[PATCH] D17433: [ARM] fix initialization of PredictableSelectIsExpensive; NFC

[Sanjay Patel via llvm-commits]

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In http://reviews.llvm.org/D17433#357676, @flyingforyou wrote:

> After reading this, I realized that there is no target description file for CortexA15. So, `isLikeA9() `can't be changed to `isOutOfOrder()`.


I think it's ok that there's no sched model for A15 because:
// FIXME: A15 has currently the same Schedule model as A9.

But it's also true that:
// FIXME: A12 has currently the same Schedule model as A9
// FIXME: A17 has currently the same Schedule model as A9

So isLikeA9() is a *subset* of isOutOfOrder(). Therefore, the reason I said that this change would not be 'no functional change' is because A12 and A17 would now have 'PredictableSelectIsExpensive'. If A12 and A17 are in fact OoO designs, this is probably what we want.

This is the problem with having codegen predicates based on micro-arch models rather than features ("isLikeA9"); they tend to drift in meaning as newer designs are added. I've been trying to remove all of those in the x86 backend.


http://reviews.llvm.org/D17433