[PATCH] D99449: [GlobalISel] Implement lowering for G_ROTR and G_ROTL.

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:5372-5374
+  unsigned RevRot = IsLeft ? TargetOpcode::G_ROTR : TargetOpcode::G_ROTL;
+  if (LI.isLegalOrCustom({RevRot, {DstTy, SrcTy}}) &&
+      isPowerOf2_32(EltSizeInBits)) {
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I believe alternate lowerings based on instruction legality should be split into separate lower* functions. That way custom lowering can pick the strategy itself, and the default function would then use these crude legality heuristics to pick which strategy to use.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D99449/new/

https://reviews.llvm.org/D99449