software floating point

software floating point

[ÁֹαÔ]

I have some questions...about soft-floating point...

I use MPC860, and I made cross develop enviroment.
Host is i386 machine. Target is MPC860.

package that I use
1. binutils-2.10
2. gcc-2.95.2
3. glibc-2.1.3 (add-ons : glibc-crypt-2.1, glibc-linuxthreads-2.1.3)

I did following steps..
First, I compile the binutils for powerpc cpu.
Second, I build cross compiler with gcc.
Third, I compile glibc for powerpc with cross compiler that I made.
Last, I re-build cross compiler include glibc for library.

When compile third step, shoud I use some options to support software floating point?
or shoud I edit some code to support software floating point?

To support software floating point, which steps should I use some special options in above steps and what option is it need?

Thank u for reading my terrible english...^ ^
Take care...


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Re: software floating point

[Graham Stoney]

=?iso-8859-1?B?wda5zrHU?= writes:
> I have some questions...about soft-floating point...

I suggest you read the section in the HOWTO on the subject, at:
    http://members.xoom.com/greyhams/linux/PowerPC-Embedded-HOWTO-13.html

> When compile third step, shoud I use some options to support software floating point?

You need to configure the compiler to make -msoft-float the default in step 2,
and apply the glibc patch to make it work correctly on the 860 before you do
step 3.

> To support software floating point, which steps should I use some special options in above steps and what option is it need?

The options are mentioned in the HOWTO.

Regards,
Graham
--
Graham Stoney
Principal Hardware/Software Engineer
Canon Information Systems Research Australia
Ph: +61 2 9805 2909  Fax: +61 2 9805 2929

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Software floating point

[Chien-Lung Wu]

Hi,

I am building a cross-compiler for mips-linux on my linux box.  
Everything seems fine,  except software floating point. 
How can I turn on the software floating point when I build the glibc? 
Is software floating point are supported in libm.a/libm.so or ant other
lib*?

Thanks for your help.

Chien-Lung

Re: Software floating point

[Ralf Baechle]

On Wed, Feb 05, 2003 at 06:21:34PM -0500, Chien-Lung Wu wrote:

> I am building a cross-compiler for mips-linux on my linux box.  
> Everything seems fine,  except software floating point. 
> How can I turn on the software floating point when I build the glibc? 
> Is software floating point are supported in libm.a/libm.so or ant other
> lib*?

The kernel includes a floating point emulator so your hard fp code will
run fine on fpu-less code.

  Ralf