[llvm] [VP][RISCV] Add llvm.experimental.vp.reverse. (PR #70405)

[Luke Lau via llvm-commits]

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@@ -702,6 +702,12 @@ BEGIN_REGISTER_VP(experimental_vp_splice, 3, 5, EXPERIMENTAL_VP_SPLICE, -1)
 VP_PROPERTY_FUNCTIONAL_INTRINSIC(experimental_vector_splice)
 END_REGISTER_VP(experimental_vp_splice, EXPERIMENTAL_VP_SPLICE)
 
+// llvm.experimental.vp.reverse(x,mask,vlen)
+BEGIN_REGISTER_VP(experimental_vp_reverse, 1, 2,
+                  EXPERIMENTAL_VP_REVERSE, -1)
+VP_PROPERTY_FUNCTIONAL_INTRINSIC(experimental_vector_reverse)
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lukel97 wrote:

The expand vector predication pass will expand out llvm.experimental.vp.reverse to llvm.experimental.vector.reverse and drop the EVL if we mark it as functionally equivalent, but without the EVL it won't be the same reverse. Should this be marked as `VP_PROPERTY_NO_FUNCTIONAL` instead?

https://github.com/llvm/llvm-project/pull/70405