[PATCH] D105935: WIP: [AArch64][GlobalISel] Legalize bswap <2 x i16>

[Jessica Paquette via Phabricator via llvm-commits]

paquette added inline comments.


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Comment at: llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp:1017
+  auto Copy = MIRBuilder.buildBitcast(v8s8, Insert);
+  auto Rev32 = MIRBuilder.buildInstr(AArch64::REV32v8i8, {v8s8}, {Copy});
+  constrainSelectedInstRegOperands(*Rev32, *ST->getInstrInfo(),
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Can you use G_REV32 here instead? (see: AArch64InstrGISel.td)

I think it's preferable to keep the results of legalization as generic as possible.




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Comment at: llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp:1022
+  auto Bitcast3 = MIRBuilder.buildBitcast(v2s32, Rev32);
+  auto UShr = MIRBuilder.buildInstr(AArch64::USHRv2i32_shift, {v2s32},
+                                    {Bitcast3, 16ULL});
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Is it possible to use a generic instruction here?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D105935/new/

https://reviews.llvm.org/D105935