[PATCH] D147266: [AArch64] Add IR intrinsics for vbsl* C intrinsics

Tue May 2 09:29:17 PDT 2023

dmgreen added a comment.

My preference would be for fixing the code we have, not introducing new intrinsics. Intrinsics act as black-boxes for the optimizer, and I'm pretty sure I've heard of cases in the past of the compiler optimizing the or/and/xor's to nicer sequences of instructions. It would be a shame to lose that.

The number of instructions in bsl is quite high compared to many intrinsics, they probably have a high chance of going wrong. But if we know of ways to optimize them (through shouldSinkOperands), then that would be my preference. It can end up helping all cases, not just the intrinsics.

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  https://reviews.llvm.org/D147266/new/

https://reviews.llvm.org/D147266