[uClibc] 386 floating point

[Jeffrey Baitis]

I'm sorry, I worded my first paragraph very poorly.

What I meant to say is that the Algorithmics kernel emulation is 5x
slower than soft-float support. In order to enable the soft-float
support, perform the following steps...

Oops!

-JB

On Tue, 2003-09-30 at 14:23, Jeffrey Baitis wrote:
> 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--
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-- 
Jeffrey Baitis <baitisj at evolution.com>