[PATCH] D79100: [LV][TTI] Emit new IR intrinsic llvm.get.active.mask for tail-folded loops

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


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Comment at: llvm/docs/LangRef.rst:16198
+active/inactive vector lanes. This mask can e.g. be used in the masked
+load/store instructions.
+
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Is this semantically equivalent to icmp ule?  If it is, you should probably make that more clear, and explain that it's a hint to the backend.  If not, this needs a much more thorough explanation.


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Comment at: llvm/include/llvm/IR/Intrinsics.td:1240
+  Intrinsic<[llvm_anyvector_ty],
+            [llvm_anyvector_ty, llvm_anyvector_ty], [IntrNoDuplicate]>;
 
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Is IntrNoDuplicate here actually semantically significant?  The LangRef explanation doesn't really indicate why it needs to be noduplicate.

Please use LLVMMatchType/LLVMScalarOrSameVectorWidth to ensure the argument/result types match.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D79100/new/

https://reviews.llvm.org/D79100