[llvm] [VPlan] Mark default value or ExtractLastActive as only first lane used. (PR #226153)

[Florian Hahn via llvm-commits]

================
@@ -1745,6 +1745,8 @@ bool VPInstruction::usesFirstLaneOnly(const VPValue *Op) const {
     return Op == getOperand(1);
   case Instruction::InsertElement:
     return Op == getOperand(1) || Op == getOperand(2);
+  case VPInstruction::ExtractLastActive:
+    return Op == getOperand(0);
----------------
fhahn wrote:

Yeah I see how the name can be confusing. I put up https://github.com/llvm/llvm-project/pull/226494 to adjust the name

https://github.com/llvm/llvm-project/pull/226153