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arm: add ff_int32_to_float_fmul_array8_neon

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Quite a bit faster than int32_to_float_fmul_array8_c calling
ff_int32_to_float_fmul_scalar_neon through FmtConvertContext.
Number of cycles per int32_to_float_fmul_array8 call while decoding
padded.dts on exynos5422:

               before  after   change
cortex-a7:     1270     951    -25%
cortex-a15:     434     285    -34%

checkasm --bench cycle counts:     cortex-a15   cortex-a7
int32_to_float_fmul_array8_c:      1730.4       4384.5
int32_to_float_fmul_array8_neon_c:  571.5       1694.3
int32_to_float_fmul_array8_neon:    374.0       1448.8

Interesting are the differences between
int32_to_float_fmul_array8_neon_c and int32_to_float_fmul_array8_neon.
The former is current behaviour of calling
ff_int32_to_float_fmul_scalar_neon repeatedly from the c function,
The raw numbers differ since checkasm uses different lengths than the
dca decoder.
This commit is contained in:
Janne Grunau 2015-12-03 16:17:32 +01:00
parent a0fc780a20
commit 90b1b9350c
2 changed files with 41 additions and 0 deletions
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4
libavcodec/arm/fmtconvert_init_arm.c
View File

@ -25,6 +25,9 @@
#include "libavcodec/avcodec.h"
#include "libavcodec/fmtconvert.h"
void ff_int32_to_float_fmul_array8_neon(FmtConvertContext *c, float *dst,
const int32_t *src, const float *mul,
int len);
void ff_int32_to_float_fmul_scalar_neon(float *dst, const int32_t *src,
float mul, int len);
@ -46,6 +49,7 @@ av_cold void ff_fmt_convert_init_arm(FmtConvertContext *c, AVCodecContext *avctx
}
if (have_neon(cpu_flags)) {
c->int32_to_float_fmul_array8 = ff_int32_to_float_fmul_array8_neon;
c->int32_to_float_fmul_scalar = ff_int32_to_float_fmul_scalar_neon;
}
}

37
libavcodec/arm/fmtconvert_neon.S
View File

@ -1,6 +1,7 @@
/*
* ARM NEON optimised Format Conversion Utils
* Copyright (c) 2008 Mans Rullgard <mans@mansr.com>
* Copyright (c) 2015 Janne Grunau <janne-libav@jannau.net>b
*
* This file is part of Libav.
*
@ -49,3 +50,39 @@ NOVFP len .req r3
bx lr
.unreq len
endfunc
function ff_int32_to_float_fmul_array8_neon, export=1
ldr r0, [sp]
lsr r0, r0, #3
subs r0, r0, #1
beq 1f
2:
vld1.32 {q0-q1}, [r2,:128]!
vld1.32 {q2-q3}, [r2,:128]!
vld1.32 {d20}, [r3]!
subs r0, r0, #2
vcvt.f32.s32 q0, q0
vcvt.f32.s32 q1, q1
vdup.32 q8, d20[0]
vcvt.f32.s32 q2, q2
vcvt.f32.s32 q3, q3
vmul.f32 q0, q0, q8
vdup.32 q9, d20[1]
vmul.f32 q1, q1, q8
vmul.f32 q2, q2, q9
vmul.f32 q3, q3, q9
vst1.32 {q0-q1}, [r1,:128]!
vst1.32 {q2-q3}, [r1,:128]!
bgt 2b
it lt
bxlt lr
1:
vld1.32 {q0-q1}, [r2,:128]
vld1.32 {d16[],d17[]}, [r3]
vcvt.f32.s32 q0, q0
vcvt.f32.s32 q1, q1
vmul.f32 q0, q0, q8
vmul.f32 q1, q1, q8
vst1.32 {q0-q1}, [r1,:128]
bx lr
endfunc