Re: [ts-7000] Floating point

[Etienne Chenard <>]

Hi Eddie,

On Wed, 2006-03-29 at 12:16 -0700, Eddie Dawydiuk wrote:
> > No, not directly, however the glibc version of _dtoa that the gnu
> > classpath from java calls seems to be wonky
> >
> > I get numbers like 25.0000000876 for 25.0
> 
> In the past people have had problems with using different version of
> gcc when crosscompiling. Also there was a problem with glibc about
> a year ago that has been corrected...
> 
> So if you run the following program what is the output?
> 
> 
>    #include <stdio.h>
>    int main(int argc, char **argv) {
> 
>            double d = 25.0;
>            printf("25.0 = %10.10f\n",d);
>            return 0;
>    }

I Get 
$ ./test
25.0 = 25.0000000000

But if I run:

#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {

  double d = strtod("25.0", NULL);
  printf("25.0 = %10.10f\n",d);
  return 0;
}

I Get:
$ ./test
25.0 = 0.0000000000

Software and Hardware:
$ uname -a
Linux aptwo 2.4.26-vrs1-cirrus-1-2-1-ts8 #1 Mon Mar 7 09:55:33 MST 2005
armv4l unknown

Armgcc crosstools on my PC:
$ arm-linux-gcc -v
Reading specs
from 
/usr/local/opt/crosstool/arm-linux/gcc-3.3.4-glibc-2.3.2/lib/gcc-lib/arm-linux/3.3.4/specs
Configured
with: 
/home/liberty/work_stuff/xtool/crosstool-0.28-rc37/build/arm-linux/gcc-3.3.4-glibc-2.3.2/gcc-3.3.4/configure
 --target=arm-linux --host=i686-host_pc-linux-gnu 
--prefix=/usr/local/opt/crosstool/arm-linux/gcc-3.3.4-glibc-2.3.2 
--with-headers=/usr/local/opt/crosstool/arm-linux/gcc-3.3.4-glibc-2.3.2/arm-linux/include
 
--with-local-prefix=/usr/local/opt/crosstool/arm-linux/gcc-3.3.4-glibc-2.3.2/arm-linux
 --disable-nls --enable-threads=posix --enable-symvers=gnu 
--enable-__cxa_atexit --enable-languages=c,c++ --enable-shared --enable-c99 
--~/workplace/testenable-long-long
Thread model: posix
gcc version 3.3.4


I hope this will help you

Thanks

Etienne

> 
> I've also included a binary to help troubleshoot the problem...
> 
> //Eddie
> 
> > On 24-Mar-06, at 7:44 PM, Yan Seiner wrote:
> >
> >> Has anyone worked with floating point on this board?  I am
> >> experiencing some problems - getting garbage and segfaults while
> >> using floating point math - and I want to eliminate the kernel
> >> emulation code as a possible source.
> >>
> >> I doubt it is the kernel code, but I want to make sure....
> >>
> >> --Yan
> >>
> >>
> >>
> >>
> >>
> >>
> >> Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  





 
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