Rename Instruction::dropUnknownMetadata() to dropUnknownNonDebugMetadata()

and make it always preserve debug locations, since all callers wanted this
behavior anyway.

This is addressing a post-commit review feedback for r245589.

NFC (inside the LLVM tree).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245622 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/Instruction.h

@@ -204,20 +204,22 @@ public:
   void setMetadata(unsigned KindID, MDNode *Node);
   void setMetadata(StringRef Kind, MDNode *Node);
 
-  /// \brief Drop unknown metadata.
+  /// Drop all unknown metadata except for debug locations.
+  /// @{
   /// Passes are required to drop metadata they don't understand. This is a
   /// convenience method for passes to do so.
-  void dropUnknownMetadata(ArrayRef<unsigned> KnownIDs);
-  void dropUnknownMetadata() {
-    return dropUnknownMetadata(None);
+  void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs);
+  void dropUnknownNonDebugMetadata() {
+    return dropUnknownNonDebugMetadata(None);
   }
-  void dropUnknownMetadata(unsigned ID1) {
-    return dropUnknownMetadata(makeArrayRef(ID1));
+  void dropUnknownNonDebugMetadata(unsigned ID1) {
+    return dropUnknownNonDebugMetadata(makeArrayRef(ID1));
   }
-  void dropUnknownMetadata(unsigned ID1, unsigned ID2) {
+  void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) {
     unsigned IDs[] = {ID1, ID2};
-    return dropUnknownMetadata(IDs);
+    return dropUnknownNonDebugMetadata(IDs);
   }
+  /// @}
 
   /// setAAMetadata - Sets the metadata on this instruction from the
   /// AAMDNodes structure.

lib/IR/Metadata.cpp

@@ -1057,14 +1057,10 @@ MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
   return getMetadataImpl(getContext().getMDKindID(Kind));
 }
 
-void Instruction::dropUnknownMetadata(ArrayRef<unsigned> KnownIDs) {
+void Instruction::dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs) {
   SmallSet<unsigned, 5> KnownSet;
   KnownSet.insert(KnownIDs.begin(), KnownIDs.end());
 
-  // Drop debug if needed
-  if (!KnownSet.erase(LLVMContext::MD_dbg))
-    DbgLoc = DebugLoc();
-
   if (!hasMetadataHashEntry())
     return; // Nothing to remove!
 

lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp

@@ -754,7 +754,6 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
                                                      6, AA, &AATags)) {
     if (LoadInst *NLI = dyn_cast<LoadInst>(AvailableVal)) {
       unsigned KnownIDs[] = {
-        LLVMContext::MD_dbg,
         LLVMContext::MD_tbaa,
         LLVMContext::MD_alias_scope,
         LLVMContext::MD_noalias,

lib/Transforms/Scalar/GVN.cpp

@@ -1780,7 +1780,6 @@ 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,

lib/Transforms/Scalar/MemCpyOptimizer.cpp

@@ -743,7 +743,6 @@ 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,

lib/Transforms/Scalar/MergedLoadStoreMotion.cpp

@@ -293,7 +293,7 @@ void MergedLoadStoreMotion::hoistInstruction(BasicBlock *BB,
 
   // Intersect optional metadata.
   HoistCand->intersectOptionalDataWith(ElseInst);
-  HoistCand->dropUnknownMetadata(LLVMContext::MD_dbg);
+  HoistCand->dropUnknownNonDebugMetadata();
 
   // 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(LLVMContext::MD_dbg);
+    S0->dropUnknownNonDebugMetadata();
 
     // Create the new store to be inserted at the join point.
     StoreInst *SNew = (StoreInst *)(S0->clone());

lib/Transforms/Utils/Local.cpp

@@ -1290,7 +1290,7 @@ bool llvm::removeUnreachableBlocks(Function &F) {
 
 void llvm::combineMetadata(Instruction *K, const Instruction *J, ArrayRef<unsigned> KnownIDs) {
   SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
-  K->dropUnknownMetadata(KnownIDs);
+  K->dropUnknownNonDebugMetadata(KnownIDs);
   K->getAllMetadataOtherThanDebugLoc(Metadata);
   for (unsigned i = 0, n = Metadata.size(); i < n; ++i) {
     unsigned Kind = Metadata[i].first;

lib/Transforms/Utils/SimplifyCFG.cpp

@@ -1093,7 +1093,6 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
       I2->replaceAllUsesWith(I1);
     I1->intersectOptionalDataWith(I2);
     unsigned KnownIDs[] = {
-      LLVMContext::MD_dbg,
       LLVMContext::MD_tbaa,
       LLVMContext::MD_range,
       LLVMContext::MD_fpmath,
@@ -2200,7 +2199,7 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, unsigned BonusInstThreshold) {
       // only given the branch precondition.
       // For an analogous reason, we must also drop all the metadata whose
       // semantics we don't understand.
-      NewBonusInst->dropUnknownMetadata(LLVMContext::MD_dbg);
+      NewBonusInst->dropUnknownNonDebugMetadata();
 
       PredBlock->getInstList().insert(PBI, NewBonusInst);
       NewBonusInst->takeName(BonusInst);

lib/Transforms/Vectorize/BBVectorize.cpp

@@ -3118,7 +3118,6 @@ namespace {
         K->mutateType(getVecTypeForPair(L->getType(), H->getType()));
 
       unsigned KnownIDs[] = {
-        LLVMContext::MD_dbg,
         LLVMContext::MD_tbaa,
         LLVMContext::MD_alias_scope,
         LLVMContext::MD_noalias,