generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

PPC asm for AV_RL*()

Browse Source 
PPC is normally big endian but has special little endian load/store
instructions.  Using these avoids a separate byteswap.  This makes the
vorbis decoder about 5% faster.  Not much else uses little-endian
read/write extensively.

GCC generates horrible PPC code for the default AV_[RW]B64 (which uses
a packed struct), so we override it with a plain pointer cast.

Originally committed as revision 18602 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Måns Rullgård 2009-04-18 00:00:31 +00:00
parent 3c55ce039d
commit 9f5ff83f2a
3 changed files with 108 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
configure vendored
View File

@ -890,6 +890,7 @@ HAVE_LIST="
getrusage
inet_aton
inline_asm
ldbrx
libdc1394_1
libdc1394_2
llrint
@ -1807,7 +1808,7 @@ if test $cpu != "generic"; then
Cell|CELL|cell)
add_cflags -mcpu=cell
warn_altivec disabled Cell
enable ppc64
enable ppc64 ldbrx
;;
# targets that do NOT support conditional mov (cmov)
i[345]86|pentium|pentium-mmx|k6|k6-[23]|winchip-c6|winchip2|c3)

2
libavutil/intreadwrite.h
View File

@ -31,6 +31,8 @@
#if ARCH_ARM
# include "arm/intreadwrite.h"
#elif ARCH_PPC
# include "ppc/intreadwrite.h"
#endif
/*

104
libavutil/ppc/intreadwrite.h Normal file
View File

@ -0,0 +1,104 @@
/*
* Copyright (c) 2008 Mans Rullgard <mans@mansr.com>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVUTIL_PPC_INTREADWRITE_H
#define AVUTIL_PPC_INTREADWRITE_H
#include <stdint.h>
#include "config.h"
#define AV_RL16 AV_RL16
static inline uint16_t AV_RL16(const void *p)
{
uint16_t v;
__asm__ ("lhbrx %0, %y1" : "=r"(v) : "Z"(*(const uint16_t*)p));
return v;
}
#define AV_WL16 AV_WL16
static inline void AV_WL16(void *p, uint16_t v)
{
__asm__ ("sthbrx %1, %y0" : "=Z"(*(uint16_t*)p) : "r"(v));
}
#define AV_RL32 AV_RL32
static inline uint32_t AV_RL32(const void *p)
{
uint32_t v;
__asm__ ("lwbrx %0, %y1" : "=r"(v) : "Z"(*(const uint32_t*)p));
return v;
}
#define AV_WL32 AV_WL32
static inline void AV_WL32(void *p, uint32_t v)
{
__asm__ ("stwbrx %1, %y0" : "=Z"(*(uint32_t*)p) : "r"(v));
}
#if HAVE_LDBRX
#define AV_RL64 AV_RL64
static inline uint64_t AV_RL64(const void *p)
{
uint64_t v;
__asm__ ("ldbrx %0, %y1" : "=r"(v) : "Z"(*(const uint64_t*)p));
return v;
}
#define AV_WL64 AV_WL64
static inline void AV_WL64(void *p, uint64_t v)
{
__asm__ ("stdbrx %1, %y0" : "=Z"(*(uint64_t*)p) : "r"(v));
}
#else
#define AV_RL64 AV_RL64
static inline uint64_t AV_RL64(const void *p)
{
union { uint64_t v; uint32_t hl[2]; } v;
__asm__ ("lwbrx %0, %y2 \n\t"
"lwbrx %1, %y3 \n\t"
: "=r"(v.hl[1]), "=r"(v.hl[0])
: "Z"(*(const uint32_t*)p), "Z"(*((const uint32_t*)p+1)));
return v.v;
}
#define AV_WL64 AV_WL64
static inline void AV_WL64(void *p, uint64_t v)
{
union { uint64_t v; uint32_t hl[2]; } vv = { v };
__asm__ ("stwbrx %2, %y0 \n\t"
"stwbrx %3, %y1 \n\t"
: "=Z"(*(uint32_t*)p), "=Z"(*((uint32_t*)p+1))
: "r"(vv.hl[1]), "r"(vv.hl[0]));
}
#endif /* HAVE_LDBRX */
/*
* GCC fails miserably on the packed struct version which is used by
* default, so we override it here.
*/
#define AV_RB64(p) (*(const uint64_t *)(p))
#define AV_WB64(p, v) (*(uint64_t *)(p) = (v))
#endif /* AVUTIL_PPC_INTREADWRITE_H */