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Re: using ARM VFP hardware
On Mon, 2009-11-09 at 09:31 -0800, Ian Lance Taylor wrote:
> Ineiev <ineiev@gmail.com> writes:
>
> > After that I compile a test:
> > int
> > main(int argc,char**argv)
> > {double x=argc*.17,y=argc*2-.1;
> > return(int)(x/y+y*x);
> > }
> >
> > arm-unknown-elf-gcc -Wall -O0 -nostdlib \
> > -mfpu=vfp -mfloat-abi=soft -o e e.c -lgcc
> >
> > Then I look for instructions whose name begins with f
>
> Using -mfloat=abi=soft directs gcc to call floating point emulation
> routines. Have you tried -mfloat-abi=softfp or -mfloat-abi=hard?
>
> > ../gcc-4.4.1/configure --prefix=$HOME/arm \
> > --target=arm-unknown-elf --enable-interwork \
> > --disable-nls --with-mpfr=$HOME/mpfr \
> > --disable-libssp --enable-languages=c \
> > --with-fpu=vfp --with-cpu=arm946e-s --with-float=soft \
>
> Using --with-float=soft makes soft floating point the default. If you
> don't want soft floating point, what led you to use --with-float=soft?
>
> Ian
-mfloat-abi=hard will only work with gcc-4.5 (ie trunk)
R.