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Carter Cheng

2009-Aug-02 23:09 UTC

[LLVMdev] Union type efforts and ComputeLinearIndex

I just looked over your diff and it would seem to me that additional changes
would be needed to be done to some of the LLVM-IR -> DAG stuff to make things
fully functional (this could be a bit of supposition on my part since I do not
fully understand all of the code).


--- On Sun, 8/2/09, Andrew Lenharth <andrewl at lenharth.org> wrote:
> From: Andrew Lenharth <andrewl at lenharth.org>
> Subject: Re: [LLVMdev] Union type efforts and ComputeLinearIndex
> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
> Date: Sunday, August 2, 2009, 3:55 PM
> I posted an initial implementation
> that would generate code correctly,
> though I don't know that all optimization pass were safe
> still.
> 
> see:
> 
>
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090511/077443.html
> 
> As far as I know, there isn't enough demand right now for
> unions.
> They are mainly useful for target-independent
> front-ends.  I don't
> have the time right now to push them, though they would be
> useful for
> my work, just not critical.
> 
> Andrew
> 
> On Sun, Aug 2, 2009 at 3:57 PM, Carter Cheng<carter_cheng at
yahoo.com>
> wrote:
> > Hi,
> >
> > I really dont know I came rather late to the
> discussion and some kind folks on this list gave me a few
> links. I didnt see much mention of any controversy. Are
> there issues still that need to be resolved?
> >
> > So far I am still quite the novice with LLVM internals
> but looking over the code it looks like one could hack in
> most of the required functionality up to the DAG building
> stage. I am not sure if this would work so perhaps I could
> get some opinions.
> >
> > My thoughts were as follows- introduce a new
> CompositeType called union (possibly refactoring some stuff
> into a common parent class from StructType).
> >
> > Recycle GEP (using RTTI) to handle UnionType field
> lookups as well. Add type codes into bitreader/bitwriter
> which would cope with the new union type. Add u { ... } into
> the AsmParser.
> >
> > Revise some of the target classes to cope with the
> unusual data layout and report back correct size for the
> union type. Add support for DAG generation into the
> DAGBuilder visitor class.
> >
> > I am just seeing this UnionType as a type of struct
> where all the fields have the same offset and the UnionType
> itself is as large as the largest member. I would speculate
> that otherwise it behaves pretty much like a StructType- but
> then again I am new to LLVM.
> >
> >
> > --- On Sun, 8/2/09, Dan Gohman <gohman at apple.com>
> wrote:
> >
> >> From: Dan Gohman <gohman at apple.com>
> >> Subject: Re: [LLVMdev] Union type efforts and
> ComputeLinearIndex
> >> To: "LLVM Developers Mailing List" <llvmdev at
cs.uiuc.edu>
> >> Date: Sunday, August 2, 2009, 12:05 PM
> >> Hello,
> >>
> >> My understanding of the discussions about union
> types was
> >> that
> >> there was trouble working out how unions should
> work. Have
> >> the issues been resolved?  If so, could you post
> a
> >> summary?
> >>
> >> Thanks,
> >>
> >> Dan
> >>
> >> On Aug 2, 2009, at 7:45 AM, Carter Cheng wrote:
> >>
> >> > I am curious how the efforts were progressing
> in
> >> implementing a
> >> > union type. I am will to try to contribute
> somewhat to
> >> this even
> >> > though I am perhaps somewhat of a beginner
> with
> >> LLVM(so it might be
> >> > nice to collaborate with someone). I had a
> look at
> >> some of the
> >> > subsystems that would require changes though
> I may
> >> have missed some.
> >> >
> >> > I however have a few questions-
> >> >
> >> > 1) What is ComputeLinearIndex for
> specifically? I
> >> would expect that
> >> > perhaps the RTTI stuff in there might need to
> support
> >> a new case for
> >> > a union type.
> >> >
> >> > 2) The subsystems I have catalogued that
> probably need
> >> patching are
> >> > AsmParser, BitCode(Reader/Writer), Target,
> CodeGen and
> >> some stuff in
> >> > VMCore. Did I miss anything?
> >> >
> >> > Thanks in advance.
> >> >
> >> >
> >> >
> >> >
> _______________________________________________
> >> > LLVM Developers mailing list
> >> > LLVMdev at cs.uiuc.edu
> >>        http://llvm.cs.uiuc.edu
> >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >>
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> LLVMdev at cs.uiuc.edu
> >>        http://llvm.cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >>
> >
> >
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu
>         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu 
>        http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

Andrew Lenharth

2009-Aug-02 23:37 UTC

head link

[LLVMdev] Union type efforts and ComputeLinearIndex

On Sun, Aug 2, 2009 at 6:09 PM, Carter Cheng<carter_cheng at yahoo.com>
wrote:> I just looked over your diff and it would seem to me that additional
changes would be needed to be done to some of the LLVM-IR -> DAG stuff to
make things fully functional (this could be a bit of supposition on my part
since I do not fully understand all of the code).
Code generation actually was supported.

See:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090511/077465.html

Namely, look at the code in target data.

Andrew
>
> --- On Sun, 8/2/09, Andrew Lenharth <andrewl at lenharth.org> wrote:
>
>> From: Andrew Lenharth <andrewl at lenharth.org>
>> Subject: Re: [LLVMdev] Union type efforts and ComputeLinearIndex
>> To: "LLVM Developers Mailing List" <llvmdev at
cs.uiuc.edu>
>> Date: Sunday, August 2, 2009, 3:55 PM
>> I posted an initial implementation
>> that would generate code correctly,
>> though I don't know that all optimization pass were safe
>> still.
>>
>> see:
>>
>>
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090511/077443.html
>>
>> As far as I know, there isn't enough demand right now for
>> unions.
>> They are mainly useful for target-independent
>> front-ends.  I don't
>> have the time right now to push them, though they would be
>> useful for
>> my work, just not critical.
>>
>> Andrew
>>
>> On Sun, Aug 2, 2009 at 3:57 PM, Carter Cheng<carter_cheng at
yahoo.com>
>> wrote:
>> > Hi,
>> >
>> > I really dont know I came rather late to the
>> discussion and some kind folks on this list gave me a few
>> links. I didnt see much mention of any controversy. Are
>> there issues still that need to be resolved?
>> >
>> > So far I am still quite the novice with LLVM internals
>> but looking over the code it looks like one could hack in
>> most of the required functionality up to the DAG building
>> stage. I am not sure if this would work so perhaps I could
>> get some opinions.
>> >
>> > My thoughts were as follows- introduce a new
>> CompositeType called union (possibly refactoring some stuff
>> into a common parent class from StructType).
>> >
>> > Recycle GEP (using RTTI) to handle UnionType field
>> lookups as well. Add type codes into bitreader/bitwriter
>> which would cope with the new union type. Add u { ... } into
>> the AsmParser.
>> >
>> > Revise some of the target classes to cope with the
>> unusual data layout and report back correct size for the
>> union type. Add support for DAG generation into the
>> DAGBuilder visitor class.
>> >
>> > I am just seeing this UnionType as a type of struct
>> where all the fields have the same offset and the UnionType
>> itself is as large as the largest member. I would speculate
>> that otherwise it behaves pretty much like a StructType- but
>> then again I am new to LLVM.
>> >
>> >
>> > --- On Sun, 8/2/09, Dan Gohman <gohman at apple.com>
>> wrote:
>> >
>> >> From: Dan Gohman <gohman at apple.com>
>> >> Subject: Re: [LLVMdev] Union type efforts and
>> ComputeLinearIndex
>> >> To: "LLVM Developers Mailing List" <llvmdev at
cs.uiuc.edu>
>> >> Date: Sunday, August 2, 2009, 12:05 PM
>> >> Hello,
>> >>
>> >> My understanding of the discussions about union
>> types was
>> >> that
>> >> there was trouble working out how unions should
>> work. Have
>> >> the issues been resolved?  If so, could you post
>> a
>> >> summary?
>> >>
>> >> Thanks,
>> >>
>> >> Dan
>> >>
>> >> On Aug 2, 2009, at 7:45 AM, Carter Cheng wrote:
>> >>
>> >> > I am curious how the efforts were progressing
>> in
>> >> implementing a
>> >> > union type. I am will to try to contribute
>> somewhat to
>> >> this even
>> >> > though I am perhaps somewhat of a beginner
>> with
>> >> LLVM(so it might be
>> >> > nice to collaborate with someone). I had a
>> look at
>> >> some of the
>> >> > subsystems that would require changes though
>> I may
>> >> have missed some.
>> >> >
>> >> > I however have a few questions-
>> >> >
>> >> > 1) What is ComputeLinearIndex for
>> specifically? I
>> >> would expect that
>> >> > perhaps the RTTI stuff in there might need to
>> support
>> >> a new case for
>> >> > a union type.
>> >> >
>> >> > 2) The subsystems I have catalogued that
>> probably need
>> >> patching are
>> >> > AsmParser, BitCode(Reader/Writer), Target,
>> CodeGen and
>> >> some stuff in
>> >> > VMCore. Did I miss anything?
>> >> >
>> >> > Thanks in advance.
>> >> >
>> >> >
>> >> >
>> >> >
>> _______________________________________________
>> >> > LLVM Developers mailing list
>> >> > LLVMdev at cs.uiuc.edu
>> >>        http://llvm.cs.uiuc.edu
>> >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >>
>> >> _______________________________________________
>> >> LLVM Developers mailing list
>> >> LLVMdev at cs.uiuc.edu
>> >>        http://llvm.cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >>
>> >
>> >
>> >
>> >
>> > _______________________________________________
>> > LLVM Developers mailing list
>> > LLVMdev at cs.uiuc.edu
>>         http://llvm.cs.uiuc.edu
>> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>> >
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu
>>        http://llvm.cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
>
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

Carter Cheng

2009-Aug-03 02:28 UTC

head link

[LLVMdev] Union type efforts and ComputeLinearIndex

Ah alright you more or less implemented (perhaps with slight differences) what I
was thinking as well.

--- On Sun, 8/2/09, Andrew Lenharth <andrewl at lenharth.org> wrote:
> From: Andrew Lenharth <andrewl at lenharth.org>
> Subject: Re: [LLVMdev] Union type efforts and ComputeLinearIndex
> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
> Date: Sunday, August 2, 2009, 4:37 PM
> On Sun, Aug 2, 2009 at 6:09 PM,
> Carter Cheng<carter_cheng at yahoo.com>
> wrote:
> > I just looked over your diff and it would seem to me
> that additional changes would be needed to be done to some
> of the LLVM-IR -> DAG stuff to make things fully
> functional (this could be a bit of supposition on my part
> since I do not fully understand all of the code).
> 
> Code generation actually was supported.
> 
> See:
>
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090511/077465.html
> 
> Namely, look at the code in target data.
> 
> Andrew
> 
> >
> > --- On Sun, 8/2/09, Andrew Lenharth <andrewl at lenharth.org>
> wrote:
> >
> >> From: Andrew Lenharth <andrewl at lenharth.org>
> >> Subject: Re: [LLVMdev] Union type efforts and
> ComputeLinearIndex
> >> To: "LLVM Developers Mailing List" <llvmdev at
cs.uiuc.edu>
> >> Date: Sunday, August 2, 2009, 3:55 PM
> >> I posted an initial implementation
> >> that would generate code correctly,
> >> though I don't know that all optimization pass
> were safe
> >> still.
> >>
> >> see:
> >>
> >>
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090511/077443.html
> >>
> >> As far as I know, there isn't enough demand right
> now for
> >> unions.
> >> They are mainly useful for target-independent
> >> front-ends.  I don't
> >> have the time right now to push them, though they
> would be
> >> useful for
> >> my work, just not critical.
> >>
> >> Andrew
> >>
> >> On Sun, Aug 2, 2009 at 3:57 PM, Carter Cheng<carter_cheng at
yahoo.com>
> >> wrote:
> >> > Hi,
> >> >
> >> > I really dont know I came rather late to the
> >> discussion and some kind folks on this list gave
> me a few
> >> links. I didnt see much mention of any
> controversy. Are
> >> there issues still that need to be resolved?
> >> >
> >> > So far I am still quite the novice with LLVM
> internals
> >> but looking over the code it looks like one could
> hack in
> >> most of the required functionality up to the DAG
> building
> >> stage. I am not sure if this would work so perhaps
> I could
> >> get some opinions.
> >> >
> >> > My thoughts were as follows- introduce a new
> >> CompositeType called union (possibly refactoring
> some stuff
> >> into a common parent class from StructType).
> >> >
> >> > Recycle GEP (using RTTI) to handle UnionType
> field
> >> lookups as well. Add type codes into
> bitreader/bitwriter
> >> which would cope with the new union type. Add u {
> ... } into
> >> the AsmParser.
> >> >
> >> > Revise some of the target classes to cope
> with the
> >> unusual data layout and report back correct size
> for the
> >> union type. Add support for DAG generation into
> the
> >> DAGBuilder visitor class.
> >> >
> >> > I am just seeing this UnionType as a type of
> struct
> >> where all the fields have the same offset and the
> UnionType
> >> itself is as large as the largest member. I would
> speculate
> >> that otherwise it behaves pretty much like a
> StructType- but
> >> then again I am new to LLVM.
> >> >
> >> >
> >> > --- On Sun, 8/2/09, Dan Gohman <gohman at apple.com>
> >> wrote:
> >> >
> >> >> From: Dan Gohman <gohman at apple.com>
> >> >> Subject: Re: [LLVMdev] Union type efforts
> and
> >> ComputeLinearIndex
> >> >> To: "LLVM Developers Mailing List" <llvmdev
at cs.uiuc.edu>
> >> >> Date: Sunday, August 2, 2009, 12:05 PM
> >> >> Hello,
> >> >>
> >> >> My understanding of the discussions about
> union
> >> types was
> >> >> that
> >> >> there was trouble working out how unions
> should
> >> work. Have
> >> >> the issues been resolved?  If so, could
> you post
> >> a
> >> >> summary?
> >> >>
> >> >> Thanks,
> >> >>
> >> >> Dan
> >> >>
> >> >> On Aug 2, 2009, at 7:45 AM, Carter Cheng
> wrote:
> >> >>
> >> >> > I am curious how the efforts were
> progressing
> >> in
> >> >> implementing a
> >> >> > union type. I am will to try to
> contribute
> >> somewhat to
> >> >> this even
> >> >> > though I am perhaps somewhat of a
> beginner
> >> with
> >> >> LLVM(so it might be
> >> >> > nice to collaborate with someone). I
> had a
> >> look at
> >> >> some of the
> >> >> > subsystems that would require
> changes though
> >> I may
> >> >> have missed some.
> >> >> >
> >> >> > I however have a few questions-
> >> >> >
> >> >> > 1) What is ComputeLinearIndex for
> >> specifically? I
> >> >> would expect that
> >> >> > perhaps the RTTI stuff in there
> might need to
> >> support
> >> >> a new case for
> >> >> > a union type.
> >> >> >
> >> >> > 2) The subsystems I have catalogued
> that
> >> probably need
> >> >> patching are
> >> >> > AsmParser, BitCode(Reader/Writer),
> Target,
> >> CodeGen and
> >> >> some stuff in
> >> >> > VMCore. Did I miss anything?
> >> >> >
> >> >> > Thanks in advance.
> >> >> >
> >> >> >
> >> >> >
> >> >> >
> >> _______________________________________________
> >> >> > LLVM Developers mailing list
> >> >> > LLVMdev at cs.uiuc.edu
> >> >>        http://llvm.cs.uiuc.edu
> >> >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >> >>
> >> >>
> _______________________________________________
> >> >> LLVM Developers mailing list
> >> >> LLVMdev at cs.uiuc.edu
> >> >>        http://llvm.cs.uiuc.edu
> >> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >> >>
> >> >
> >> >
> >> >
> >> >
> >> >
> _______________________________________________
> >> > LLVM Developers mailing list
> >> > LLVMdev at cs.uiuc.edu
> >>         http://llvm.cs.uiuc.edu
> >> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >> >
> >>
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> LLVMdev at cs.uiuc.edu
> >>        http://llvm.cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >>
> >
> >
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu
>         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >
> 
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu 
>        http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

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