[DebugInfo][Inline] Propagate source locs when simplifying cond branches (#134827)

During inlining, we may opportunistically simplify conditional branches
(incl. switches) to unconditional branches if, after inlining, their
destination is fixed. While we do this, we should propagate any
DILocation attached to the original branch to the simplified branch,
which this patch enables.

Found using https://github.com/llvm/llvm-project/pull/107279.

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 9387797..3555064 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -607,7 +607,9 @@ void PruningFunctionCloner::CloneBlock(
       // Constant fold to uncond branch!
       if (Cond) {
         BasicBlock *Dest = BI->getSuccessor(!Cond->getZExtValue());
-        VMap[OldTI] = BranchInst::Create(Dest, NewBB);
+        auto *NewBI = BranchInst::Create(Dest, NewBB);
+        NewBI->setDebugLoc(BI->getDebugLoc());
+        VMap[OldTI] = NewBI;
         ToClone.push_back(Dest);
         TerminatorDone = true;
       }
@@ -622,7 +624,9 @@ void PruningFunctionCloner::CloneBlock(
     if (Cond) { // Constant fold to uncond branch!
       SwitchInst::ConstCaseHandle Case = *SI->findCaseValue(Cond);
       BasicBlock *Dest = const_cast<BasicBlock *>(Case.getCaseSuccessor());
-      VMap[OldTI] = BranchInst::Create(Dest, NewBB);
+      auto *NewBI = BranchInst::Create(Dest, NewBB);
+      NewBI->setDebugLoc(SI->getDebugLoc());
+      VMap[OldTI] = NewBI;
       ToClone.push_back(Dest);
       TerminatorDone = true;
     }