[Qemu-devel] targets that still use dyngen

[Qemu-devel] targets that still use dyngen

[C.W. Betts]

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What targets still use dyngen?  According to the current source tree,  
Alpha, CRIS PowerPC, and SH4 are still using dyngen; they have an op.c  
file in their target- directory:
ls */op.c
target-alpha/op.c	target-cris/op.c	target-ppc/op.c		target-sh4/op.c
I know nothing about architecture design, so I don't know how much  
effort would be needed to get the rest of these targets to use TCG.  I  
know somebody here (malc) has helped make the TCG backends for  
PowerPC, and surely the work for the front-end wouldn't be that much  
harder (I say naively).  Also, is anyone doing work porting these to  
TCG that we don't know about?

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Re: [Qemu-devel] targets that still use dyngen

[Laurent Desnogues]

On Tue, Jul 29, 2008 at 3:58 AM, C.W. Betts <computers57@hotmail.com> wrote:
> What targets still use dyngen?  According to the current source tree, Alpha,
> CRIS PowerPC, and SH4 are still using dyngen; they have an op.c file in
> their target- directory:
> ls */op.c
> target-alpha/op.c       target-cris/op.c        target-ppc/op.c
> target-sh4/op.c

CRIS has been converted to TCG.  I guess the op.c file is a left-over.

> I know nothing about architecture design, so I don't know how much effort
> would be needed to get the rest of these targets to use TCG.  I know
> somebody here (malc) has helped make the TCG backends for PowerPC, and
> surely the work for the front-end wouldn't be that much harder (I say
> naively).  Also, is anyone doing work porting these to TCG that we don't
> know about?

According to the maintainer list, Jocelyn Mayer is the owner of the
Alpha and PPC targets.  You could perhaps try to ask him
directly.


Laurent

Re: [Qemu-devel] targets that still use dyngen

[malc]

On Mon, 28 Jul 2008, C.W. Betts wrote:

> What targets still use dyngen?  According to the current source tree, Alpha, 
> CRIS PowerPC, and SH4 are still using dyngen; they have an op.c file in their 
> target- directory:
> ls */op.c
> target-alpha/op.c	target-cris/op.c	target-ppc/op.c 
> target-sh4/op.c

> I know nothing about architecture design, so I don't know how much
> effort would be needed to get the rest of these targets to use TCG.
> I know somebody here (malc) has helped make the TCG backends for
> PowerPC, and surely the work for the front-end wouldn't be that much
> harder (I say naively).  Also, is anyone doing work porting these to
> TCG that we don't know about?

It is harder, also much more tedious and requiring intimate knowlege of
underlying architecture.

-- 
mailto:av1474@comtv.ru

Re: [Qemu-devel] targets that still use dyngen

[Laurent Desnogues]

On Tue, Jul 29, 2008 at 10:11 PM, malc <av1474@comtv.ru> wrote:
> It is harder, also much more tedious and requiring intimate knowlege of
> underlying architecture.

I would have thought that Alpha is of similar complexity as MIPS,
that is less than SPARC, x86 or ARM.  Or did you mean that
writing a front-end is harder than a TCG target?


Laurent

Re: [Qemu-devel] targets that still use dyngen

[malc]

On Tue, 29 Jul 2008, Laurent Desnogues wrote:

> On Tue, Jul 29, 2008 at 10:11 PM, malc <av1474@comtv.ru> wrote:
>> It is harder, also much more tedious and requiring intimate knowlege of
>> underlying architecture.
>
> I would have thought that Alpha is of similar complexity as MIPS,
> that is less than SPARC, x86 or ARM.  Or did you mean that
> writing a front-end is harder than a TCG target?

Yes the latter.

-- 
mailto:av1474@comtv.ru

Re: [Qemu-devel] targets that still use dyngen

[J. Mayer]

On Wed, 2008-07-30 at 00:11 +0400, malc wrote:
> On Mon, 28 Jul 2008, C.W. Betts wrote:
> 
> > What targets still use dyngen?  According to the current source tree, Alpha, 
> > CRIS PowerPC, and SH4 are still using dyngen; they have an op.c file in their 
> > target- directory:
> > ls */op.c
> > target-alpha/op.c	target-cris/op.c	target-ppc/op.c 
> > target-sh4/op.c
> 
> > I know nothing about architecture design, so I don't know how much
> > effort would be needed to get the rest of these targets to use TCG.
> > I know somebody here (malc) has helped make the TCG backends for
> > PowerPC, and surely the work for the front-end wouldn't be that much
> > harder (I say naively).  Also, is anyone doing work porting these to
> > TCG that we don't know about?
> 
> It is harder, also much more tedious and requiring intimate knowlege of
> underlying architecture.

I haved planned to port Alpha and PowerPC to tgc, but got no time /
running reference hardware to do it properly at this time. I suppose I
would start with Alpha, which is a very simple target, as a training
before starting porting PowerPC. And before starting working on PowerPC,
I have to isolate and fix various regressions that have been committed
during the last monthes (but still I need to have my PowerPC references
platforms running to be able to validate the fixes).

Talking about Alpha, I would greatly like someone who actually has
knowledge of this platform to go on developping it, as I got no hardware
to compare with and validate the emulation. If anyone feels like working
on it, at least try to compare Qemu behavior with actual hardware and
report bugs....

Regards.

-- 
J. Mayer <l_indien@magic.fr>
Never organized