[llvm-commits] [llvm] r111995 - /llvm/trunk/lib/VMCore/Metadata.cpp

[Dan Gohman]

On Aug 24, 2010, at 4:33 PM, Chris Lattner <clattner at apple.com> wrote:

>
> On Aug 24, 2010, at 4:21 PM, Dan Gohman wrote:
>
>> Author: djg
>> Date: Tue Aug 24 18:21:12 2010
>> New Revision: 111995
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=111995&view=rev
>> Log:
>> Don't include the is-function-local bit in the FoldingSetNodeID
>> for MDNodes, since this information is effectively implied by
>> the operands. This allow allows the code to avoid doing a
>> recursive is-it-really-function-local check in some cases.
>
> One trick with this: if the function local operand of a local md  
> node drops to null, the node stays function local.

When an operand drops to null, we also take the node out of the  
uniquing map.  I'll add some comments about this.

Dan