[Loop Utils] Move utilty addStringMetadataToLoop to LoopUtils.cpp. NFC.

[skatkov]

Summary

Just move the utility function to LoopUtils.cpp to re-use it in loop peeling.

[reames]

LGTM. This really didn't need review. Feel free to move code around in NFC commits without pre-review.

llvm/lib/Transforms/Scalar/LoopVersioningLICM.cpp

 
 /// Threshold for maximum allowed loop nest/depth
 static cl::opt<unsigned> LVLoopDepthThreshold(
     "licm-versioning-max-depth-threshold",
     cl::desc(
         "LoopVersioningLICM's threshold for maximum allowed loop nest/depth"),
     cl::init(2), cl::Hidden);
 
-/// Create MDNode for input string.
-static MDNode *createStringMetadata(Loop *TheLoop, StringRef Name, unsigned V) {
-  LLVMContext &Context = TheLoop->getHeader()->getContext();
-  Metadata *MDs[] = {
-      MDString::get(Context, Name),
-      ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), V))};
-  return MDNode::get(Context, MDs);
-}
-
-/// Set input string into loop metadata by keeping other values intact.
-void llvm::addStringMetadataToLoop(Loop *TheLoop, const char *MDString,
-                                   unsigned V) {
-  SmallVector<Metadata *, 4> MDs(1);
-  // If the loop already has metadata, retain it.
-  MDNode *LoopID = TheLoop->getLoopID();
-  if (LoopID) {
-    for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
-      MDNode *Node = cast<MDNode>(LoopID->getOperand(i));
-      MDs.push_back(Node);
-    }
-  }
-  // Add new metadata.
-  MDs.push_back(createStringMetadata(TheLoop, MDString, V));
-  // Replace current metadata node with new one.
-  LLVMContext &Context = TheLoop->getHeader()->getContext();
-  MDNode *NewLoopID = MDNode::get(Context, MDs);
-  // Set operand 0 to refer to the loop id itself.
-  NewLoopID->replaceOperandWith(0, NewLoopID);
-  TheLoop->setLoopID(NewLoopID);
-}
-
 namespace {
 
 struct LoopVersioningLICM : public LoopPass {
   static char ID;
 
   LoopVersioningLICM()
       : LoopPass(ID), LoopDepthThreshold(LVLoopDepthThreshold),
         InvariantThreshold(LVInvarThreshold) {

llvm/lib/Transforms/Utils/LoopUtils.cpp

void llvm::initializeLoopPassPass(PassRegistry &Registry) {
   INITIALIZE_PASS_DEPENDENCY(LCSSAWrapperPass)
   INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
   INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass)
   INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
   INITIALIZE_PASS_DEPENDENCY(SCEVAAWrapperPass)
   INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
 }
 
+/// Create MDNode for input string.
+static MDNode *createStringMetadata(Loop *TheLoop, StringRef Name, unsigned V) {
+  LLVMContext &Context = TheLoop->getHeader()->getContext();
+  Metadata *MDs[] = {
+      MDString::get(Context, Name),
+      ConstantAsMetadata::get(ConstantInt::get(Type::getInt32Ty(Context), V))};
+  return MDNode::get(Context, MDs);
+}
+
+/// Set input string into loop metadata by keeping other values intact.
+void llvm::addStringMetadataToLoop(Loop *TheLoop, const char *MDString,
+                                   unsigned V) {
+  SmallVector<Metadata *, 4> MDs(1);
+  // If the loop already has metadata, retain it.
+  MDNode *LoopID = TheLoop->getLoopID();
+  if (LoopID) {
+    for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
+      MDNode *Node = cast<MDNode>(LoopID->getOperand(i));
+      MDs.push_back(Node);
+    }
+  }
+  // Add new metadata.
+  MDs.push_back(createStringMetadata(TheLoop, MDString, V));
+  // Replace current metadata node with new one.
+  LLVMContext &Context = TheLoop->getHeader()->getContext();
+  MDNode *NewLoopID = MDNode::get(Context, MDs);
+  // Set operand 0 to refer to the loop id itself.
+  NewLoopID->replaceOperandWith(0, NewLoopID);
+  TheLoop->setLoopID(NewLoopID);
+}
+
 /// Find string metadata for loop
 ///
 /// If it has a value (e.g. {"llvm.distribute", 1} return the value as an
 /// operand or null otherwise.  If the string metadata is not found return
 /// Optional's not-a-value.
 Optional<const MDOperand *> llvm::findStringMetadataForLoop(const Loop *TheLoop,
                                                             StringRef Name) {
   MDNode *MD = findOptionMDForLoop(TheLoop, Name);