[PATCH] D15537: limit the number of instructions per block examined by dead store elimination

[Philip Reames via llvm-commits]

FYI, I'm going to defer to Danny on the choice to move forward with this 
patch or an alternate.  I feel he's in the best position to assess the 
overall timeline for MemorySSA.

On 08/23/2016 01:35 PM, Xinliang David Li wrote:
> On Tue, Aug 23, 2016 at 1:20 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
>>> While implementing caching is possible, I think we should avoid
>>> reinventing the wheel in memorySSA, but to keep the fix as simple as
>>> possible.  The new limit can be adjusted higher as its meaning has
>>> changed.
>>
>> I'd be more okay with your last argument if you were going to commit to
>> rewriting this pass to MemorySSA.
>> :)
> Definitely committed -- no question about it :)  I don't think we have
> any choice actually, but patches like this do allow buy us more time
> to do so.
>
>
>> If we have no-one committed to moving the pass, and no plans to implement
>> caching, i guess my answer is "hope that someone will move this to MemorySSA
>> one day is not a strategy".
> that is right.
>
> For this patch, I considered it high priority because there are so
> many people got hit by the same issue again and again. The most recent
> clang hanging problem in building chromium is a recent example.
>
> David
>
>>