[llvm] [VPlan] Encode single-scalar-ness of VPInstruction in a field (NFC). (PR #227761)

[Ramkumar Ramachandra via llvm-commits]

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@@ -605,15 +605,36 @@ Type *VPReplicateRecipe::computeScalarType(const Instruction *I,
   return computeScalarTypeForInstruction(Opcode, Operands);
 }
 
+/// Returns true if VPInstructions with \p Opcode always produce a single
+/// scalar.
+static bool isAlwaysSingleScalar(unsigned Opcode) {
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artagnon wrote:

I think we want alwaysGeneratesSingleScalar here, and include vector-to-scalar, and the previous single-scalar here?

https://github.com/llvm/llvm-project/pull/227761