2006-11-05 21:16:41

by James Courtier-Dutton

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Subject: i387 Floating Point Unit (FPU) testing

Hi,

The kernel contains some i387 FPU emulation code.
Is there any user land software to test the FPU emulation code?
I would like to be able to prove the correctness of the FPU emulation
code in the Linux kernel, and also port the test program to other
platforms that utilize FPU emulation. For example, DOS emulators like
DOSBOX.

James


2006-11-05 23:36:04

by Jan Engelhardt

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Subject: Re: i387 Floating Point Unit (FPU) testing


> The kernel contains some i387 FPU emulation code.
> Is there any user land software to test the FPU emulation code?
> I would like to be able to prove the correctness of the FPU emulation code in
> the Linux kernel, and also port the test program to other platforms that
> utilize FPU emulation. For example, DOS emulators like DOSBOX.

If the kernel already emulates it, you don't really need emulation in
userspace, no?

-`J'
--

2006-11-06 00:12:35

by James Courtier-Dutton

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Subject: Re: i387 Floating Point Unit (FPU) testing

Jan Engelhardt wrote:
>> The kernel contains some i387 FPU emulation code.
>> Is there any user land software to test the FPU emulation code?
>> I would like to be able to prove the correctness of the FPU emulation code in
>> the Linux kernel, and also port the test program to other platforms that
>> utilize FPU emulation. For example, DOS emulators like DOSBOX.
>
> If the kernel already emulates it, you don't really need emulation in
> userspace, no?
>
> -`J'

Hum...Did you actually read my email?

2006-11-07 01:11:15

by H. Peter Anvin

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Subject: Re: i387 Floating Point Unit (FPU) testing

James Courtier-Dutton wrote:
> Hi,
>
> The kernel contains some i387 FPU emulation code.
> Is there any user land software to test the FPU emulation code?
> I would like to be able to prove the correctness of the FPU emulation
> code in the Linux kernel, and also port the test program to other
> platforms that utilize FPU emulation. For example, DOS emulators like
> DOSBOX.
>

The i387 FPU emulation code is originally from DJGPP, I believe.

-hpa