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Commit e200738d authored by Frank Barchard's avatar Frank Barchard
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Scale Down by 2 use ld2 and urhadd 

urhadd is a rounded average.  Linear filter wants to average
horizontally, so use ld2 to separate even and odd pixels.

TBR=jkellander@chromium.org
BUG=None
TEST=LibYUVScaleTest.*ScaleDownBy2*

Change-Id: Id667288a030e72ce8e1c1d6719b69c555c0db063
Reviewed-on: https://chromium-review.googlesource.com/642448
Commit-Queue: Frank Barchard <fbarchard@google.com>
Reviewed-by: 's avatarCheng Wang <wangcheng@google.com>
parent b6e8e9aa
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Showing with 16 additions and 27 deletions
source/scale_neon64.cc
View file @ e200738d
......@@ -49,14 +49,10 @@ void ScaleRowDown2Linear_NEON(const uint8* src_ptr,
(void)src_stride;
asm volatile(
"1: \n"
"ld1 {v0.16b,v1.16b}, [%0], #32 \n" // load pixels and post
// inc
// load even pixels into v0, odd into v1
"ld2 {v0.16b,v1.16b}, [%0], #32 \n"
"urhadd v0.16b, v0.16b, v1.16b \n" // rounding half add
"subs %w2, %w2, #16 \n" // 16 processed per loop
"uaddlp v0.8h, v0.16b \n" // add adjacent
"uaddlp v1.8h, v1.16b \n"
"rshrn v0.8b, v0.8h, #1 \n" // downshift, round and
// pack
"rshrn2 v0.16b, v1.8h, #1 \n"
"st1 {v0.16b}, [%1], #16 \n"
"b.gt 1b \n"
: "+r"(src_ptr), // %0
......@@ -726,13 +722,12 @@ void ScaleARGBRowDown2_NEON(const uint8* src_ptr,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load even pixels into q0, odd into q1
"ld2 {v0.4s, v1.4s}, [%0], #32 \n"
"ld2 {v2.4s, v3.4s}, [%0], #32 \n"
"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
"st1 {v1.16b}, [%1], #16 \n" // store odd pixels
"st1 {v3.16b}, [%1], #16 \n"
"mov v2.16b, v3.16b \n"
"st2 {v1.4s,v2.4s}, [%1], #32 \n" // store 8 odd pixels
"b.gt 1b \n"
: "+r"(src_ptr), // %0
"+r"(dst), // %1
......@@ -748,20 +743,14 @@ void ScaleARGBRowDown2Linear_NEON(const uint8* src_argb,
int dst_width) {
(void)src_stride;
asm volatile(
"1: \n"
// load 8 ARGB pixels.
"ld4 {v0.16b,v1.16b,v2.16b,v3.16b}, [%0], #64 \n"
"subs %w2, %w2, #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.
"rshrn v0.8b, v0.8h, #1 \n" // downshift, round and
// pack
"rshrn v1.8b, v1.8h, #1 \n"
"rshrn v2.8b, v2.8h, #1 \n"
"rshrn v3.8b, v3.8h, #1 \n"
"st4 {v0.8b,v1.8b,v2.8b,v3.8b}, [%1], #32 \n"
"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
"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
......
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