[BranchFolding] Follow up #149999 crash fix

fbf6271c7da20356d7b34583b3711b4126ca1dbb introduced an assertion failure as
setDebugValueUndef was called on DBG_LABELs, which isn't allowed and doesn't
make sense. Fix by skipping the call for DBG_LABELs and hoisting, in line with
the original behaviour.

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index a7c99b1..dcfd9aa 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -2103,8 +2103,9 @@ bool BranchFolder::HoistCommonCodeInSuccs(MachineBasicBlock *MBB) {
         DI->eraseFromParent();
         return;
       }
-
-      DI->setDebugValueUndef();
+      // Move DBG_LABELs without modifying them. Set DBG_VALUEs undef.
+      if (!DI->isDebugLabel())
+        DI->setDebugValueUndef();
       DI->moveBefore(&*Loc);
     };