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

[Dominik Montada via Phabricator via llvm-commits]

gargaroff 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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Should this skip COPYs?


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Comment at: llvm/include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h:639
+      for (MachineInstr &U : MRI.use_instructions(MI.getOperand(0).getReg())) {
+        if (U.getOpcode() == TargetOpcode::G_UNMERGE_VALUES) {
+          UpdatedDefs.push_back(MI.getOperand(0).getReg());
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The artifact combiner can also combine trunc(merge). Could you add trunc users to the worklist as well?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77931/new/

https://reviews.llvm.org/D77931