[PATCH] D90233: [AArch64] Use DUP for BUILD_VECTOR with few different elements.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


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Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:9157
+      !isConstant && NumDifferentLanes >= 1 &&
+      NumDifferentLanes < ((NumElts - NumUndefLanes) / 2) && NumElts >= 4 &&
+      NumDifferentLanes >= NumConstantLanes;
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I think `NumElts >= 4` is redundant?  If NumElts == 2, there is no value of NumDifferentLanes that makes this pass.


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Comment at: llvm/test/CodeGen/AArch64/arm64-vector-insertion.ll:41
+; CHECK-NEXT:   mov.s v0[3], v1[0]
 ; CHECK-NEXT:   ret
 ;
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The test coverage here seems a bit lacking.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D90233/new/

https://reviews.llvm.org/D90233