[llvm] [LV] Support binary and unary operations with EVL-vectorization (PR #93854)

[Kolya Panchenko via llvm-commits]

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@@ -1140,6 +1144,53 @@ void VPWidenRecipe::execute(VPTransformState &State) {
 #endif
 }
 
+void VPWidenEVLRecipe::execute(VPTransformState &State) {
+  assert(State.UF == 1 && "Expected only UF == 1 when vectorizing with "
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nikolaypanchenko wrote:

It's only for EVL-vectorization, as for now it's easier not to handle multiple `get.vector.length`, where one or many could return `0`, thus following instructions will process 0 elements. Another worry I have is we will have to emit extra checks for zero EVL if instruction does ignore it, like RISC-V's `vmv.x.s` if it's generated within a loop

https://github.com/llvm/llvm-project/pull/93854