[PATCH] A new HeapToStack allocation promotion pass

[Joey Gouly]

  > FAddr might not be an instruction, but it probably is. I could write:
  >
  > if (isa<Instruction>(FAddr) && VerifiedMallocs.count(cast<Instruction>(FAddr))) or even
  >
  > if (VerifiedMallocs.count(dyn_cast<Instruction>(FAddr)))
  > but both of those pessimize the common case. Pointers to non-instruction will never be in the map.
  >
  > It is just a micro-optimization (which happens to lead to fewer source-code characters). I'm fine with removing it for clarity.

  Does it actually make any noticeable difference?
  I personally prefer the use of dyn_cast, but I won't push too hard for it.

http://llvm-reviews.chandlerc.com/D1745