[LLVMdev] dominance frontiers

[Chris Lattner]

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