[PATCH] D82049: Fix crash in VectorCombine when attempting to peephole ConstantVector sequences

Fri Jun 19 09:12:40 PDT 2020

spatel added a comment.

In D82049#2103625 <https://reviews.llvm.org/D82049#2103625>, @nikic wrote:

> Compile-time numbers: https://llvm-compile-time-tracker.com/compare.php?from=35651fdd4537c081ca47acde58b6fd4b5f6997b3&to=5ff2db86f51083878ff9a458a39b355a03b31e73&stat=instructions

Thanks for pre-testing that!

> It should be noted that while InstSimplify is cheap relative to InstCombine, it's likely a good bit more expansive than the actual VectorCombine itself :)

I figured that InstSimplify probably costs more than this pass, but I didn't realize it would be above the noise in a full compile. Good to know.

> As the original patch does not look particularly complicated, I would prefer the more targeted fix.

Ok - let's go back to the 1st draft with the updated test.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D82049/new/

https://reviews.llvm.org/D82049