[FFmpeg-devel] [PATCH 01/13] aarch64: vp9: use alternative returns in the core loop filter function
Martin Storsjö
martin at martin.st
Tue Jan 10 00:15:07 EET 2017
From: Janne Grunau <janne-libav at jannau.net>
Since aarch64 has enough free general purpose registers use them to
branch to the appropiate storage code. 1-2 cycles faster for the
functions using loop_filter 8/16, ... on a cortex-a53. Mixed results
(up to 2 cycles faster/slower) on a cortex-a57.
This is cherrypicked from libav commit
d7595de0b25e7064fd9e06dea5d0425536cef6dc.
---
libavcodec/aarch64/vp9lpf_neon.S | 48 +++++++++++++++-------------------------
1 file changed, 18 insertions(+), 30 deletions(-)
diff --git a/libavcodec/aarch64/vp9lpf_neon.S b/libavcodec/aarch64/vp9lpf_neon.S
index e727a4d..78aae61 100644
--- a/libavcodec/aarch64/vp9lpf_neon.S
+++ b/libavcodec/aarch64/vp9lpf_neon.S
@@ -410,15 +410,19 @@
.endif
// If no pixels needed flat8in nor flat8out, jump to a
// writeout of the inner 4 pixels
- cbz x5, 7f
+ cbnz x5, 1f
+ br x14
+1:
mov x5, v7.d[0]
.ifc \sz, .16b
mov x6, v7.d[1]
orr x5, x5, x6
.endif
// If no pixels need flat8out, jump to a writeout of the inner 6 pixels
- cbz x5, 8f
+ cbnz x5, 1f
+ br x15
+1:
// flat8out
// This writes all outputs into v2-v17 (skipping v6 and v16).
// If this part is skipped, the output is read from v21-v26 (which is the input
@@ -549,35 +553,24 @@ endfunc
function vp9_loop_filter_8
loop_filter 8, .8b, 0, v16, v17, v18, v19, v28, v29, v30, v31
- mov x5, #0
ret
6:
- mov x5, #6
- ret
+ br x13
9:
br x10
endfunc
function vp9_loop_filter_8_16b_mix
loop_filter 8, .16b, 88, v16, v17, v18, v19, v28, v29, v30, v31
- mov x5, #0
ret
6:
- mov x5, #6
- ret
+ br x13
9:
br x10
endfunc
function vp9_loop_filter_16
loop_filter 16, .8b, 0, v8, v9, v10, v11, v12, v13, v14, v15
- mov x5, #0
- ret
-7:
- mov x5, #7
- ret
-8:
- mov x5, #8
ret
9:
ldp d8, d9, [sp], 0x10
@@ -589,13 +582,6 @@ endfunc
function vp9_loop_filter_16_16b
loop_filter 16, .16b, 0, v8, v9, v10, v11, v12, v13, v14, v15
- mov x5, #0
- ret
-7:
- mov x5, #7
- ret
-8:
- mov x5, #8
ret
9:
ldp d8, d9, [sp], 0x10
@@ -614,11 +600,14 @@ endfunc
.endm
.macro loop_filter_8
+ // calculate alternative 'return' targets
+ adr x13, 6f
bl vp9_loop_filter_8
- cbnz x5, 6f
.endm
.macro loop_filter_8_16b_mix mix
+ // calculate alternative 'return' targets
+ adr x13, 6f
.if \mix == 48
mov x11, #0xffffffff00000000
.elseif \mix == 84
@@ -627,21 +616,20 @@ endfunc
mov x11, #0xffffffffffffffff
.endif
bl vp9_loop_filter_8_16b_mix
- cbnz x5, 6f
.endm
.macro loop_filter_16
+ // calculate alternative 'return' targets
+ adr x14, 7f
+ adr x15, 8f
bl vp9_loop_filter_16
- cmp x5, 7
- b.gt 8f
- b.eq 7f
.endm
.macro loop_filter_16_16b
+ // calculate alternative 'return' targets
+ adr x14, 7f
+ adr x15, 8f
bl vp9_loop_filter_16_16b
- cmp x5, 7
- b.gt 8f
- b.eq 7f
.endm
--
2.7.4
More information about the ffmpeg-devel
mailing list