[PATCH] D91655: [AArch64][GlobalISel] Fix crash during legalization of a vector G_SELECT with scalar mask.

[Amara Emerson via Phabricator via llvm-commits]

aemerson added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:6226
+      MaskElt = MIRBuilder.buildSExt(DstTy.getElementType(), MaskElt).getReg(0);
+    // Generate a vector splat idiom to be pattern matched later.
+    auto UndefVec = MIRBuilder.buildUndef(DstTy);
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arsenm wrote:
> Maybe should have a buildSplat helper too
We already have a `MachineIRBuilder::buildSplatVector()` but that just currently emits a G_BUILD_VECTOR with identical elements. Should we change that to settle on the insert_vector_elt & shufflevector idiom as the default representation?


Repository:
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  https://reviews.llvm.org/D91655/new/

https://reviews.llvm.org/D91655