[uClibc] 386 floating point

[Jeffrey Baitis]

I know it's a bit off-topic, but over here, we've found that using the
Algorithmics soft-float emulator on MIPS is 5x slower. Here were the
steps that we needed to enable it, using buildroot, of course:

(1) add –msoft-float option in buildroot/make/gcc-3.3.mk for both
initial and final gcc configuration

(2) add –msoft-float at the end of TAGET_LIBGCC2_CFLAGS in
buildroot/toolchain-build-mipsel/gcc-3.3.1/config/t-linux

(3) When you build,
buildroot/build-mipsel/uClibc/extra/scripts/fix-includes.sh is
automatically generated. You need to change line 136 from

            unset –x to unset

 

then continue to build.

I hope this information helps.

-Jeff


On Tue, 2003-09-30 at 12:31, Erik Andersen wrote:
> On Tue Sep 30, 2003 at 07:47:32PM +0100, david stevenson wrote:
> > Eric
> 
> s/Eric/Erik/
> :-)
> 
> > Do you know how to do this?
> > I am now using Thomas's suggestion of using kernel support, but I had tried to 
> > build gcc with soft-float without finding the magic. 2.95.3 has a file 
> > softfloat.c but I could not find the right way to include it.
> 
> I believe the missing soft-float routines are defined in
> <gcc-dir>/gcc/config/fp-bit.[ch]
> 
> I'm guessing that soft-float on x86 probably requires that you
> modify <gcc-dir>/gcc/config/i386/t-i386elf so that it does the
> soft-float stuff, similar to what is done in t-rtems-i386.
> 
> i.e. Making soft-float work on x86 appears to not be supported
> by gcc w/o doing some hacking on the compiler to set that up.
> 
> Clearly the path of least resistance is to use the kernel FPU
> emulator,
> 
>  -Erik
> 
> --
> Erik B. Andersen             http://codepoet-consulting.com/
> --This message was written using 73% post-consumer electrons--
> _______________________________________________
> uClibc mailing list
> uClibc at uclibc.org
> http://uclibc.org/mailman/listinfo/uclibc
-- 
Jeffrey Baitis <baitisj at evolution.com>