[PATCH] Allow CodeGen to take advantage of functions that always return arguments

[Evan Cheng]

On Apr 19, 2013, at 4:53 PM, Bill Wendling <wendling at apple.com> wrote:

> On Apr 19, 2013, at 7:48 AM, Stephen Lin <swlin at post.harvard.edu> wrote:
> 
>>> OK, I removed some extraneous changes and updated the patch to be
>>> based against a mostly non-recursive implementation of sameNoopInput:
>>> 
>>>   http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130415/172039.html
>>> 
>>> I've also added the restriction that 'returned' can only be on one
>>> parameter to allow sameNoopInput to see through 'returned' without
>>> recursion or extra bookkeeping. There's a minor tack-on bug fix;
>>> apparently the verifier check that 'nest' is only on one parameter was
>>> never working correctly...I'm willing to split that off to a separate
>>> patch if that's preferable though.
>>> 
>>> The other patch listed is my original e-mail has been committed so is
>>> no longer an uncommitted dependency.
>>> 
>>> Stephen
>> 
>> I fixed a small issue (an extraneous recursive call) and rebased against:
>> 
>>    http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130415/172067.html
>> 
>> (although the patch should merge cleanly against the previous version, too.)
>> 
> 
> Hi Stephen,
> 
> The IR part of the patch looks okay to me.
> 
> Evan, Are you okay with the CodeGen changes?

LGTM
> 
> -bw
>