vendor/llvm/llvm-release_360-r226102

1 files changed, 242 insertions, 50 deletions

diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index 0f20e6df6c965..477fba42412e4 100644
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -40,7 +40,7 @@ Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM, RemapFlags Flags,
 
   // Global values do not need to be seeded into the VM if they
   // are using the identity mapping.
-  if (isa<GlobalValue>(V) || isa<MDString>(V))
+  if (isa<GlobalValue>(V))
     return VM[V] = const_cast<Value*>(V);
   
   if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
@@ -56,57 +56,24 @@ Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM, RemapFlags Flags,
     
     return VM[V] = const_cast<Value*>(V);
   }
-  
 
-  if (const MDNode *MD = dyn_cast<MDNode>(V)) {
+  if (const auto *MDV = dyn_cast<MetadataAsValue>(V)) {
+    const Metadata *MD = MDV->getMetadata();
     // If this is a module-level metadata and we know that nothing at the module
     // level is changing, then use an identity mapping.
-    if (!MD->isFunctionLocal() && (Flags & RF_NoModuleLevelChanges))
-      return VM[V] = const_cast<Value*>(V);
-    
-    // Create a dummy node in case we have a metadata cycle.
-    MDNode *Dummy = MDNode::getTemporary(V->getContext(), None);
-    VM[V] = Dummy;
-    
-    // Check all operands to see if any need to be remapped.
-    for (unsigned i = 0, e = MD->getNumOperands(); i != e; ++i) {
-      Value *OP = MD->getOperand(i);
-      if (!OP) continue;
-      Value *Mapped_OP = MapValue(OP, VM, Flags, TypeMapper, Materializer);
-      // Use identity map if Mapped_Op is null and we can ignore missing
-      // entries.
-      if (Mapped_OP == OP ||
-          (Mapped_OP == nullptr && (Flags & RF_IgnoreMissingEntries)))
-        continue;
-
-      // Ok, at least one operand needs remapping.  
-      SmallVector<Value*, 4> Elts;
-      Elts.reserve(MD->getNumOperands());
-      for (i = 0; i != e; ++i) {
-        Value *Op = MD->getOperand(i);
-        if (!Op)
-          Elts.push_back(nullptr);
-        else {
-          Value *Mapped_Op = MapValue(Op, VM, Flags, TypeMapper, Materializer);
-          // Use identity map if Mapped_Op is null and we can ignore missing
-          // entries.
-          if (Mapped_Op == nullptr && (Flags & RF_IgnoreMissingEntries))
-            Mapped_Op = Op;
-          Elts.push_back(Mapped_Op);
-        }
-      }
-      MDNode *NewMD = MDNode::get(V->getContext(), Elts);
-      Dummy->replaceAllUsesWith(NewMD);
-      VM[V] = NewMD;
-      MDNode::deleteTemporary(Dummy);
-      return NewMD;
-    }
+    if (!isa<LocalAsMetadata>(MD) && (Flags & RF_NoModuleLevelChanges))
+      return VM[V] = const_cast<Value *>(V);
 
-    VM[V] = const_cast<Value*>(V);
-    MDNode::deleteTemporary(Dummy);
+    auto *MappedMD = MapMetadata(MD, VM, Flags, TypeMapper, Materializer);
+    if (MD == MappedMD || (!MappedMD && (Flags & RF_IgnoreMissingEntries)))
+      return VM[V] = const_cast<Value *>(V);
 
-    // No operands needed remapping.  Use an identity mapping.
-    return const_cast<Value*>(V);
+    // FIXME: This assert crashes during bootstrap, but I think it should be
+    // correct.  For now, just match behaviour from before the metadata/value
+    // split.
+    //
+    //    assert(MappedMD && "Referenced metadata value not in value map");
+    return VM[V] = MetadataAsValue::get(V->getContext(), MappedMD);
   }
 
   // Okay, this either must be a constant (which may or may not be mappable) or
@@ -177,6 +144,229 @@ Value *llvm::MapValue(const Value *V, ValueToValueMapTy &VM, RemapFlags Flags,
   return VM[V] = ConstantPointerNull::get(cast<PointerType>(NewTy));
 }
 
+static Metadata *mapToMetadata(ValueToValueMapTy &VM, const Metadata *Key,
+                     Metadata *Val) {
+  VM.MD()[Key].reset(Val);
+  return Val;
+}
+
+static Metadata *mapToSelf(ValueToValueMapTy &VM, const Metadata *MD) {
+  return mapToMetadata(VM, MD, const_cast<Metadata *>(MD));
+}
+
+static Metadata *MapMetadataImpl(const Metadata *MD, ValueToValueMapTy &VM,
+                                 RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer);
+
+static Metadata *mapMetadataOp(Metadata *Op, ValueToValueMapTy &VM,
+                                 RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer) {
+  if (!Op)
+    return nullptr;
+  if (Metadata *MappedOp =
+          MapMetadataImpl(Op, VM, Flags, TypeMapper, Materializer))
+    return MappedOp;
+  // Use identity map if MappedOp is null and we can ignore missing entries.
+  if (Flags & RF_IgnoreMissingEntries)
+    return Op;
+
+  // FIXME: This assert crashes during bootstrap, but I think it should be
+  // correct.  For now, just match behaviour from before the metadata/value
+  // split.
+  //
+  //    llvm_unreachable("Referenced metadata not in value map!");
+  return nullptr;
+}
+
+static Metadata *cloneMDTuple(const MDTuple *Node, ValueToValueMapTy &VM,
+                              RemapFlags Flags,
+                              ValueMapTypeRemapper *TypeMapper,
+                              ValueMaterializer *Materializer,
+                              bool IsDistinct) {
+  // Distinct MDTuples have their own code path.
+  assert(!IsDistinct && "Unexpected distinct tuple");
+  (void)IsDistinct;
+
+  SmallVector<Metadata *, 4> Elts;
+  Elts.reserve(Node->getNumOperands());
+  for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I)
+    Elts.push_back(mapMetadataOp(Node->getOperand(I), VM, Flags, TypeMapper,
+                                 Materializer));
+
+  return MDTuple::get(Node->getContext(), Elts);
+}
+
+static Metadata *cloneMDLocation(const MDLocation *Node, ValueToValueMapTy &VM,
+                                 RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer,
+                                 bool IsDistinct) {
+  return (IsDistinct ? MDLocation::getDistinct : MDLocation::get)(
+      Node->getContext(), Node->getLine(), Node->getColumn(),
+      mapMetadataOp(Node->getScope(), VM, Flags, TypeMapper, Materializer),
+      mapMetadataOp(Node->getInlinedAt(), VM, Flags, TypeMapper, Materializer));
+}
+
+static Metadata *cloneMDNode(const UniquableMDNode *Node, ValueToValueMapTy &VM,
+                             RemapFlags Flags, ValueMapTypeRemapper *TypeMapper,
+                             ValueMaterializer *Materializer, bool IsDistinct) {
+  switch (Node->getMetadataID()) {
+  default:
+    llvm_unreachable("Invalid UniquableMDNode subclass");
+#define HANDLE_UNIQUABLE_LEAF(CLASS)                                           \
+  case Metadata::CLASS##Kind:                                                  \
+    return clone##CLASS(cast<CLASS>(Node), VM, Flags, TypeMapper,              \
+                        Materializer, IsDistinct);
+#include "llvm/IR/Metadata.def"
+  }
+}
+
+/// \brief Map a distinct MDNode.
+///
+/// Distinct nodes are not uniqued, so they must always recreated.
+static Metadata *mapDistinctNode(const UniquableMDNode *Node,
+                                 ValueToValueMapTy &VM, RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer) {
+  assert(Node->isDistinct() && "Expected distinct node");
+
+  // Optimization for MDTuples.
+  if (isa<MDTuple>(Node)) {
+    // Create the node first so it's available for cyclical references.
+    SmallVector<Metadata *, 4> EmptyOps(Node->getNumOperands());
+    MDTuple *NewMD = MDTuple::getDistinct(Node->getContext(), EmptyOps);
+    mapToMetadata(VM, Node, NewMD);
+
+    // Fix the operands.
+    for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I)
+      NewMD->replaceOperandWith(I, mapMetadataOp(Node->getOperand(I), VM, Flags,
+                                                 TypeMapper, Materializer));
+
+    return NewMD;
+  }
+
+  // In general we need a dummy node, since whether the operands are null can
+  // affect the size of the node.
+  std::unique_ptr<MDNodeFwdDecl> Dummy(
+      MDNode::getTemporary(Node->getContext(), None));
+  mapToMetadata(VM, Node, Dummy.get());
+  Metadata *NewMD = cloneMDNode(Node, VM, Flags, TypeMapper, Materializer,
+                                /* IsDistinct */ true);
+  Dummy->replaceAllUsesWith(NewMD);
+  return mapToMetadata(VM, Node, NewMD);
+}
+
+/// \brief Check whether a uniqued node needs to be remapped.
+///
+/// Check whether a uniqued node needs to be remapped (due to any operands
+/// changing).
+static bool shouldRemapUniquedNode(const UniquableMDNode *Node,
+                                   ValueToValueMapTy &VM, RemapFlags Flags,
+                                   ValueMapTypeRemapper *TypeMapper,
+                                   ValueMaterializer *Materializer) {
+  // Check all operands to see if any need to be remapped.
+  for (unsigned I = 0, E = Node->getNumOperands(); I != E; ++I) {
+    Metadata *Op = Node->getOperand(I);
+    if (Op != mapMetadataOp(Op, VM, Flags, TypeMapper, Materializer))
+      return true;
+  }
+  return false;
+}
+
+/// \brief Map a uniqued MDNode.
+///
+/// Uniqued nodes may not need to be recreated (they may map to themselves).
+static Metadata *mapUniquedNode(const UniquableMDNode *Node,
+                                 ValueToValueMapTy &VM, RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer) {
+  assert(!Node->isDistinct() && "Expected uniqued node");
+
+  // Create a dummy node in case we have a metadata cycle.
+  MDNodeFwdDecl *Dummy = MDNode::getTemporary(Node->getContext(), None);
+  mapToMetadata(VM, Node, Dummy);
+
+  // Check all operands to see if any need to be remapped.
+  if (!shouldRemapUniquedNode(Node, VM, Flags, TypeMapper, Materializer)) {
+    // Use an identity mapping.
+    mapToSelf(VM, Node);
+    MDNode::deleteTemporary(Dummy);
+    return const_cast<Metadata *>(static_cast<const Metadata *>(Node));
+  }
+
+  // At least one operand needs remapping.
+  Metadata *NewMD = cloneMDNode(Node, VM, Flags, TypeMapper, Materializer,
+                                /* IsDistinct */ false);
+  Dummy->replaceAllUsesWith(NewMD);
+  MDNode::deleteTemporary(Dummy);
+  return mapToMetadata(VM, Node, NewMD);
+}
+
+static Metadata *MapMetadataImpl(const Metadata *MD, ValueToValueMapTy &VM,
+                                 RemapFlags Flags,
+                                 ValueMapTypeRemapper *TypeMapper,
+                                 ValueMaterializer *Materializer) {
+  // If the value already exists in the map, use it.
+  if (Metadata *NewMD = VM.MD().lookup(MD).get())
+    return NewMD;
+
+  if (isa<MDString>(MD))
+    return mapToSelf(VM, MD);
+
+  if (isa<ConstantAsMetadata>(MD))
+    if ((Flags & RF_NoModuleLevelChanges))
+      return mapToSelf(VM, MD);
+
+  if (const auto *VMD = dyn_cast<ValueAsMetadata>(MD)) {
+    Value *MappedV =
+        MapValue(VMD->getValue(), VM, Flags, TypeMapper, Materializer);
+    if (VMD->getValue() == MappedV ||
+        (!MappedV && (Flags & RF_IgnoreMissingEntries)))
+      return mapToSelf(VM, MD);
+
+    // FIXME: This assert crashes during bootstrap, but I think it should be
+    // correct.  For now, just match behaviour from before the metadata/value
+    // split.
+    //
+    //    assert(MappedV && "Referenced metadata not in value map!");
+    if (MappedV)
+      return mapToMetadata(VM, MD, ValueAsMetadata::get(MappedV));
+    return nullptr;
+  }
+
+  const UniquableMDNode *Node = cast<UniquableMDNode>(MD);
+  assert(Node->isResolved() && "Unexpected unresolved node");
+
+  // If this is a module-level metadata and we know that nothing at the
+  // module level is changing, then use an identity mapping.
+  if (Flags & RF_NoModuleLevelChanges)
+    return mapToSelf(VM, MD);
+
+  if (Node->isDistinct())
+    return mapDistinctNode(Node, VM, Flags, TypeMapper, Materializer);
+
+  return mapUniquedNode(Node, VM, Flags, TypeMapper, Materializer);
+}
+
+Metadata *llvm::MapMetadata(const Metadata *MD, ValueToValueMapTy &VM,
+                            RemapFlags Flags, ValueMapTypeRemapper *TypeMapper,
+                            ValueMaterializer *Materializer) {
+  Metadata *NewMD = MapMetadataImpl(MD, VM, Flags, TypeMapper, Materializer);
+  if (NewMD && NewMD != MD)
+    if (auto *N = dyn_cast<UniquableMDNode>(NewMD))
+      N->resolveCycles();
+  return NewMD;
+}
+
+MDNode *llvm::MapMetadata(const MDNode *MD, ValueToValueMapTy &VM,
+                          RemapFlags Flags, ValueMapTypeRemapper *TypeMapper,
+                          ValueMaterializer *Materializer) {
+  return cast<MDNode>(MapMetadata(static_cast<const Metadata *>(MD), VM, Flags,
+                                  TypeMapper, Materializer));
+}
+
 /// RemapInstruction - Convert the instruction operands from referencing the
 /// current values into those specified by VMap.
 ///
@@ -210,10 +400,12 @@ void llvm::RemapInstruction(Instruction *I, ValueToValueMapTy &VMap,
   // Remap attached metadata.
   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
   I->getAllMetadata(MDs);
-  for (SmallVectorImpl<std::pair<unsigned, MDNode *> >::iterator
-       MI = MDs.begin(), ME = MDs.end(); MI != ME; ++MI) {
+  for (SmallVectorImpl<std::pair<unsigned, MDNode *>>::iterator
+           MI = MDs.begin(),
+           ME = MDs.end();
+       MI != ME; ++MI) {
     MDNode *Old = MI->second;
-    MDNode *New = MapValue(Old, VMap, Flags, TypeMapper, Materializer);
+    MDNode *New = MapMetadata(Old, VMap, Flags, TypeMapper, Materializer);
     if (New != Old)
       I->setMetadata(MI->first, New);
   }