Steven M. Schultz wrote:
> Hi -
>
> If you're using gcc 3.3 (as SuSE 8.2 does) and the building
> of the jpeg-mmx library fails with:
>
> gcc -O6 -I. -c -o jdapimin.o jdapimin.c
> /tmp/cc7IfzBn.s: Assembler messages:
> /tmp/cc7IfzBn.s:619: Error: symbol `NOT_SUPPORTED' is already defined
> gmake: *** [jdapimin.o] Error 1
>
The reason for this it that gcc inlines the assembler function
mmxsupport() at 2 places, so the symbol NOT_SUPPORTED is defined twice.
A fix without changing the O option is to change the global symbol to a
local one. See the attached patch.
Wolfgang
> Here is a patch to fix the problem - it seems that -O6 is too high
> and causes the module to be miscompiled somehow. Changing that to
> -O2 fixes the problem:
>
> --- Makefile.dist 2002-04-25 09:09:18.000000000 -0700
> +++ Makefile 2003-05-29 22:00:54.000000000 -0700
> @@ -25,7 +25,7 @@
> AS= nasm
> ASFLAGS = -f elf
> # You may need to adjust these cc options:
> -CFLAGS= -O6 -I$(srcdir)
> +CFLAGS= -O2 -I$(srcdir)
> # Generally, we recommend defining any configuration symbols in jconfig.h,
> # NOT via -D switches here.
> # However, any special defines for ansi2knr.c may be included here:
>
> Cheers,
> Steven Schultz
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: eBay
> Get office equipment for less on eBay!
> http://adfarm.mediaplex.com/ad/ck/711-11697-6916-5
> _______________________________________________
> Mjpeg-users mailing list
> [EMAIL PROTECTED]
> https://lists.sourceforge.net/lists/listinfo/mjpeg-users
>
diff -ur ../jpeg-mmx-0.1.4.org/jdapimin.c ./jdapimin.c
--- ../jpeg-mmx-0.1.4.org/jdapimin.c 2000-09-19 18:04:22.000000000 +0200
+++ ./jdapimin.c 2003-05-01 14:32:10.000000000 +0200
@@ -471,16 +471,16 @@
"pushfl \n\t" //Save Eflag to stack
"popl %%eax \n\t" //Get Eflag from stack
"xorl %%ecx,%%eax \n\t" //Compare the new Eflag with the
original Eflag
- "jz NOT_SUPPORTED \n\t" //If the same, CPUID instruction
is not supported,
+ "jz 1f \n\t" //If the same, CPUID instruction is not
supported,
//skip following
instructions and jump to
- //NOT_SUPPORTED label
+ //1f label
"xorl %%eax,%%eax \n\t" //Set eax to zero
"cpuid \n\t" //CPUID instruction (two bytes
opcode)
"cmpl $1,%%eax \n\t" //make sure eax return
non-zero value
- "jl NOT_SUPPORTED \n\t" //If eax is zero, mmx not supported
+ "jl 1f \n\t" //If eax is zero, mmx not supported
"xorl %%eax,%%eax \n\t" //set eax to zero
"incl %%eax \n\t" //Now increment eax to 1.
This instruction is
@@ -489,11 +489,11 @@
"andl $0x00800000,%%edx \n\t" //mask out all bits but mmx
bit(24)
"cmpl $0,%%edx \n\t" // 0 = mmx not supported
- "jz NOT_SUPPORTED \n\t" // non-zero = Yes, mmx IS supported
+ "jz 1f \n\t" // non-zero = Yes, mmx IS supported
"movl $1, mmx_supported \n\t"
- "NOT_SUPPORTED: \n\t"
+ "1: \n\t"
"movl $mmx_supported, %%eax" //move return value to eax
Only in .: jdapimin.c~
