DOS ain't dead

On 21 August 2008 Charles Sandmann wrote in comp.os.msdos.djgpp:

A release candidate for CWSDPMI r5 update 2008 is available from:

http://clio.rice.edu/djgpp/csdpmi5b_u.zip

This release contains bug fixes previous released in 2002 (in Symantec
Ghost, and by request) - and SSE support. This is mostly a compile
and release - almost no testing. Based on testing over the next several
weeks, this may become the new official r5 distribution.

Unless you are trying to use SSE you probably won't notice a difference.

Please drop me a note if you find some horrible new bug that should
prevent release.

Thanks.

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THX. I'm not going to do anythiong with sse but some bugfixes always welcomed.

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> THX. I'm not going to do anythiong with sse but some bugfixes always
> welcomed.

It's the same bugfixes as r5 2002, AFAICT (which no one ever uses, they always stubbornly use r5 2000, dunno why).

BTW, FreeBASIC now has "-fpu sse", so it's not as rare as you think. Even GCC does (or will eventually do better) produce SSE output.

> > THX. I'm not going to do anythiong with sse but some bugfixes always
> > welcomed.
>
> It's the same bugfixes as r5 2002, AFAICT (which no one ever uses, they
> always stubbornly use r5 2000, dunno why).
>
> BTW, FreeBASIC now has "-fpu sse", so it's not as rare as you think. Even
> GCC does (or will eventually do better) produce SSE output.

FPC has something similar for years.

Also mmx/SSE use in the move (memcpy) procedure can matter. (see Delphi fastcode project, they have a nice excel sheet with benchmarking different implementations)

> > BTW, FreeBASIC now has "-fpu sse", so it's not as rare as you think.
> Even
> > GCC does (or will eventually do better) produce SSE output.
>
> FPC has something similar for years.

Even in DOS? Be sure to tell them to update their CWSDPMI. And even r6 may have a refresh eventually.

> > FPC has something similar for years.
>
> Even in DOS?

x86 assembler is not different in DOS. And since we have an own assembler for x86,x86_64, so we are not bothered by waiting till sb added the instructions to AS. It's all ortoghonal.

See {$fputype sse2} in the docs.

> > > FPC has something similar for years.
> >
> > Even in DOS?
>
> x86 assembler is not different in DOS. And since we have an own assembler
> for x86,x86_64, so we are not bothered by waiting till sb added the
> instructions to AS. It's all ortoghonal.
>
> See {$fputype sse2} in the docs.

Good to know. But GAS does of course support SSE2 (and more) now. What I meant was you can't use it unless the OS turns on the OSFXSR bit (and turns off EM). And FPC/DOS uses CWSDPMI, ring 3 version, so you can't do it yourself (unless you know how to workaround that ... there is supposedly a way, but it's undocumented and I dunno how).

> FPC/DOS uses CWSDPMI, ring 3 version, so you can't do
> it yourself (unless you know how to workaround that ... there is
> supposedly a way, but it's undocumented and I dunno how

GDT and IDT are your friends when dealing with Ring0

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