[vlc-devel] commit: contrib: turn off Thumb ISA for libavcodec and libmad ( Rémi Denis-Courmont )
remi at remlab.net
Tue Sep 1 20:20:12 CEST 2009
Le samedi 29 août 2009 23:19:51 Måns Rullgård, vous avez écrit :
> > A solution would be to build the files containing inline ARM asm with
> > -mno-thumb -mthumb-interwork but you'd have to check every file
> > Last but not least: thumb is quite limited and considered slower than
> > ARM code (note thumb-2 appears to be generally faster than thumb) so
> > it's not advised for multimedia routines especially when you have loads
> > of memory available and code size doesn't matter that much.
A few compile+SFTP cycles later, it turns out that:
* VLC with Thumb, and avcodec with interwork fires SIGILL.
-> It works fine with everything built as ARM
(and no interworking of course).
* FFMPEG triggers a segmentation fault when NEON FPU is enabled.
-> FFMPEG with "default" FPU and VLC with NEON FPU works
(but surely not so fast).
This smells a lot like a bug in avcodec (or gcc).
This is all built with CodeSourcery 2007q3 ARMv7 toolchain (GCC 4.2.1).
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