Bug 87809 – Patch for libsdl ebuild to compile with gcc4

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Genady Okrain 2005-04-03 10:04:57 UTC]

Yep its ugly too.

Reproducible: Always
Steps to Reproduce:
1.
2.
3.

[Comment 1 Genady Okrain 2005-04-03 10:05:10 UTC]

Created attachment 55206 [details]
libsdl-1.2.8-r1.ebuild.patch

[Comment 2 SpanKY 2005-04-03 10:06:59 UTC]

yeah, that patch def does not look like we can accept it ...

perhaps it'd be better to fix the source code than disable features ? :p

[Comment 3 Genady Okrain 2005-04-03 10:24:08 UTC]

Yes I know, but its a temporal fix.

[Comment 4 SpanKY 2005-04-03 10:29:56 UTC]

temporal fixes for gcc4 dont go into portage

[Comment 5 Mr. Bones. (RETIRED) 2005-04-05 19:08:42 UTC]

gcc-4 isn't supported right now.  If you supply a non-hackish patch to address this, reopen and we'll take a look.

[Comment 6 Genady Okrain 2005-04-14 23:34:04 UTC]

New patch for gcc4 is here.

Tested without gcc2 patchs.

[Comment 7 Genady Okrain 2005-04-14 23:35:06 UTC]

Created attachment 56322 [details]
SDL-1.2.8-gcc4.patch

[Comment 8 Mark Loeser (RETIRED) 2005-05-03 23:54:12 UTC]

This patch is applied in portage, but you can only compile libsdl with -O0 because of libsdl-1.2.8-gcc2.patch.bz2.  Removing it allows you to compile libsdl fine with regular optimizations.  I don't know enough asm to know what sort of voodoo is happening there and why it would be screwing GCC4 up.  Anyone else have any ideas?  

When the patch is applied, the error GCC4 gives is:

 i686-pc-linux-gnu-gcc -DPACKAGE_NAME=\"\" -DPACKAGE_TARNAME=\"\" -DPACKAGE_VERSION=\"\" -DPACKAGE_STRING=\"\" -DPACKAGE_BUGREPORT=\"\" -DPACKAGE=\"SDL\" -DVERSION=\"1.2.8\" -DSTDC_HEADERS=1 -DHAVE_SYS_TYPES_H=1 -DHAVE_SYS_STAT_H=1 -DHAVE_STDLIB_H=1 -DHAVE_STRING_H=1 -DHAVE_MEMORY_H=1 -DHAVE_STRINGS_H=1 -DHAVE_INTTYPES_H=1 -DHAVE_STDINT_H=1 -DHAVE_UNISTD_H=1 -DHAVE_DLFCN_H=1 -DHAVE_ALLOCA_H=1 -DHAVE_ALLOCA=1 -DHAVE_LIBASOUND=1 -I. -I. -mtune=athlon-mp -march=athlon-mp -O2 -fomit-frame-pointer -pipe -ftracer -fweb -ftree-vectorize -Wall -DENABLE_DUMMYVIDEO -DDISKAUD_SUPPORT -DUSE_DLOPEN -DUSE_ASMBLIT -I./hermes -I../../src/hermes -DALSA_SUPPORT -DALSA_DYNAMIC=libasound.so.2 -DUSE_DLVSYM -DESD_SUPPORT -DESD_DYNAMIC=libesd.so.0 -DENABLE_X11 -DXTHREADS -I./include -I./src/video -DXFREE86_VM -DXFREE86_VMGAMMA -DXFREE86_XV -DENABLE_SVGALIB -DHAVE_OPENGL -DUSE_INPUT_EVENTS -D_REENTRANT -DSDL_USE_PTHREADS -DHAVE_SIGACTION -I../../include -I../../include/SDL -I../../src -I../../src/main/linux -I../../src/audio -I../../src/video -I../../src/video/XFree86/extensions -I../../src/events -I../../src/joystick -I../../src/cdrom -I../../src/thread -I../../src/timer -I../../src/endian -I../../src/file -I../../src/thread -c SDL_yuv_mmx.c  -fPIC -DPIC -o .libs/SDL_yuv_mmx.o
SDL_yuv_mmx.c: In function 'ColorRGBDitherYV12MMX1X':
SDL_yuv_mmx.c:113: error: can't find a register in class 'INDEX_REGS' while reloading 'asm'
make[3]: *** [SDL_yuv_mmx.lo] Error 1

[Comment 9 Robin Johnson 2005-05-05 03:10:57 UTC]

halcy0n: Saw this bug in your blog. 

the source of the asm error is reasonably simple.
under higher -O levels, GCC tries to preserve values in registers longer to re-use them. 

x86 is a sucky architecture, in that only a very small number of registers are available - the error you see is that it wants 5 registers for that asm block, but 5 registers aren't available at that point.
I suspect that the problem would go away if you added the list of registers that is clobbered to the correct section of the asm code (look it up in 'info gcc'), then things should be more sane.

[Comment 10 Mark Loeser (RETIRED) 2005-05-14 17:29:22 UTC]

Modifying that patch is a little beyond me.  If someone wants to fix it, go for it, but for now, I made it so the patch is conditionally applied and only isn't applied for gcc 4.  So, now compiling libsdl with >-O0 should work fine.