[mythtv] Weird avcodec compile problem

[Kenneth Aafløy]

> On Sat, 20 Dec 2003 02:23:29 +0100, "Kenneth Aafløy" said:
> > 
> > Geoffrei Haushner wrote:
> > 
> > > Yeah, but it is pretty hard to debug problems with -O3 set 
> > > (it reorders
> > > the execution commands)
> > > 
> > > For some reason dsputil_mmx.c won't compile without a '-O' 
> > > setting (and
> > > '-O0' doesn't work).
> > > 
> > > I suppose I could just disable MMX for debug, but that'll kill my
> > > performance, and valgrind supoorts MMX ok nowadays.
> > 
> > Try forcing mmx with debug flags adding to settings.pro:
> > 
> > QMAKE_C[?:XX]FLAGS_DEBUG += -mmmx
> > 
> Nope, no luck:
> gcc -c -pipe -w -mmmx -g -DHAVE_AV_CONFIG_H -I.. 
> -D_FILE_OFFSET_BITS=64
> -D_LARGEFILE_SOURCE -D_GNU_SOURCE -D_REENTRANT  -D_GNU_SOURCE
> -D_FILE_OFFSET_BITS=64 -DPREFIX=\"/usr/local\" -DMMX 
> -DQT_THREAD_SUPPORT
> -DQT_SHARED -DQT_NO_DEBUG -I/usr/share/qt3/mkspecs/default -I. -I../..
> -I../../../../../../include/qt3 -o dsputil_mmx.o i386/dsputil_mmx.c
> i386/dsputil_mmx.c: In function `h263_h_loop_filter_mmx':
> i386/dsputil_mmx.c:610: error: can't find a register in class
> `GENERAL_REGS' while reloading `asm'
> 
> Is this a gcc bug?  I know nothing about inline assembly, and this
> message is meaningless to me.  Seems pretty weird to require an
> optimization flag tho.

It is because the compiler has not loaded the mmx instruction set,
unless I'm wrong, which is 99% of the time, have you tried a -march=xxx
flag?

Kenneth