[MPlayer-dev-eng] -mieee CFLAG missing on alpha (patch included)

[Guillaume Poirier]

Hi,

Thomas Cort wrote:
> mplayer-1.0_pre7 plays wav and ogg files without a problem, but
> crashes when attempting to play mp3 files. I re-compiled mplayer with
> debug enabled and ran it in gdb. Output below:
> 
> 
> 
> tcort at pan ~ $ gdb mplayer
> GNU gdb 6.3
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "alpha-unknown-linux-gnu"...Using host libthread_db
> library "/lib/libthread_db.so.1".
> 
> (gdb) run /exports/music/Raffi_-_Bananaphone.mp3
> Starting program: /usr/bin/mplayer /exports/music/Raffi_-_Bananaphone.mp3
> [Thread debugging using libthread_db enabled]
> [New Thread 2199023420624 (LWP 27771)]
> Using GNU internationalization
> Original domain: messages
> Original dirname: /usr/share/locale
> Current domain: mplayer
> Current dirname: /usr/share/locale
> 
> MPlayer 1.0pre7try2-3.3.5 (C) 2000-2005 MPlayer Team
> CPU: Digital Alpha
> 
> 
> 85 audio & 196 video codecs
> Playing /exports/music/Raffi_-_Bananaphone.mp3.
> Cache fill:  0.00% (0 bytes)    Audio file detected.
> Clip info:
>  Title: Bananaphone
>  Artist: Raffi
>  Album: Bananaphone
>  Year:
>  Comment:
>  Track: 1
>  Genre: Unknown
> ==========================================================================
> Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
> 
> Program received signal SIGFPE, Arithmetic exception.
> [Switching to Thread 2199023420624 (LWP 27771)]
> 0x0000000120155d7c in demux_audio_fill_buffer (ds=0x120726b30) at demuxer.h:218
> 218     demuxer.h: No such file or directory.
>         in demuxer.h
> (gdb) quit
> The program is running.  Exit anyway? (y or n) y
> 
> 
> 
> As you can see, there was a SIGFPE (floating-point exception). This is because
> mplayer doesn't set CFLAGS="-mieee $CFLAGS". However, the alpha
> architecture needs -mieee in CFLAGS to do some (maybe all?)
> floating-point operations.
> 
> Quote from the -mieee section of the gcc-3.3.5 man page:
> "The Alpha architecture implements floating-point hardware optimized
> for maximum performance.  It is mostly compliant with the IEEE
> floating point standard.  However, for full compliance, software
> assistance is required.  This option generates code fully IEEE com-
> pliant code except that the inexact-flag is not maintained (see
> below).  If this option is turned on, the preprocessor macro
> "_IEEE_FP" is defined during compilation.  The resulting code is
> less efficient but is able to correctly support denormalized num-
> bers and exceptional IEEE values such as not-a-number and
> plus/minus infinity.  Other Alpha compilers call this option
> -ieee_with_no_inexact."
> 
> I patched the configure script to add "-mieee" to CFLAGS if arch is
> alpha. mp3 playback works fine now. The patch is attached.
> 
> There is a Gentoo bug about this here:
> http://bugs.gentoo.org/show_bug.cgi?id=113857
> 
> -Thomas Cort

I don't think that any dev has access to such a [splendid kick-ass ]
machine, so unless someone strongly disagrees, I'm gonna trust you
Thomas that it works, and commit smth similar to CVS during the week.

Thomas, note that patches are expected to be written against CVS version
of MPlayer, but in this particular case, it doesn't matter.

Guillaume