[PATCH] D88191: [AArch64][GlobalISel] Use custom legalization for G_TRUNC for v8i8 vectors

[Amara Emerson via Phabricator via llvm-commits]

aemerson added inline comments.


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Comment at: llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp:722-727
+  // Similar to how operand splitting is done in SelectiondDAG, we can handle
+  // %res(v8s8) = G_TRUNC %in(v8s32) by generating:
+  //   %inlo(<4x s32>), %inhi(<4 x s32>) = G_UNMERGE %in(<8 x s32>)
+  //   %lo16(<4 x s16>) = G_TRUNC %inlo
+  //   %hi16(<4 x s16>) = G_TRUNC %inhi
+  //   %in16(<8 x s16>) = G_CONCAT_VECTORS %lo16, %hi16
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arsenm wrote:
> I don't think there's anything really custom here
Do you have a suggestion of where this could live? narrowScalar?


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  https://reviews.llvm.org/D88191/new/

https://reviews.llvm.org/D88191