[PATCH] D139109: [LoopUnswitch] Perform loop unswitching on select instructions

Mon Apr 10 21:53:16 PDT 2023

caojoshua added a comment.

In D139109#4255024 <https://reviews.llvm.org/D139109#4255024>, @kachkov98 wrote:

> @caojoshua Sure, I prefer your approach without select -> branch convertion more (the weak point here is that unswitching can fail after this conversion, and subsequent passes should fold branch to select back). You can share LIT test if it will be helpful.

Ha, that's funny. I was actually going to say I prefer your approach and would have liked to work on top of this patch. It does not look possible that a select is converted, and then unswitching fails. By the time you convert a select, it has already been determined a legal unswitch target with the best cost.

Repository:
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https://reviews.llvm.org/D139109