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volume: Add Orc-based optimised volume scaling

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This adds volume scaling for 1- and 2-channel software volume scaling
using Orc. While testing the MMX and SSE backends on a Core2, I see an
~2x performance benefit over the hand-rolled MMX and SSE code. Since I
haven't been able to test on other architectures, the Orc code is only
used when MMX/SSE* is present. This can be changed in the future after
testing on AMD and ARM machines.
This commit is contained in:
Arun Raghavan 2010-10-25 17:59:08 +01:00
parent 516dd169b4
commit 4cd90d9e32
6 changed files with 282 additions and 0 deletions
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src/pulsecore/svolume.orc Normal file
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# This file is part of PulseAudio.
#
# Copyright 2010 Lennart Poettering
# Copyright 2010 Wim Taymans <wim.taymans@collabora.co.uk>
# Copyright 2010 Arun Raghavan <arun.raghavan@collabora.co.uk>
#
# PulseAudio is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation; either version 2.1 of the License,
# or (at your option) any later version.
#
# PulseAudio is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with PulseAudio; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA.
# S16NE 1- and 2-channel volume scaling work as follows:
#
# params: samples s (signed 16-bit), volume v (signed 32-bit < 2^31)
#
# 32 16 0 (type of operation)
# sample = | sample | (signed)
# s = | 0 | sample | (unsigned)
#
# if (sample < 0)
# signc = | 0 | 0xffff | (unsigned)
# else
# signc = | 0 | 0 | (unsgined)
#
# if (sample < 0)
# ml = | 0 | -((s*vl) >> 16) | (unsgined)
# else
# ml = | 0 | (s*vl) >> 16 | (unsgined)
#
# vh = | v >> 16 | (signed, but value is always signed
# since PA_VOLUME_MAX is 0x0fffffff)
# mh = | (s * vh) >> 16 | (signed)
# ml = | ml + mh | (signed)
# sample = | (ml >> 16) | (signed, saturated)
.function pa_volume_s16ne_orc_1ch
.dest 2 samples int16_t
.param 4 v int32_t
.temp 2 vh
.temp 4 s
.temp 4 mh
.temp 4 ml
.temp 4 signc
convuwl s, samples
x2 cmpgtsw signc, 0, s
x2 andw signc, signc, v
x2 mulhuw ml, s, v
subl ml, ml, signc
convhlw vh, v
mulswl mh, samples, vh
addl ml, ml, mh
convssslw samples, ml
.function pa_volume_s16ne_orc_2ch
.dest 4 samples int16_t
.longparam 8 vols
.temp 8 v
.temp 4 vh
.temp 8 s
.temp 8 mh
.temp 8 ml
.temp 8 signc
loadpq v, vols
x2 convuwl s, samples
x4 cmpgtsw signc, 0, s
x4 andw signc, signc, v
x4 mulhuw ml, s, v
x2 subl ml, ml, signc
x2 convhlw vh, v
x2 mulswl mh, samples, vh
x2 addl ml, ml, mh
x2 convssslw samples, ml