[llvm] [IVDescriptors] Fix the message of llvm_unreachable. nfc (PR #168509)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Mel Chen (Mel-Chen)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/168509.diff


1 Files Affected:

- (modified) llvm/lib/Analysis/IVDescriptors.cpp (+1) 


``````````diff
diff --git a/llvm/lib/Analysis/IVDescriptors.cpp b/llvm/lib/Analysis/IVDescriptors.cpp
index 641850b46bbd8..30d14b56ed82b 100644
--- a/llvm/lib/Analysis/IVDescriptors.cpp
+++ b/llvm/lib/Analysis/IVDescriptors.cpp
@@ -1250,6 +1250,7 @@ unsigned RecurrenceDescriptor::getOpcode(RecurKind Kind) {
   case RecurKind::FindLastIVUMax:
     // TODO: Set AnyOf and FindIV to Instruction::Select once in-loop reductions
     // are supported.
+    llvm_unreachable("AnyOf and FindIV do not support in-loop");
   default:
     llvm_unreachable("Unknown recurrence operation");
   }

``````````

</details>


https://github.com/llvm/llvm-project/pull/168509