v4.8h, #2 \n" // next 2 pixels.
"subs %w3, %w3, #4 \n" // 4 pixels per loop.
"st1 {v0.16b}, [%2], #16 \n"
"b.gt 1b \n"
: "+r"(src_argb), // %0
"+r"(src_stride), // %1
"+r"(dst_argb), // %2
"+r"(dst_width) // %3
: "r"((int64_t)(src_stepx * 4)) // %4
: "memory", "cc", "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16");
}
// TODO(Yang Zhang): Investigate less load instructions for
// the x/dx stepping
#define LOAD1_DATA32_LANE(vn, n) \
"lsr %5, %3, #16 \n" \
"add %6, %1, %5, lsl #2 \n" \
"add %3, %3, %4 \n" \
"ld1 {" #vn ".s}[" #n "], [%6] \n"
void ScaleARGBCols_NEON(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x,
int dx) {
const uint8_t* src_tmp = src_argb;
int64_t x64 = (int64_t)x; // NOLINT
int64_t dx64 = (int64_t)dx; // NOLINT
int64_t tmp64;
asm volatile(
"1: \n"
// clang-format off
LOAD1_DATA32_LANE(v0, 0)
LOAD1_DATA32_LANE(v0, 1)
LOAD1_DATA32_LANE(v0, 2)
LOAD1_DATA32_LANE(v0, 3)
LOAD1_DATA32_LANE(v1, 0)
LOAD1_DATA32_LANE(v1, 1)
LOAD1_DATA32_LANE(v1, 2)
LOAD1_DATA32_LANE(v1, 3)
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
// clang-format on
"st1 {v0.4s, v1.4s}, [%0], #32 \n" // store pixels
"subs %w2, %w2, #8 \n" // 8 processed per loop
"b.gt 1b \n"
: "+r"(dst_argb), // %0
"+r"(src_argb), // %1
"+r"(dst_width), // %2
"+r"(x64), // %3
"+r"(dx64), // %4
"=&r"(tmp64), // %5
"+r"(src_tmp) // %6
:
: "memory", "cc", "v0", "v1");
}
#undef LOAD1_DATA32_LANE
// TODO(Yang Zhang): Investigate less load instructions for
// the x/dx stepping
#define LOAD2_DATA32_LANE(vn1, vn2, n) \
"lsr %5, %3, #16 \n" \
"add %6, %1, %5, lsl #2 \n" \
"add %3, %3, %4 \n" \
"ld2 {" #vn1 ".s, " #vn2 ".s}[" #n "], [%6] \n"
void ScaleARGBFilterCols_NEON(uint8_t* dst_argb,
const uint8_t* src_argb,
int dst_width,
int x,
int dx) {
int dx_offset[4] = {0, 1, 2, 3};
int* tmp = dx_offset;
const uint8_t* src_tmp = src_argb;
int64_t x64 = (int64_t)x; // NOLINT
int64_t dx64 = (int64_t)dx; // NOLINT
asm volatile (
"dup v0.4s, %w3 \n" // x
"dup v1.4s, %w4 \n" // dx
"ld1 {v2.4s}, [%5] \n" // 0 1 2 3
"shl v6.4s, v1.4s, #2 \n" // 4 * dx
"mul v1.4s, v1.4s, v2.4s \n"
"movi v3.16b, #0x7f \n" // 0x7F
"movi v4.8h, #0x7f \n" // 0x7F
// x , x + 1 * dx, x + 2 * dx, x + 3 * dx
"add v5.4s, v1.4s, v0.4s \n"
"1: \n"
// d0, d1: a
// d2, d3: b
LOAD2_DATA32_LANE(v0, v1, 0)
LOAD2_DATA32_LANE(v0, v1, 1)
LOAD2_DATA32_LANE(v0, v1, 2)
LOAD2_DATA32_LANE(v0, v1, 3)
"shrn v2.4h, v5.4s, #9 \n"
"and v2.8b, v2.8b, v4.8b \n"
"dup v16.8b, v2.b[0] \n"
"dup v17.8b, v2.b[2] \n"
"dup v18.8b, v2.b[4] \n"
"dup v19.8b, v2.b[6] \n"
"ext v2.8b, v16.8b, v17.8b, #4 \n"
"ext v17.8b, v18.8b, v19.8b, #4 \n"
"ins v2.d[1], v17.d[0] \n" // f
"eor v7.16b, v2.16b, v3.16b \n" // 0x7f ^ f
"umull v16.8h, v0.8b, v7.8b \n"
"umull2 v17.8h, v0.16b, v7.16b \n"
"umull v18.8h, v1.8b, v2.8b \n"
"umull2 v19.8h, v1.16b, v2.16b \n"
"prfm pldl1keep, [%1, 448] \n" // prefetch 7 lines ahead
"add v16.8h, v16.8h, v18.8h \n"
"add v17.8h, v17.8h, v19.8h \n"
"shrn v0.8b, v16.8h, #7 \n"
"shrn2 v0.16b, v17.8h, #7 \n"
"st1 {v0.4s}, [%0], #16 \n" // store pixels
"add v5.4s, v5.4s, v6.4s \n"
"subs %w2, %w2, #4 \n" // 4 processed per loop
"b.gt 1b \n"
: "+r"(dst_argb), // %0
"+r"(src_argb), // %1
"+r"(dst_width), // %2
"+r"(x64), // %3
"+r"(dx64), // %4
"+r"(tmp), // %5
"+r"(src_tmp) // %6
:
: "memory", "cc", "v0", "v1", "v2", "v3", "v4", "v5",
"v6", "v7", "v16", "v17", "v18", "v19"
);
}
#undef LOAD2_DATA32_LANE
// Read 16x2 average down and write 8x1.
void ScaleRowDown2Box_16_NEON(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
asm volatile(
// change the stride to row 2 pointer
"add %1, %0, %1, lsl #1 \n" // ptr + stide * 2
"1: \n"
"ld1 {v0.8h, v1.8h}, [%0], #32 \n" // load row 1 and post inc
"ld1 {v2.8h, v3.8h}, [%1], #32 \n" // load row 2 and post inc
"subs %w3, %w3, #8 \n" // 8 processed per loop
"uaddlp v0.4s, v0.8h \n" // row 1 add adjacent
"uaddlp v1.4s, v1.8h \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uadalp v0.4s, v2.8h \n" // +row 2 add adjacent
"uadalp v1.4s, v3.8h \n"
"prfm pldl1keep, [%1, 448] \n"
"rshrn v0.4h, v0.4s, #2 \n" // round and pack
"rshrn2 v0.8h, v1.4s, #2 \n"
"st1 {v0.8h}, [%2], #16 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src_stride), // %1
"+r"(dst), // %2
"+r"(dst_width) // %3
:
: "v0", "v1", "v2", "v3" // Clobber List
);
}
// Read 8x2 upsample with filtering and write 16x1.
// Actually reads an extra pixel, so 9x2.
void ScaleRowUp2_16_NEON(const uint16_t* src_ptr,
ptrdiff_t src_stride,
uint16_t* dst,
int dst_width) {
asm volatile(
"add %1, %0, %1, lsl #1 \n" // ptr + stide * 2
"movi v0.8h, #9 \n" // constants
"movi v1.4s, #3 \n"
"1: \n"
"ld1 {v3.8h}, [%0], %4 \n" // TL read first 8
"ld1 {v4.8h}, [%0], %5 \n" // TR read 8 offset by 1
"ld1 {v5.8h}, [%1], %4 \n" // BL read 8 from next row
"ld1 {v6.8h}, [%1], %5 \n" // BR offset by 1
"subs %w3, %w3, #16 \n" // 16 dst pixels per loop
"umull v16.4s, v3.4h, v0.4h \n"
"umull2 v7.4s, v3.8h, v0.8h \n"
"umull v18.4s, v4.4h, v0.4h \n"
"umull2 v17.4s, v4.8h, v0.8h \n"
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"uaddw v16.4s, v16.4s, v6.4h \n"
"uaddl2 v19.4s, v6.8h, v3.8h \n"
"uaddl v3.4s, v6.4h, v3.4h \n"
"uaddw2 v6.4s, v7.4s, v6.8h \n"
"uaddl2 v7.4s, v5.8h, v4.8h \n"
"uaddl v4.4s, v5.4h, v4.4h \n"
"uaddw v18.4s, v18.4s, v5.4h \n"
"prfm pldl1keep, [%1, 448] \n"
"mla v16.4s, v4.4s, v1.4s \n"
"mla v18.4s, v3.4s, v1.4s \n"
"mla v6.4s, v7.4s, v1.4s \n"
"uaddw2 v4.4s, v17.4s, v5.8h \n"
"uqrshrn v16.4h, v16.4s, #4 \n"
"mla v4.4s, v19.4s, v1.4s \n"
"uqrshrn2 v16.8h, v6.4s, #4 \n"
"uqrshrn v17.4h, v18.4s, #4 \n"
"uqrshrn2 v17.8h, v4.4s, #4 \n"
"st2 {v16.8h-v17.8h}, [%2], #32 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src_stride), // %1
"+r"(dst), // %2
"+r"(dst_width) // %3
: "r"(2LL), // %4
"r"(14LL) // %5
: "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", "v16", "v17", "v18",
"v19" // Clobber List
);
}
void ScaleUVRowDown2Box_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
uint8_t* dst,
int dst_width) {
asm volatile(
// change the stride to row 2 pointer
"add %1, %1, %0 \n"
"1: \n"
"ld2 {v0.16b,v1.16b}, [%0], #32 \n" // load 16 UV
"subs %w3, %w3, #8 \n" // 8 processed per loop.
"uaddlp v0.8h, v0.16b \n" // U 16 bytes -> 8 shorts.
"uaddlp v1.8h, v1.16b \n" // V 16 bytes -> 8 shorts.
"ld2 {v16.16b,v17.16b}, [%1], #32 \n" // load 16
"uadalp v0.8h, v16.16b \n" // U 16 bytes -> 8 shorts.
"uadalp v1.8h, v17.16b \n" // V 16 bytes -> 8 shorts.
"prfm pldl1keep, [%0, 448] \n" // prefetch 7 lines ahead
"rshrn v0.8b, v0.8h, #2 \n" // round and pack
"prfm pldl1keep, [%1, 448] \n"
"rshrn v1.8b, v1.8h, #2 \n"
"st2 {v0.8b,v1.8b}, [%2], #16 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src_stride), // %1
"+r"(dst), // %2
"+r"(dst_width) // %3
:
: "memory", "cc", "v0", "v1", "v16", "v17");
}
// Reads 4 pixels at a time.
void ScaleUVRowDownEven_NEON(const uint8_t* src_ptr,
ptrdiff_t src_stride,
int src_stepx, // pixel step
uint8_t* dst_ptr,
int dst_width) {
const uint8_t* src1_ptr = src_ptr + src_stepx * 2;
const uint8_t* src2_ptr = src_ptr + src_stepx * 4;
const uint8_t* src3_ptr = src_ptr + src_stepx * 6;
(void)src_stride;
asm volatile(
"1: \n"
"ld1 {v0.h}[0], [%0], %6 \n"
"ld1 {v1.h}[0], [%1], %6 \n"
"ld1 {v2.h}[0], [%2], %6 \n"
"ld1 {v3.h}[0], [%3], %6 \n"
"subs %w5, %w5, #4 \n" // 4 pixels per loop.
"st4 {v0.h, v1.h, v2.h, v3.h}[0], [%4], #8 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(src1_ptr), // %1
"+r"(src2_ptr), // %2
"+r"(src3_ptr), // %3
"+r"(dst_ptr), // %4
"+r"(dst_width) // %5
: "r"((int64_t)(src_stepx * 8)) // %6
: "memory", "cc", "v0", "v1", "v2", "v3");
}
#endif // !defined(LIBYUV_DISABLE_NEON) && defined(__aarch64__)
#ifdef __cplusplus
} // extern "C"
} // namespace libyuv
#endif