[PATCH] D77931: [GlobalISel] Enable artifact combiner to combine starting from a G_MERGE_VALUES

[Amara Emerson via Phabricator via llvm-commits]

aemerson marked an inline comment as done.
aemerson added inline comments.


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Comment at: llvm/include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h:638
+      // artifact worklist in case there's folding that can be done looking up.
+      for (MachineInstr &U : MRI.use_instructions(MI.getOperand(0).getReg())) {
+        if (U.getOpcode() == TargetOpcode::G_UNMERGE_VALUES) {
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gargaroff wrote:
> Should this skip COPYs?
I don't think it's quite that simple. Here we may have multiple users, and if we skip through COPYs then we have to potentially search through a tree rather than just walking up a single chain. This could have a compile time impact.


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  https://reviews.llvm.org/D77931/new/

https://reviews.llvm.org/D77931