math broken on mips

math broken on mips

[Zhang Fuxin]

hi,
   There are so many problems on math handling for linux-mips,including:
1. SNaN & QNan handling(both gcc & glibc)
2. gcc2.96 generates wrong code with -O2,at least 
     one will lead to exception handling problem(reported by me)
     one will lead to some 'long long' type mishandling(reported by Atsushi Nemoto)

   (gcc3.1 seems a lot better,but it has problem to compile glibc.I can't even compile
 current glibc cvs code(with dl-conflict.c etc patched) with it. The best result is
 a segment fault when using ld.so.1:
      ../elf/ld.so.1 --library-path ..:../math:../elf:../dlfcn:../nss:../nis:../rt:../resolv:
  ../crypt:../linuxthreads ./rpcgen -Y ../scripts -c rpcsvc/bootparam_prot.x -o 
  xbootparam_prot.T
  make[1]: *** [xbootparam_prot.stmp] Segmentation fault
  )     
3. problems with math-emu
4. other problems to be investigated for its cause,including this one,
  
       pow(2,7) = 128.0 when rounding = TONEAREST or UPWARD
                = 64.1547.. when rounding = DOWNWARD or TOWARDZERO

 when today i find out the above problem I was feeling almost despaired:(

 I want to fix these problems,if i could.But it concerns so many things that i am not
 expert on and no time to dig:(. So any help will be highly appreciated.

 


Regards
            Zhang Fuxin
            fxzhang@ict.ac.cn

Re: math broken on mips

[H . J . Lu]

On Mon, Feb 18, 2002 at 03:57:04PM +0800, Zhang Fuxin wrote:
> 
>    (gcc3.1 seems a lot better,but it has problem to compile glibc.I can't even compile
>  current glibc cvs code(with dl-conflict.c etc patched) with it. The best result is
>  a segment fault when using ld.so.1:
>       ../elf/ld.so.1 --library-path ..:../math:../elf:../dlfcn:../nss:../nis:../rt:../resolv:
>   ../crypt:../linuxthreads ./rpcgen -Y ../scripts -c rpcsvc/bootparam_prot.x -o 
>   xbootparam_prot.T

You need to get the current glibc/gcc from CVS. You also need to apply
my glibc patches for mips if they are not in CVS yet. They are:

2002-01-20  H.J. Lu  <hjl@gnu.org>

        * config.make.in (inline-limit): New.

        * configure.in: Check if gcc supports -finline-limit=xxx.
        * configure: Rebuild.

        * elf/Makefile (CFLAGS-rtld.c): Set to -finline-limit=2000 if
        needed.

2002-02-04  H.J. Lu  <hjl@gnu.org>

        * elf/dl-conflict.c (_dl_resolve_conflicts): Dummy if
        _DL_HAVE_NO_ELF_MACHINE_RELA is defined.

2001-07-10  H.J. Lu  <hjl@gnu.org>

        * sysdeps/unix/sysv/linux/powerpc/mmap64.c: Moved to ...
        * sysdeps/unix/sysv/linux/mmap64.c: Here.

        * sysdeps/unix/sysv/linux/mmap64.c (MMAP2_PAGE_SHIFT): Renamed
        from PAGE_SHIFT. Define if not defined. Check MMAP2_PAGE_SHIFT
        only if __NR_mmap2 is defined.

        * sysdeps/unix/sysv/linux/hppa/mmap64.c : Removed.
        * sysdeps/unix/sysv/linux/sparc/sparc32/mmap64.c: Likewise.

Please check the glibc mailing list archive for those patches.


H.J.