llvm dev - Jan 2009 - [LLVMdev] [llvm-commits] [llvm] r58505 - /llvm/trunk/lib/VMCore/Type.cpp

> 
> From: llvm-commits-bounces at cs.uiuc.edu [mailto:llvm-commits-
> bounces at cs.uiuc.edu] On Behalf Of Chris Lattner
> Sent: Saturday, November 01, 2008 1:49 AM
> To: Commit Messages and Patches for LLVM
> Subject: Re: [llvm-commits] [llvm] r58505 -
> /llvm/trunk/lib/VMCore/Type.cpp
> 
> On Oct 31, 2008, at 3:26 AM, Sanjiv Gupta wrote:
> 
> > Author: sgupta
> > Date: Fri Oct 31 05:26:20 2008
> > New Revision: 58505
> >
> > URL: http://llvm.org/viewvc/llvm-project?rev=58505&view=rev
> > Log:
> > For some targets pointer and int are 16-bits. Allow 16-bits as a
> > valid index
> > in such cases.
> 
> Sanjiv,
> 
> Are you planning to make changes to the bc reader/writer, docs, and
> other parts of the compiler to support this change?  I'd strongly
> prefer to you produce a more holistic patch that makes this change
> instead of a couple individual places.
> 
Hi Chris,

I am starting an old pending task. This is to make 16 bit integer a
valid index.

Above in the mail is the link to modification that Sanjiv made. Also, I
have just gone through an old discussion related to index validity. Here
is the link -
http://lists.cs.uiuc.edu/pipermail/llvmdev/2008-July/015674.html

Can you please provide some pointers to what kind of changes bc
reader/writer or other areas of compiler would require.

Regards
Sachin
> I think this is the right way to go, but I don't want to get stuck
> with half of the change in the tree but it not working 100%.
> 
> -Chris
>

On Jan 13, 2009, at 2:08 AM, Sachin.Punyani at microchip.com
wrote:
> I am starting an old pending task. This is to make 16 bit integer a
> valid index.
Great!
> Above in the mail is the link to modification that Sanjiv made.  
> Also, I
> have just gone through an old discussion related to index validity.  
> Here
> is the link -
> http://lists.cs.uiuc.edu/pipermail/llvmdev/2008-July/015674.html
>
> Can you please provide some pointers to what kind of changes bc
> reader/writer or other areas of compiler would require.
At the minimum, we need to be able to write a GEP with a 16-bit index  
in a .ll file, and do:

llvm-as < foo.ll | llvm-dis | llvm-as | llvm-dis

and get the same gep out.  This means that we need a way to encode the  
index in the .bc file.  Also, the description in docs/LangRef.html and  
the getelementptr FAQ need to be updated.

Thanks for tackling this!

-Chris