3 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index d898b1796b6..cbb9c1bc00b 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -1780,6 +1780,7 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) {
     // regions, and so we need a conservative combination of the noalias
     // scopes.
     static const unsigned KnownIDs[] = {
+      LLVMContext::MD_dbg,
       LLVMContext::MD_tbaa,
       LLVMContext::MD_alias_scope,
       LLVMContext::MD_noalias,
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 3c2a498669e..85335a21a4b 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -743,6 +743,7 @@ bool MemCpyOpt::performCallSlotOptzn(Instruction *cpy,
   // FIXME: MD_tbaa_struct and MD_mem_parallel_loop_access should also be
   // handled here, but combineMetadata doesn't support them yet
   unsigned KnownIDs[] = {
+    LLVMContext::MD_dbg,
     LLVMContext::MD_tbaa,
     LLVMContext::MD_alias_scope,
     LLVMContext::MD_noalias,
diff --git a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
index 6a094b2a7a1..7feb0cd1df6 100644
--- a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
+++ b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
@@ -293,7 +293,7 @@ void MergedLoadStoreMotion::hoistInstruction(BasicBlock *BB,
 
   // Intersect optional metadata.
   HoistCand->intersectOptionalDataWith(ElseInst);
-  HoistCand->dropUnknownMetadata();
+  HoistCand->dropUnknownMetadata(LLVMContext::MD_dbg);
 
   // Prepend point for instruction insert
   Instruction *HoistPt = BB->getTerminator();
@@ -472,7 +472,7 @@ bool MergedLoadStoreMotion::sinkStore(BasicBlock *BB, StoreInst *S0,
     BasicBlock::iterator InsertPt = BB->getFirstInsertionPt();
     // Intersect optional metadata.
     S0->intersectOptionalDataWith(S1);
-    S0->dropUnknownMetadata();
+    S0->dropUnknownMetadata(LLVMContext::MD_dbg);
 
     // Create the new store to be inserted at the join point.
     StoreInst *SNew = (StoreInst *)(S0->clone());