--compile-type=debug doesn't compile with --arch=pentium3

[hansi.urpils@…]

Hi again!

I'm trying to compile MythTV with ./configure --compile-type=debug --arch=pentium3 because I've been asked to provide a backtrace in order to get #529 fixed. However, it "doesn't work"[tm], here's what I get:

make[2]: Entering directory `/home/laga/myth-bedtv/mythtv/libs/libavcodec'
[SNIP]
gcc -c -pipe -march=pentium3 -w -g -O -D_REENTRANT -DPIC -fPIC  -DMMX -Di386 -DUSING_DBOX2 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -DPREFIX=\"/usr/local\" -DHAVE_AV_CONFIG_H -D_LARGEFILE_SOURCE -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_NO_DEBUG -I/usr/share/qt3/mkspecs/default -I. -I.. -I../.. -I../libavutil -I/usr/include/qt3 -o mpegvideo_mmx.o i386/mpegvideo_mmx.c
In file included from i386/mpegvideo_mmx.c:678:
i386/mpegvideo_mmx_template.c: In function `dct_quantize_MMX':
i386/mpegvideo_mmx_template.c:105: error: can't find a register in class `GENERAL_REGS' while reloading `asm'
i386/mpegvideo_mmx_template.c:152: error: can't find a register in class `GENERAL_REGS' while reloading `asm'
make[2]: *** [mpegvideo_mmx.o] Error 1
make[2]: Leaving directory `/home/laga/myth-bedtv/mythtv/libs/libavcodec'
make[1]: *** [sub-libavcodec] Error 2
make[1]: Leaving directory `/home/laga/myth-bedtv/mythtv/libs'
make: *** [sub-libs] Error 2

I've found out so far that it works flawlessly when using --arch=i686 instead of --arch=pentium3 or with --compile-type=release --arch=pentium3. I've encountered this error for the first time on my Debian Sarge box, using either

gcc version 3.3.5 (Debian 1:3.3.5-13)

or

gcc version 3.4.4 20050314 (prerelease) (Debian 3.4.3-13)

The fact that it also doesn't work on my Gentoo box makes me think that it's a real bug and not just some oddity in my setup (feel free to correct me, however :))

As usual, I'll be glad to provide additional information.

Kind regards, Michael "laga" Haas

[danielk]

This is due to gcc's poor register allocation. You can safely comment out those two asm blocks, unless you need to decode H261 or H263, until we get around to fixing it.

It is still broken in ffmpeg proper...

[hansi.urpils@…]

Thanks, that works for me so far.

[danielk]

(In [7721]) Fixes #543.

Rejigs some of the asm constraints & uses a temp register, so that this file can be compiled without "--omit-frame-pointer"

[danielk]

Broken fix [7721], reverted in [7766]. I'll make a proper fix later this week.

[danielk]

(In [7833]) Fixes #542, hopefully without bad side-effects this time.

The problem with [7721] was the constraint change on line 118, which didn't do what I expected it too because of the type of qmat.

I've also kept one more parameter in a preloaded register this time in the H263 block, and got rid of the push/pop since it isn't needed with the REG_c reservation at the end of the asm blocks.

[anonymous]

Debian sid compile fails with these errors.

ccache gcc -c -pipe -march=pentium4 -w -Wall -Wno-switch -Os -fomit-frame-pointer -D_REENTRANT -DPIC -fPIC -DMMX -Di386 -DUSING_DBOX2 -DHAVE_DVDNAV -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -DPREFIX=\"/usr\" -DHAVE_AV_CONFIG_H -D_LARGEFILE_SOURCE -DHAVE_XVMC -DQT_NO_DEBUG -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_TABLET_SUPPORT -I/usr/share/qt3/mkspecs/default -I. -I.. -I../.. -I../libavutil -I../../../../include/qt3 -o mpegvideo_mmx.o i386/mpegvideo_mmx.c {standard input}: Assembler messages: {standard input}:896: Error: bad expression {standard input}:896: Error: missing ')' {standard input}:896: Error: missing ')' {standard input}:896: Error: junk `esp),%eax)' after expression {standard input}:1575: Error: bad expression {standard input}:1575: Error: missing ')' {standard input}:1575: Error: missing ')' {standard input}:1575: Error: junk `esp),%eax)' after expression {standard input}:2248: Error: bad expression {standard input}:2248: Error: missing ')' {standard input}:2248: Error: missing ')'

[danielk]

gcc 4.02 problem this was fixed in [7837].