[LLVMdev] Proposal for ""llvm.mem.vectorize.safelen"

Robison, Arch
Wed, 20 Aug 2014 15:17:01 -0000

Now that I'm looking at editing LangRef, I have a question.  The current
llvm.loop.vectorize metadata are hints, and have this constraint:

   The``llvm.loop.vectorize`` and ``llvm.loop.interleave`` metadata are only
   optimization hints and the optimizer will only interleave and vectorize loops
   if it believes it is safe to do so.

But safelen is different.  It's an assertion about safety, so prefixing it
with
llvm.loop.vectorize seems inappropriate.  Does is sound reasonable to drop
the "vectorize" portion.  Maybe spell it something like this?

	llvm.loop.carried_dependence_distance.min

- Arch