[llvm] [OMPIRBuilder] Don't discard the debug record from entry block. (PR #135161)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-openmp

Author: Abid Qadeer (abidh)

<details>
<summary>Changes</summary>

When we get a function back from `CodeExtractor`, we discard its entry block after coping its instructions into the entry block we prepared. While copying the instructions, the terminator is discarded for obvious reasons. But if there were some debug values attached to the terminator, those are useful and needs to be copied.

---
Full diff: https://github.com/llvm/llvm-project/pull/135161.diff


1 Files Affected:

- (modified) llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp (+6-1) 


``````````diff
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
index 28662efc02882..f946fab42ca7a 100644
--- a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
+++ b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -788,8 +788,13 @@ void OpenMPIRBuilder::finalize(Function *Fn) {
         Instruction &I = *It;
         It++;
 
-        if (I.isTerminator())
+        if (I.isTerminator()) {
+          // Absorb any debug value that terminator may have
+          if (OI.EntryBB->getTerminator())
+            OI.EntryBB->getTerminator()->adoptDbgRecords(
+                &ArtificialEntry, I.getIterator(), false);
           continue;
+        }
 
         I.moveBeforePreserving(*OI.EntryBB, OI.EntryBB->getFirstInsertionPt());
       }

``````````

</details>


https://github.com/llvm/llvm-project/pull/135161