[PATCH] D132329: [X86][RFC] Using `__bf16` for AVX512_BF16 intrinsics

[Simon Pilgrim via Phabricator via cfe-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:2185
+    addRegisterClass(MVT::v32bf16, &X86::VR512RegClass);
+    setOperationAction(ISD::BUILD_VECTOR, MVT::bf16, Custom);
+    setOperationAction(ISD::BUILD_VECTOR, MVT::v8bf16, Custom);
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pengfei wrote:
> RKSimon wrote:
> > Isn't MVT::bf16 scalar? 
> Yes, when legalize the source operand, the legalizer gets action as the type action, i.e., `TypeSoftPromoteHalf`. However, we don't provide methods to handle any vector actions in soft promote. So we need to set it `Custom` here to do the customization.
OK - please can you add a short comment explaining that


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D132329/new/

https://reviews.llvm.org/D132329