[PATCH] D76339: [GlobalISel] Port some basic undef combines from DAGCombiner.cpp

Wed Mar 18 10:52:37 PDT 2020

dsanders accepted this revision.
dsanders added a comment.
This revision is now accepted and ready to land.

I was going to ask you to use the custom predicate feature but it doesn't appear to be there. I could have sworn I'd committed that before I had to temporarily prioritize other work. It doesn't seem to have been committed and reverted without me noticing either. Oh well, LGTM with the all_combine change and I'll migrate it to custom predicates once I've actually landed that.

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Comment at: llvm/test/CodeGen/AArch64/GlobalISel/prelegalizercombiner-undef.mir:3
+# RUN: llc -mtriple aarch64 -run-pass=aarch64-prelegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+...
+---
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It's a little odd to have an empty YAML doc at the start of the file. This line should probably be removed

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https://reviews.llvm.org/D76339