[llvm] [LV] Reduce register pressure of RISC-V outer loop reduction. (PR #208621)

[Florian Hahn via llvm-commits]

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@@ -3770,6 +3783,8 @@ InstructionCost VPExpressionRecipe::computeCost(ElementCount VF,
             Instruction::ZExt,
         Opcode, RedTy, SrcVecTy, Ctx.CostKind);
   }
+  default:
+    llvm_unreachable("Unsupported VPExpressionRecipe::ExpressionTypes enum");
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fhahn wrote:

Do we need this? This will disable warnings for unhandled entries?

https://github.com/llvm/llvm-project/pull/208621