[Qemu-devel] [PATCH] Use proper term in TCG README

[Qemu-devel] [PATCH] Use proper term in TCG README

[陳韋任 (Wei-Ren Chen)]

  In TCG, "target" means the host architecture for which TCG generates the
code. Using "guest" rather than "target" to make the document more consistent.

Signed-off-by: Chen Wei-Ren <chenwj@iis.sinica.edu.tw>
---
 tcg/README | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcg/README b/tcg/README
index 934e7af..22174c0 100644
--- a/tcg/README
+++ b/tcg/README
@@ -379,7 +379,7 @@ double-word product T0.  The later is returned in two single-word outputs.
 
 Similar to mulu2, except the two inputs T1 and T2 are signed.
 
-********* 64-bit target on 32-bit host support
+********* 64-bit guest on 32-bit host support
 
 The following opcodes are internal to TCG.  Thus they are to be implemented by
 32-bit host code generators, but are not to be emitted by guest translators.
-- 
1.7.12.3

Re: [Qemu-devel] [PATCH] Use proper term in TCG README

[Stefan Hajnoczi]

On Thu, Mar 07, 2013 at 11:33:01AM +0800, 陳韋任 (Wei-Ren Chen) wrote:
>   In TCG, "target" means the host architecture for which TCG generates the
> code. Using "guest" rather than "target" to make the document more consistent.
> 
> Signed-off-by: Chen Wei-Ren <chenwj@iis.sinica.edu.tw>
> ---
>  tcg/README | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tcg/README b/tcg/README
> index 934e7af..22174c0 100644
> --- a/tcg/README
> +++ b/tcg/README
> @@ -379,7 +379,7 @@ double-word product T0.  The later is returned in two single-word outputs.
>  
>  Similar to mulu2, except the two inputs T1 and T2 are signed.
>  
> -********* 64-bit target on 32-bit host support
> +********* 64-bit guest on 32-bit host support
>  
>  The following opcodes are internal to TCG.  Thus they are to be implemented by
>  32-bit host code generators, but are not to be emitted by guest translators.

Review from TCG experts please.

It seems we have multiple meanings for "target" (e.g. ./configure
--target-list= does not mean "the host architecture for which TCG
generates code"), if this is really the way TCG uses the term then fine.

Stefan

Re: [Qemu-devel] [PATCH] Use proper term in TCG README

[Peter Maydell]

On 8 March 2013 17:21, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> On Thu, Mar 07, 2013 at 11:33:01AM +0800, 陳韋任 (Wei-Ren Chen) wrote:
>>   In TCG, "target" means the host architecture for which TCG generates the
>> code. Using "guest" rather than "target" to make the document more consistent.

>> @@ -379,7 +379,7 @@ double-word product T0.  The later is returned in two single-word outputs.
>>
>>  Similar to mulu2, except the two inputs T1 and T2 are signed.
>>
>> -********* 64-bit target on 32-bit host support
>> +********* 64-bit guest on 32-bit host support
>>
>>  The following opcodes are internal to TCG.  Thus they are to be implemented by
>>  32-bit host code generators, but are not to be emitted by guest translators.
>
> Review from TCG experts please.
>
> It seems we have multiple meanings for "target" (e.g. ./configure
> --target-list= does not mean "the host architecture for which TCG
> generates code"), if this is really the way TCG uses the term then fine.

Yes, this is an unfortunate terminology clash, but in a TCG context
'target' does mean 'host architecture which the backend compiles for'
(see the tcg/README definition in section 2). This is partly because
of TCG's history as a C compiler backend, where 'target' is unambiguous
and may be different from the 'host' architecture the compiler itself
executes on.

There are several places in tcg/README which use 'target' in the
sense 'QEMU target, ie guest' (as well as lots of uses in the
'TCG target, ie host' sense), not just this one; it might be a good
idea to put a note in the Definitions section that this document uses
'guest' when it means what in other areas of QEMU is often referred to
as the 'target', and fix the places where we've accidentally used 'target'
and 'guest would be better.

-- PMM

Re: [Qemu-devel] [PATCH] Use proper term in TCG README

[Stefan Hajnoczi]

On Fri, Mar 08, 2013 at 05:29:29PM +0800, Peter Maydell wrote:
> On 8 March 2013 17:21, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> > On Thu, Mar 07, 2013 at 11:33:01AM +0800, 陳韋任 (Wei-Ren Chen) wrote:
> >>   In TCG, "target" means the host architecture for which TCG generates the
> >> code. Using "guest" rather than "target" to make the document more consistent.
> 
> >> @@ -379,7 +379,7 @@ double-word product T0.  The later is returned in two single-word outputs.
> >>
> >>  Similar to mulu2, except the two inputs T1 and T2 are signed.
> >>
> >> -********* 64-bit target on 32-bit host support
> >> +********* 64-bit guest on 32-bit host support
> >>
> >>  The following opcodes are internal to TCG.  Thus they are to be implemented by
> >>  32-bit host code generators, but are not to be emitted by guest translators.
> >
> > Review from TCG experts please.
> >
> > It seems we have multiple meanings for "target" (e.g. ./configure
> > --target-list= does not mean "the host architecture for which TCG
> > generates code"), if this is really the way TCG uses the term then fine.
> 
> Yes, this is an unfortunate terminology clash, but in a TCG context
> 'target' does mean 'host architecture which the backend compiles for'
> (see the tcg/README definition in section 2). This is partly because
> of TCG's history as a C compiler backend, where 'target' is unambiguous
> and may be different from the 'host' architecture the compiler itself
> executes on.
> 
> There are several places in tcg/README which use 'target' in the
> sense 'QEMU target, ie guest' (as well as lots of uses in the
> 'TCG target, ie host' sense), not just this one; it might be a good
> idea to put a note in the Definitions section that this document uses
> 'guest' when it means what in other areas of QEMU is often referred to
> as the 'target', and fix the places where we've accidentally used 'target'
> and 'guest would be better.

Wei-Ren, can you please convert the other instances in tcg/README where
'target' is used in the 'guest' sense, too?

Stefan

Re: [Qemu-devel] [PATCH] Use proper term in TCG README

[陳韋任 (Wei-Ren Chen)]

On Fri, Mar 08, 2013 at 11:13:24AM +0100, Stefan Hajnoczi wrote:
> On Fri, Mar 08, 2013 at 05:29:29PM +0800, Peter Maydell wrote:
> > On 8 March 2013 17:21, Stefan Hajnoczi <stefanha@gmail.com> wrote:
> > > On Thu, Mar 07, 2013 at 11:33:01AM +0800, 陳韋任 (Wei-Ren Chen) wrote:
> > >>   In TCG, "target" means the host architecture for which TCG generates the
> > >> code. Using "guest" rather than "target" to make the document more consistent.
> > 
> > >> @@ -379,7 +379,7 @@ double-word product T0.  The later is returned in two single-word outputs.
> > >>
> > >>  Similar to mulu2, except the two inputs T1 and T2 are signed.
> > >>
> > >> -********* 64-bit target on 32-bit host support
> > >> +********* 64-bit guest on 32-bit host support
> > >>
> > >>  The following opcodes are internal to TCG.  Thus they are to be implemented by
> > >>  32-bit host code generators, but are not to be emitted by guest translators.
> > >
> > > Review from TCG experts please.
> > >
> > > It seems we have multiple meanings for "target" (e.g. ./configure
> > > --target-list= does not mean "the host architecture for which TCG
> > > generates code"), if this is really the way TCG uses the term then fine.
> > 
> > Yes, this is an unfortunate terminology clash, but in a TCG context
> > 'target' does mean 'host architecture which the backend compiles for'
> > (see the tcg/README definition in section 2). This is partly because
> > of TCG's history as a C compiler backend, where 'target' is unambiguous
> > and may be different from the 'host' architecture the compiler itself
> > executes on.
> > 
> > There are several places in tcg/README which use 'target' in the
> > sense 'QEMU target, ie guest' (as well as lots of uses in the
> > 'TCG target, ie host' sense), not just this one; it might be a good
> > idea to put a note in the Definitions section that this document uses
> > 'guest' when it means what in other areas of QEMU is often referred to
> > as the 'target', and fix the places where we've accidentally used 'target'
> > and 'guest would be better.
> 
> Wei-Ren, can you please convert the other instances in tcg/README where
> 'target' is used in the 'guest' sense, too?

  I will look into the tcg/README again. :)

Regards,
chenwj 

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj