[LLVMdev] dominance frontiers
Chris Lattner
clattner at apple.com
Fri Jan 6 17:17:30 PST 2012
On Jan 6, 2012, at 5:08 PM, Chris Lattner wrote:
>>>
>>> It's very like SSA construction, but must make provision
>>> testing anti dependences. I had planned to use dominance frontiers to
>>> guide placement of phi nodes, as usual.
>>
>> Ok, in that case, please check out include/llvm/Transforms/Utils/SSAUpdater.h,
>> which is the preferred API (that doesn't use dom frontiers) to build SSA.
>
> What approach does it use? I look at the code, but don't really see
> an explanation.
Sorry, my reading comprehension skills were low, I thought you were asking about MemDep for some reason. SSAUpdater uses simple local scans across the CFG, excelling at local updates of values.
-Chris
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