[PATCH] D97609: [RISCV] Add support for VECTOR_REVERSE for scalable vector types.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/utils/TableGen/CodeGenDAGPatterns.cpp:731
 
-  auto NoSize = [](const SmallSet<TypeSize, 2> &Sizes, MVT T) -> bool {
-    return !Sizes.count(T.getSizeInBits());
+  auto NoSize =
+      [](const SmallSet<std::pair<bool, TypeSize::ScalarTy>, 2> &Sizes,
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This hack is to prevent tablegen from throwing a bunch of warnings about assuming a vector type is not scalable. This occurs because of my use of SDTCisSameSizeAs in the type profile for vrgather_vv_vl in tablegen.

SmallSet defaults to std::less as its comparison function. But TypeSize doesn't implement operator< natively. But it appears to match to the operator< for uint64_t since there's a conversion operator to uint64_t in TypeSize. But that only works for fixed vectors.

To workaround this, I explicitly split up the TypeSize into a std::pair. Adding an operator< to TypeSize didn't seem like a good idea. Another option might be to switch to SmallDenseSet and add a DenseMapInfo for TypeSize.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D97609/new/

https://reviews.llvm.org/D97609