[MPlayer-users] Illegal instruction crashes (SVN revs 26753 and 25993)

[Jan Knutar]

On Sunday 18 May 2008 13:00, Tobias Jakobi wrote:

> -O4 -march=i486 -mtune=i686 -pipe -ffast-math -fomit-frame-pointer
>
> Resulting in the use of SSE instr.
>
> With custom-cflags:
> -O2 -march=athlon-tbird -pipe -fomit-frame-pointer
> Producing a working build.
>
> Is this the mplayer Makefile or the gentoo ebuild?

MPlayer's configure's default behaviour is to optimize for the system it is
being built on, switching sse, mmx, etc on or off depending on the system's
capabilities. With MPlayer's configure, if you want to build without SSE on
a machine with SSE, you need to give --disable-sse option to configure. 

The use of sse wouldn't show up in CFLAGS or on the compiler commandline,
it's set in config.mak and config.h by configure.

Get MPlayer source from svn:

$ svn co svn://svn.mplayerhq.hu/mplayer/trunk mplayer

configure:

$ cd mplayer
$ ./configure --disable-sse --disable-sse2 --disable-ssse3

<...>
Check if sse was enabled:
$ grep SSE config.mak
$ grep SSE config.h
#define ENABLE_SSE 0
#define ENABLE_SSE2 0
#define ENABLE_SSSE3 0

Looks like it's disabled.

build:

$ make

<...>

And then let's check what the mplayer binary says:

$ ./mplayer
MPlayer dev-SVN-r26794-4.1.2 (C) 2000-2008 MPlayer Team
CPU: AMD Sempron(tm) Processor 3100+ (Family: 15, Model: 44, Stepping: 2)
SSE supported but disabled
SSE2 supported but disabled
CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 0 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx
<...>

So I'd go look in the direction of gentoo for figuring out how to disable SSE
in MPlayer ebuild, if such a thing can be done.