[FFmpeg-devel] Question about -fPIC usage for some files

[Thorsten Jordan]

Michael Niedermayer schrieb:
> On Fri, Feb 08, 2008 at 02:10:53PM +0100, Thorsten Jordan wrote:
> [...]
>> what about the idea of possible extension of the Makefile(s) for extra
>> flags of libavcodec/i386/* ?
> 
> Why does it fail with pic for you?
the same problem that was discussed several times on this list, gcc
fails to generate the code because it runs out of registers (ebx is used
with -fPIC):


here are the errors (gcc compile line filtered out):


In file included from i386/dsputil_mmx.c:30:
i386/mmx.h:24:2: warning: #warning Everything in this header is
deprecated, use plain asm()! New code using this header will be rejected.
i386/h264dsp_mmx.c: In function ?put_h264_qpel4_h_lowpass_3dnow?:
i386/h264dsp_mmx.c:1881: error: can't find a register in class
?GENERAL_REGS? while reloading ?asm?


i386/cavsdsp_mmx.c: In function ?ff_put_cavs_qpel8_mc01_3dnow?:
i386/cavsdsp_mmx.c:447: error: can't find a register in class
?GENERAL_REGS? while reloading ?asm?


i386/flacdsp_mmx.c: In function ?ff_flac_compute_autocorr_sse2?:
i386/flacdsp_mmx.c:87: error: can't find a register in class
?GENERAL_REGS? while reloading ?asm?


compile flags used (except includes):
 -fPIC -fomit-frame-pointer -march=i686 -pthread -g
-Wdeclaration-after-statement -Wall -Wno-switch -Wdisabled-optimization
-Wpointer-arith -Wredundant-decls -Wno-pointer-sign -Wcast-qual
-Wwrite-strings -O3

-- 
Regards, Thorsten