[llvm-commits] [llvm] r130894 - /llvm/trunk/lib/Transforms/Utils/LCSSA.cpp

[Chris Lattner]

On May 5, 2011, at 9:31 AM, Devang Patel wrote:

> 
> On May 4, 2011, at 5:57 PM, Chris Lattner wrote:
> 
>> 
>> On May 4, 2011, at 4:58 PM, Devang Patel wrote:
>> 
>>> Author: dpatel
>>> Date: Wed May  4 18:58:22 2011
>>> New Revision: 130894
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=130894&view=rev
>>> Log:
>>> Set debug location for new PHI nodes created in exit block. 
>> 
>> Devang,
>> 
>> What does a debug loc even mean for a PHI node?  Conceptually a phi node is a copy in each of the predecessors, certainly it can't have a single debug loc?
>> 
> 
> True, but the copy needs a location. Do you have any thoughts on better alternative?

Why does the copy need a location?  When it gets lowered to a machineinstr, why not use the location of whatever is before it in the block?

-Chris