X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FIR%2FAttributes.cpp;h=d909f7b880c08239c72795c3b219465ba4a10e1b;hp=59e86f02a0e42422bdadf468255881785c2f85e9;hb=996ace13c0eca0ce1c21df9d7b84966416dd1c21;hpb=c6077eff8b9963b59de21e5d1dfae7a6ea75da36

diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index 59e86f02a0e..d909f7b880c 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -16,6 +16,7 @@
 #include "llvm/IR/Attributes.h"
 #include "AttributeImpl.h"
 #include "LLVMContextImpl.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/Type.h"
 #include "llvm/Support/Atomic.h"
@@ -30,15 +31,12 @@ using namespace llvm;
 // Attribute Construction Methods
 //===----------------------------------------------------------------------===//
 
-Attribute Attribute::get(LLVMContext &Context, AttrKind Kind,
-                         Constant *Val) {
-  if (Kind == None) return Attribute();
-
-  // Otherwise, build a key to look up the existing attributes.
+Attribute Attribute::get(LLVMContext &Context, Attribute::AttrKind Kind,
+                         uint64_t Val) {
   LLVMContextImpl *pImpl = Context.pImpl;
   FoldingSetNodeID ID;
   ID.AddInteger(Kind);
-  ID.AddPointer(Val);
+  if (Val) ID.AddInteger(Val);
 
   void *InsertPoint;
   AttributeImpl *PA = pImpl->AttrsSet.FindNodeOrInsertPos(ID, InsertPoint);
@@ -46,144 +44,286 @@ Attribute Attribute::get(LLVMContext &Context, AttrKind Kind,
   if (!PA) {
     // If we didn't find any existing attributes of the same shape then create a
     // new one and insert it.
-    PA = (!Val) ?
-      new AttributeImpl(Context, Kind) :
-      new AttributeImpl(Context, Kind, Val);
+    if (!Val)
+      PA = new EnumAttributeImpl(Kind);
+    else
+      PA = new IntAttributeImpl(Kind, Val);
     pImpl->AttrsSet.InsertNode(PA, InsertPoint);
   }
 
-  // Return the AttributesList that we found or created.
+  // Return the Attribute that we found or created.
+  return Attribute(PA);
+}
+
+Attribute Attribute::get(LLVMContext &Context, StringRef Kind, StringRef Val) {
+  LLVMContextImpl *pImpl = Context.pImpl;
+  FoldingSetNodeID ID;
+  ID.AddString(Kind);
+  if (!Val.empty()) ID.AddString(Val);
+
+  void *InsertPoint;
+  AttributeImpl *PA = pImpl->AttrsSet.FindNodeOrInsertPos(ID, InsertPoint);
+
+  if (!PA) {
+    // If we didn't find any existing attributes of the same shape then create a
+    // new one and insert it.
+    PA = new StringAttributeImpl(Kind, Val);
+    pImpl->AttrsSet.InsertNode(PA, InsertPoint);
+  }
+
+  // Return the Attribute that we found or created.
   return Attribute(PA);
 }
 
 Attribute Attribute::getWithAlignment(LLVMContext &Context, uint64_t Align) {
-  return get(Context, Attribute::Alignment,
-             ConstantInt::get(Type::getInt64Ty(Context), Align));
+  assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
+  assert(Align <= 0x40000000 && "Alignment too large.");
+  return get(Context, Alignment, Align);
 }
 
 Attribute Attribute::getWithStackAlignment(LLVMContext &Context,
                                            uint64_t Align) {
-  return get(Context, Attribute::StackAlignment,
-             ConstantInt::get(Type::getInt64Ty(Context), Align));
+  assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
+  assert(Align <= 0x100 && "Alignment too large.");
+  return get(Context, StackAlignment, Align);
+}
+
+Attribute Attribute::getWithDereferenceableBytes(LLVMContext &Context,
+                                                uint64_t Bytes) {
+  assert(Bytes && "Bytes must be non-zero.");
+  return get(Context, Dereferenceable, Bytes);
+}
+
+Attribute Attribute::getWithDereferenceableOrNullBytes(LLVMContext &Context,
+                                                       uint64_t Bytes) {
+  assert(Bytes && "Bytes must be non-zero.");
+  return get(Context, DereferenceableOrNull, Bytes);
 }
 
 //===----------------------------------------------------------------------===//
 // Attribute Accessor Methods
 //===----------------------------------------------------------------------===//
 
-bool Attribute::hasAttribute(AttrKind Val) const {
-  return pImpl && pImpl->hasAttribute(Val);
+bool Attribute::isEnumAttribute() const {
+  return pImpl && pImpl->isEnumAttribute();
 }
 
-bool Attribute::hasAttributes() const {
-  return pImpl && pImpl->hasAttributes();
+bool Attribute::isIntAttribute() const {
+  return pImpl && pImpl->isIntAttribute();
 }
 
-Constant *Attribute::getAttributeKind() const {
-  return pImpl ? pImpl->getAttributeKind() : 0;
+bool Attribute::isStringAttribute() const {
+  return pImpl && pImpl->isStringAttribute();
+}
+
+Attribute::AttrKind Attribute::getKindAsEnum() const {
+  if (!pImpl) return None;
+  assert((isEnumAttribute() || isIntAttribute()) &&
+         "Invalid attribute type to get the kind as an enum!");
+  return pImpl ? pImpl->getKindAsEnum() : None;
+}
+
+uint64_t Attribute::getValueAsInt() const {
+  if (!pImpl) return 0;
+  assert(isIntAttribute() &&
+         "Expected the attribute to be an integer attribute!");
+  return pImpl ? pImpl->getValueAsInt() : 0;
 }
 
-ArrayRef<Constant*> Attribute::getAttributeValues() const {
-  return pImpl ? pImpl->getAttributeValues() : ArrayRef<Constant*>();
+StringRef Attribute::getKindAsString() const {
+  if (!pImpl) return StringRef();
+  assert(isStringAttribute() &&
+         "Invalid attribute type to get the kind as a string!");
+  return pImpl ? pImpl->getKindAsString() : StringRef();
+}
+
+StringRef Attribute::getValueAsString() const {
+  if (!pImpl) return StringRef();
+  assert(isStringAttribute() &&
+         "Invalid attribute type to get the value as a string!");
+  return pImpl ? pImpl->getValueAsString() : StringRef();
+}
+
+bool Attribute::hasAttribute(AttrKind Kind) const {
+  return (pImpl && pImpl->hasAttribute(Kind)) || (!pImpl && Kind == None);
+}
+
+bool Attribute::hasAttribute(StringRef Kind) const {
+  if (!isStringAttribute()) return false;
+  return pImpl && pImpl->hasAttribute(Kind);
 }
 
 /// This returns the alignment field of an attribute as a byte alignment value.
 unsigned Attribute::getAlignment() const {
-  if (!hasAttribute(Attribute::Alignment))
-    return 0;
-  return pImpl->getAlignment();
+  assert(hasAttribute(Attribute::Alignment) &&
+         "Trying to get alignment from non-alignment attribute!");
+  return pImpl->getValueAsInt();
 }
 
 /// This returns the stack alignment field of an attribute as a byte alignment
 /// value.
 unsigned Attribute::getStackAlignment() const {
-  if (!hasAttribute(Attribute::StackAlignment))
-    return 0;
-  return pImpl->getStackAlignment();
+  assert(hasAttribute(Attribute::StackAlignment) &&
+         "Trying to get alignment from non-alignment attribute!");
+  return pImpl->getValueAsInt();
 }
 
-std::string Attribute::getAsString() const {
-  if (hasAttribute(Attribute::ZExt))
-    return "zeroext";
-  if (hasAttribute(Attribute::SExt))
-    return "signext";
-  if (hasAttribute(Attribute::NoReturn))
-    return "noreturn";
-  if (hasAttribute(Attribute::NoUnwind))
-    return "nounwind";
-  if (hasAttribute(Attribute::UWTable))
-    return "uwtable";
-  if (hasAttribute(Attribute::ReturnsTwice))
-    return "returns_twice";
+/// This returns the number of dereferenceable bytes.
+uint64_t Attribute::getDereferenceableBytes() const {
+  assert(hasAttribute(Attribute::Dereferenceable) &&
+         "Trying to get dereferenceable bytes from "
+         "non-dereferenceable attribute!");
+  return pImpl->getValueAsInt();
+}
+
+uint64_t Attribute::getDereferenceableOrNullBytes() const {
+  assert(hasAttribute(Attribute::DereferenceableOrNull) &&
+         "Trying to get dereferenceable bytes from "
+         "non-dereferenceable attribute!");
+  return pImpl->getValueAsInt();
+}
+
+std::string Attribute::getAsString(bool InAttrGrp) const {
+  if (!pImpl) return "";
+
+  if (hasAttribute(Attribute::SanitizeAddress))
+    return "sanitize_address";
+  if (hasAttribute(Attribute::AlwaysInline))
+    return "alwaysinline";
+  if (hasAttribute(Attribute::ArgMemOnly))
+    return "argmemonly";
+  if (hasAttribute(Attribute::Builtin))
+    return "builtin";
+  if (hasAttribute(Attribute::ByVal))
+    return "byval";
+  if (hasAttribute(Attribute::Convergent))
+    return "convergent";
+  if (hasAttribute(Attribute::InAlloca))
+    return "inalloca";
+  if (hasAttribute(Attribute::InlineHint))
+    return "inlinehint";
   if (hasAttribute(Attribute::InReg))
     return "inreg";
+  if (hasAttribute(Attribute::JumpTable))
+    return "jumptable";
+  if (hasAttribute(Attribute::MinSize))
+    return "minsize";
+  if (hasAttribute(Attribute::Naked))
+    return "naked";
+  if (hasAttribute(Attribute::Nest))
+    return "nest";
   if (hasAttribute(Attribute::NoAlias))
     return "noalias";
+  if (hasAttribute(Attribute::NoBuiltin))
+    return "nobuiltin";
   if (hasAttribute(Attribute::NoCapture))
     return "nocapture";
-  if (hasAttribute(Attribute::StructRet))
-    return "sret";
-  if (hasAttribute(Attribute::ByVal))
-    return "byval";
-  if (hasAttribute(Attribute::Nest))
-    return "nest";
+  if (hasAttribute(Attribute::NoDuplicate))
+    return "noduplicate";
+  if (hasAttribute(Attribute::NoImplicitFloat))
+    return "noimplicitfloat";
+  if (hasAttribute(Attribute::NoInline))
+    return "noinline";
+  if (hasAttribute(Attribute::NonLazyBind))
+    return "nonlazybind";
+  if (hasAttribute(Attribute::NonNull))
+    return "nonnull";
+  if (hasAttribute(Attribute::NoRedZone))
+    return "noredzone";
+  if (hasAttribute(Attribute::NoReturn))
+    return "noreturn";
+  if (hasAttribute(Attribute::NoUnwind))
+    return "nounwind";
+  if (hasAttribute(Attribute::OptimizeNone))
+    return "optnone";
+  if (hasAttribute(Attribute::OptimizeForSize))
+    return "optsize";
   if (hasAttribute(Attribute::ReadNone))
     return "readnone";
   if (hasAttribute(Attribute::ReadOnly))
     return "readonly";
-  if (hasAttribute(Attribute::OptimizeForSize))
-    return "optsize";
-  if (hasAttribute(Attribute::NoInline))
-    return "noinline";
-  if (hasAttribute(Attribute::InlineHint))
-    return "inlinehint";
-  if (hasAttribute(Attribute::AlwaysInline))
-    return "alwaysinline";
+  if (hasAttribute(Attribute::Returned))
+    return "returned";
+  if (hasAttribute(Attribute::ReturnsTwice))
+    return "returns_twice";
+  if (hasAttribute(Attribute::SExt))
+    return "signext";
   if (hasAttribute(Attribute::StackProtect))
     return "ssp";
   if (hasAttribute(Attribute::StackProtectReq))
     return "sspreq";
   if (hasAttribute(Attribute::StackProtectStrong))
     return "sspstrong";
-  if (hasAttribute(Attribute::NoRedZone))
-    return "noredzone";
-  if (hasAttribute(Attribute::NoImplicitFloat))
-    return "noimplicitfloat";
-  if (hasAttribute(Attribute::Naked))
-    return "naked";
-  if (hasAttribute(Attribute::NonLazyBind))
-    return "nonlazybind";
-  if (hasAttribute(Attribute::AddressSafety))
-    return "address_safety";
-  if (hasAttribute(Attribute::MinSize))
-    return "minsize";
-  if (hasAttribute(Attribute::StackAlignment)) {
+  if (hasAttribute(Attribute::SafeStack))
+    return "safestack";
+  if (hasAttribute(Attribute::StructRet))
+    return "sret";
+  if (hasAttribute(Attribute::SanitizeThread))
+    return "sanitize_thread";
+  if (hasAttribute(Attribute::SanitizeMemory))
+    return "sanitize_memory";
+  if (hasAttribute(Attribute::UWTable))
+    return "uwtable";
+  if (hasAttribute(Attribute::ZExt))
+    return "zeroext";
+  if (hasAttribute(Attribute::Cold))
+    return "cold";
+
+  // FIXME: These should be output like this:
+  //
+  //   align=4
+  //   alignstack=8
+  //
+  if (hasAttribute(Attribute::Alignment)) {
     std::string Result;
-    Result += "alignstack(";
-    Result += utostr(getStackAlignment());
-    Result += ")";
+    Result += "align";
+    Result += (InAttrGrp) ? "=" : " ";
+    Result += utostr(getValueAsInt());
     return Result;
   }
-  if (hasAttribute(Attribute::Alignment)) {
+
+  auto AttrWithBytesToString = [&](const char *Name) {
+    std::string Result;
+    Result += Name;
+    if (InAttrGrp) {
+      Result += "=";
+      Result += utostr(getValueAsInt());
+    } else {
+      Result += "(";
+      Result += utostr(getValueAsInt());
+      Result += ")";
+    }
+    return Result;
+  };
+
+  if (hasAttribute(Attribute::StackAlignment))
+    return AttrWithBytesToString("alignstack");
+
+  if (hasAttribute(Attribute::Dereferenceable))
+    return AttrWithBytesToString("dereferenceable");
+
+  if (hasAttribute(Attribute::DereferenceableOrNull))
+    return AttrWithBytesToString("dereferenceable_or_null");
+
+  // Convert target-dependent attributes to strings of the form:
+  //
+  //   "kind"
+  //   "kind" = "value"
+  //
+  if (isStringAttribute()) {
     std::string Result;
-    Result += "align ";
-    Result += utostr(getAlignment());
-    Result += "";
+    Result += (Twine('"') + getKindAsString() + Twine('"')).str();
+
+    StringRef Val = pImpl->getValueAsString();
+    if (Val.empty()) return Result;
+
+    Result += ("=\"" + Val + Twine('"')).str();
     return Result;
   }
-  if (hasAttribute(Attribute::NoDuplicate))
-    return "noduplicate";
 
   llvm_unreachable("Unknown attribute");
 }
 
-bool Attribute::operator==(AttrKind K) const {
-  return pImpl && *pImpl == K;
-}
-bool Attribute::operator!=(AttrKind K) const {
-  return !(*this == K);
-}
-
 bool Attribute::operator<(Attribute A) const {
   if (!pImpl && !A.pImpl) return false;
   if (!pImpl) return true;
@@ -191,102 +331,72 @@ bool Attribute::operator<(Attribute A) const {
   return *pImpl < *A.pImpl;
 }
 
-uint64_t Attribute::Raw() const {
-  return pImpl ? pImpl->Raw() : 0;
-}
-
 //===----------------------------------------------------------------------===//
 // AttributeImpl Definition
 //===----------------------------------------------------------------------===//
 
-AttributeImpl::AttributeImpl(LLVMContext &C, Attribute::AttrKind kind)
-  : Context(C) {
-  Kind = ConstantInt::get(Type::getInt64Ty(C), kind);
-}
-AttributeImpl::AttributeImpl(LLVMContext &C, Attribute::AttrKind kind,
-                             ArrayRef<Constant*> values)
-  : Context(C) {
-  Kind = ConstantInt::get(Type::getInt64Ty(C), kind);
-  Vals.reserve(values.size());
-  Vals.append(values.begin(), values.end());
-}
-AttributeImpl::AttributeImpl(LLVMContext &C, StringRef kind)
-  : Context(C) {
-  Kind = ConstantDataArray::getString(C, kind);
-}
+// Pin the vtables to this file.
+AttributeImpl::~AttributeImpl() {}
+void EnumAttributeImpl::anchor() {}
+void IntAttributeImpl::anchor() {}
+void StringAttributeImpl::anchor() {}
 
 bool AttributeImpl::hasAttribute(Attribute::AttrKind A) const {
-  return (Raw() & getAttrMask(A)) != 0;
-}
-
-bool AttributeImpl::hasAttributes() const {
-  return Raw() != 0;
+  if (isStringAttribute()) return false;
+  return getKindAsEnum() == A;
 }
 
-uint64_t AttributeImpl::getAlignment() const {
-  uint64_t Mask = Raw() & getAttrMask(Attribute::Alignment);
-  return 1ULL << ((Mask >> 16) - 1);
+bool AttributeImpl::hasAttribute(StringRef Kind) const {
+  if (!isStringAttribute()) return false;
+  return getKindAsString() == Kind;
 }
 
-uint64_t AttributeImpl::getStackAlignment() const {
-  uint64_t Mask = Raw() & getAttrMask(Attribute::StackAlignment);
-  return 1ULL << ((Mask >> 26) - 1);
+Attribute::AttrKind AttributeImpl::getKindAsEnum() const {
+  assert(isEnumAttribute() || isIntAttribute());
+  return static_cast<const EnumAttributeImpl *>(this)->getEnumKind();
 }
 
-bool AttributeImpl::operator==(Attribute::AttrKind kind) const {
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(Kind))
-    return CI->getZExtValue() == kind;
-  return false;
-}
-bool AttributeImpl::operator!=(Attribute::AttrKind kind) const {
-  return !(*this == kind);
+uint64_t AttributeImpl::getValueAsInt() const {
+  assert(isIntAttribute());
+  return static_cast<const IntAttributeImpl *>(this)->getValue();
 }
 
-bool AttributeImpl::operator==(StringRef kind) const {
-  if (ConstantDataArray *CDA = dyn_cast<ConstantDataArray>(Kind))
-    if (CDA->isString())
-      return CDA->getAsString() == kind;
-  return false;
+StringRef AttributeImpl::getKindAsString() const {
+  assert(isStringAttribute());
+  return static_cast<const StringAttributeImpl *>(this)->getStringKind();
 }
 
-bool AttributeImpl::operator!=(StringRef kind) const {
-  return !(*this == kind);
+StringRef AttributeImpl::getValueAsString() const {
+  assert(isStringAttribute());
+  return static_cast<const StringAttributeImpl *>(this)->getStringValue();
 }
 
 bool AttributeImpl::operator<(const AttributeImpl &AI) const {
-  if (!Kind && !AI.Kind) return false;
-  if (!Kind && AI.Kind) return true;
-  if (Kind && !AI.Kind) return false;
-
-  ConstantInt *ThisCI = dyn_cast<ConstantInt>(Kind);
-  ConstantInt *ThatCI = dyn_cast<ConstantInt>(AI.Kind);
-
-  ConstantDataArray *ThisCDA = dyn_cast<ConstantDataArray>(Kind);
-  ConstantDataArray *ThatCDA = dyn_cast<ConstantDataArray>(AI.Kind);
-
-  if (ThisCI && ThatCI)
-    return ThisCI->getZExtValue() < ThatCI->getZExtValue();
-
-  if (ThisCI && ThatCDA)
-    return true;
-
-  if (ThisCDA && ThatCI)
-    return false;
+  // This sorts the attributes with Attribute::AttrKinds coming first (sorted
+  // relative to their enum value) and then strings.
+  if (isEnumAttribute()) {
+    if (AI.isEnumAttribute()) return getKindAsEnum() < AI.getKindAsEnum();
+    if (AI.isIntAttribute()) return true;
+    if (AI.isStringAttribute()) return true;
+  }
 
-  return ThisCDA->getAsString() < ThatCDA->getAsString();
-}
+  if (isIntAttribute()) {
+    if (AI.isEnumAttribute()) return false;
+    if (AI.isIntAttribute()) return getValueAsInt() < AI.getValueAsInt();
+    if (AI.isStringAttribute()) return true;
+  }
 
-uint64_t AttributeImpl::Raw() const {
-  // FIXME: Remove this.
-  return cast<ConstantInt>(Kind)->getZExtValue();
+  if (AI.isEnumAttribute()) return false;
+  if (AI.isIntAttribute()) return false;
+  if (getKindAsString() == AI.getKindAsString())
+    return getValueAsString() < AI.getValueAsString();
+  return getKindAsString() < AI.getKindAsString();
 }
 
 uint64_t AttributeImpl::getAttrMask(Attribute::AttrKind Val) {
   // FIXME: Remove this.
   switch (Val) {
   case Attribute::EndAttrKinds:
-  case Attribute::AttrKindEmptyKey:
-  case Attribute::AttrKindTombstoneKey:
     llvm_unreachable("Synthetic enumerators which should never get here");
 
   case Attribute::None:            return 0;
@@ -316,10 +426,32 @@ uint64_t AttributeImpl::getAttrMask(Attribute::AttrKind Val) {
   case Attribute::ReturnsTwice:    return 1 << 29;
   case Attribute::UWTable:         return 1 << 30;
   case Attribute::NonLazyBind:     return 1U << 31;
-  case Attribute::AddressSafety:   return 1ULL << 32;
+  case Attribute::SanitizeAddress: return 1ULL << 32;
   case Attribute::MinSize:         return 1ULL << 33;
   case Attribute::NoDuplicate:     return 1ULL << 34;
   case Attribute::StackProtectStrong: return 1ULL << 35;
+  case Attribute::SanitizeThread:  return 1ULL << 36;
+  case Attribute::SanitizeMemory:  return 1ULL << 37;
+  case Attribute::NoBuiltin:       return 1ULL << 38;
+  case Attribute::Returned:        return 1ULL << 39;
+  case Attribute::Cold:            return 1ULL << 40;
+  case Attribute::Builtin:         return 1ULL << 41;
+  case Attribute::OptimizeNone:    return 1ULL << 42;
+  case Attribute::InAlloca:        return 1ULL << 43;
+  case Attribute::NonNull:         return 1ULL << 44;
+  case Attribute::JumpTable:       return 1ULL << 45;
+  case Attribute::Convergent:      return 1ULL << 46;
+  case Attribute::SafeStack:       return 1ULL << 47;
+  case Attribute::Dereferenceable:
+    llvm_unreachable("dereferenceable attribute not supported in raw format");
+    break;
+  case Attribute::DereferenceableOrNull:
+    llvm_unreachable("dereferenceable_or_null attribute not supported in raw "
+                     "format");
+    break;
+  case Attribute::ArgMemOnly:
+    llvm_unreachable("argmemonly attribute not supported in raw format");
+    break;
   }
   llvm_unreachable("Unsupported attribute type");
 }
@@ -331,14 +463,14 @@ uint64_t AttributeImpl::getAttrMask(Attribute::AttrKind Val) {
 AttributeSetNode *AttributeSetNode::get(LLVMContext &C,
                                         ArrayRef<Attribute> Attrs) {
   if (Attrs.empty())
-    return 0;
+    return nullptr;
 
   // Otherwise, build a key to look up the existing attributes.
   LLVMContextImpl *pImpl = C.pImpl;
   FoldingSetNodeID ID;
 
   SmallVector<Attribute, 8> SortedAttrs(Attrs.begin(), Attrs.end());
-  std::sort(SortedAttrs.begin(), SortedAttrs.end());
+  array_pod_sort(SortedAttrs.begin(), SortedAttrs.end());
 
   for (SmallVectorImpl<Attribute>::iterator I = SortedAttrs.begin(),
          E = SortedAttrs.end(); I != E; ++I)
@@ -351,7 +483,9 @@ AttributeSetNode *AttributeSetNode::get(LLVMContext &C,
   // If we didn't find any existing attributes of the same shape then create a
   // new one and insert it.
   if (!PA) {
-    PA = new AttributeSetNode(SortedAttrs);
+    // Coallocate entries after the AttributeSetNode itself.
+    void *Mem = ::operator new(totalSizeToAlloc<Attribute>(SortedAttrs.size()));
+    PA = new (Mem) AttributeSetNode(SortedAttrs);
     pImpl->AttrsSetNodes.InsertNode(PA, InsertPoint);
   }
 
@@ -360,35 +494,67 @@ AttributeSetNode *AttributeSetNode::get(LLVMContext &C,
 }
 
 bool AttributeSetNode::hasAttribute(Attribute::AttrKind Kind) const {
-  for (SmallVectorImpl<Attribute>::const_iterator I = AttrList.begin(),
-         E = AttrList.end(); I != E; ++I)
+  for (iterator I = begin(), E = end(); I != E; ++I)
+    if (I->hasAttribute(Kind))
+      return true;
+  return false;
+}
+
+bool AttributeSetNode::hasAttribute(StringRef Kind) const {
+  for (iterator I = begin(), E = end(); I != E; ++I)
     if (I->hasAttribute(Kind))
       return true;
   return false;
 }
 
+Attribute AttributeSetNode::getAttribute(Attribute::AttrKind Kind) const {
+  for (iterator I = begin(), E = end(); I != E; ++I)
+    if (I->hasAttribute(Kind))
+      return *I;
+  return Attribute();
+}
+
+Attribute AttributeSetNode::getAttribute(StringRef Kind) const {
+  for (iterator I = begin(), E = end(); I != E; ++I)
+    if (I->hasAttribute(Kind))
+      return *I;
+  return Attribute();
+}
+
 unsigned AttributeSetNode::getAlignment() const {
-  for (SmallVectorImpl<Attribute>::const_iterator I = AttrList.begin(),
-         E = AttrList.end(); I != E; ++I)
+  for (iterator I = begin(), E = end(); I != E; ++I)
     if (I->hasAttribute(Attribute::Alignment))
       return I->getAlignment();
   return 0;
 }
 
 unsigned AttributeSetNode::getStackAlignment() const {
-  for (SmallVectorImpl<Attribute>::const_iterator I = AttrList.begin(),
-         E = AttrList.end(); I != E; ++I)
+  for (iterator I = begin(), E = end(); I != E; ++I)
     if (I->hasAttribute(Attribute::StackAlignment))
       return I->getStackAlignment();
   return 0;
 }
 
-std::string AttributeSetNode::getAsString() const {
-  std::string Str = "";
-  for (SmallVectorImpl<Attribute>::const_iterator I = AttrList.begin(),
-         E = AttrList.end(); I != E; ++I) {
-    if (I != AttrList.begin()) Str += " ";
-    Str += I->getAsString();
+uint64_t AttributeSetNode::getDereferenceableBytes() const {
+  for (iterator I = begin(), E = end(); I != E; ++I)
+    if (I->hasAttribute(Attribute::Dereferenceable))
+      return I->getDereferenceableBytes();
+  return 0;
+}
+
+uint64_t AttributeSetNode::getDereferenceableOrNullBytes() const {
+  for (iterator I = begin(), E = end(); I != E; ++I)
+    if (I->hasAttribute(Attribute::DereferenceableOrNull))
+      return I->getDereferenceableOrNullBytes();
+  return 0;
+}
+
+std::string AttributeSetNode::getAsString(bool InAttrGrp) const {
+  std::string Str;
+  for (iterator I = begin(), E = end(); I != E; ++I) {
+    if (I != begin())
+      Str += ' ';
+    Str += I->getAsString(InAttrGrp);
   }
   return Str;
 }
@@ -397,21 +563,41 @@ std::string AttributeSetNode::getAsString() const {
 // AttributeSetImpl Definition
 //===----------------------------------------------------------------------===//
 
-uint64_t AttributeSetImpl::Raw(uint64_t Index) const {
+uint64_t AttributeSetImpl::Raw(unsigned Index) const {
   for (unsigned I = 0, E = getNumAttributes(); I != E; ++I) {
     if (getSlotIndex(I) != Index) continue;
-    const AttributeSetNode *ASN = AttrNodes[I].second;
-    AttrBuilder B;
+    const AttributeSetNode *ASN = getSlotNode(I);
+    uint64_t Mask = 0;
+
+    for (AttributeSetNode::iterator II = ASN->begin(),
+           IE = ASN->end(); II != IE; ++II) {
+      Attribute Attr = *II;
+
+      // This cannot handle string attributes.
+      if (Attr.isStringAttribute()) continue;
+
+      Attribute::AttrKind Kind = Attr.getKindAsEnum();
+
+      if (Kind == Attribute::Alignment)
+        Mask |= (Log2_32(ASN->getAlignment()) + 1) << 16;
+      else if (Kind == Attribute::StackAlignment)
+        Mask |= (Log2_32(ASN->getStackAlignment()) + 1) << 26;
+      else if (Kind == Attribute::Dereferenceable)
+        llvm_unreachable("dereferenceable not supported in bit mask");
+      else
+        Mask |= AttributeImpl::getAttrMask(Kind);
+    }
 
-    for (AttributeSetNode::const_iterator II = ASN->begin(),
-           IE = ASN->end(); II != IE; ++II)
-      B.addAttributes(*II);
-    return B.Raw();
+    return Mask;
   }
 
   return 0;
 }
 
+void AttributeSetImpl::dump() const {
+  AttributeSet(const_cast<AttributeSetImpl *>(this)).dump();
+}
+
 //===----------------------------------------------------------------------===//
 // AttributeSet Construction and Mutation Methods
 //===----------------------------------------------------------------------===//
@@ -429,7 +615,10 @@ AttributeSet::getImpl(LLVMContext &C,
   // If we didn't find any existing attributes of the same shape then
   // create a new one and insert it.
   if (!PA) {
-    PA = new AttributeSetImpl(C, Attrs);
+    // Coallocate entries after the AttributeSetImpl itself.
+    void *Mem = ::operator new(
+        AttributeSetImpl::totalSizeToAlloc<IndexAttrPair>(Attrs.size()));
+    PA = new (Mem) AttributeSetImpl(C, Attrs);
     pImpl->AttrsLists.InsertNode(PA, InsertPoint);
   }
 
@@ -447,7 +636,7 @@ AttributeSet AttributeSet::get(LLVMContext &C,
   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
     assert((!i || Attrs[i-1].first <= Attrs[i].first) &&
            "Misordered Attributes list!");
-    assert(Attrs[i].second.hasAttributes() &&
+    assert(!Attrs[i].second.hasAttribute(Attribute::None) &&
            "Pointless attribute!");
   }
 #endif
@@ -481,54 +670,104 @@ AttributeSet AttributeSet::get(LLVMContext &C,
   return getImpl(C, Attrs);
 }
 
-AttributeSet AttributeSet::get(LLVMContext &C, unsigned Idx, AttrBuilder &B) {
+AttributeSet AttributeSet::get(LLVMContext &C, unsigned Index,
+                               const AttrBuilder &B) {
   if (!B.hasAttributes())
     return AttributeSet();
 
+  // Add target-independent attributes.
   SmallVector<std::pair<unsigned, Attribute>, 8> Attrs;
-  for (AttrBuilder::iterator I = B.begin(), E = B.end(); I != E; ++I) {
-    Attribute::AttrKind Kind = *I;
+  for (Attribute::AttrKind Kind = Attribute::None;
+       Kind != Attribute::EndAttrKinds; Kind = Attribute::AttrKind(Kind + 1)) {
+    if (!B.contains(Kind))
+      continue;
+
     if (Kind == Attribute::Alignment)
-      Attrs.push_back(std::make_pair(Idx, Attribute::
+      Attrs.push_back(std::make_pair(Index, Attribute::
                                      getWithAlignment(C, B.getAlignment())));
     else if (Kind == Attribute::StackAlignment)
-      Attrs.push_back(std::make_pair(Idx, Attribute::
+      Attrs.push_back(std::make_pair(Index, Attribute::
                               getWithStackAlignment(C, B.getStackAlignment())));
+    else if (Kind == Attribute::Dereferenceable)
+      Attrs.push_back(std::make_pair(Index,
+                                     Attribute::getWithDereferenceableBytes(C,
+                                       B.getDereferenceableBytes())));
+    else if (Kind == Attribute::DereferenceableOrNull)
+      Attrs.push_back(
+          std::make_pair(Index, Attribute::getWithDereferenceableOrNullBytes(
+                                    C, B.getDereferenceableOrNullBytes())));
     else
-      Attrs.push_back(std::make_pair(Idx, Attribute::get(C, Kind)));
+      Attrs.push_back(std::make_pair(Index, Attribute::get(C, Kind)));
   }
 
+  // Add target-dependent (string) attributes.
+  for (const AttrBuilder::td_type &TDA : B.td_attrs())
+    Attrs.push_back(
+        std::make_pair(Index, Attribute::get(C, TDA.first, TDA.second)));
+
   return get(C, Attrs);
 }
 
-AttributeSet AttributeSet::get(LLVMContext &C, unsigned Idx,
+AttributeSet AttributeSet::get(LLVMContext &C, unsigned Index,
                                ArrayRef<Attribute::AttrKind> Kind) {
   SmallVector<std::pair<unsigned, Attribute>, 8> Attrs;
   for (ArrayRef<Attribute::AttrKind>::iterator I = Kind.begin(),
          E = Kind.end(); I != E; ++I)
-    Attrs.push_back(std::make_pair(Idx, Attribute::get(C, *I)));
+    Attrs.push_back(std::make_pair(Index, Attribute::get(C, *I)));
   return get(C, Attrs);
 }
 
 AttributeSet AttributeSet::get(LLVMContext &C, ArrayRef<AttributeSet> Attrs) {
   if (Attrs.empty()) return AttributeSet();
+  if (Attrs.size() == 1) return Attrs[0];
 
   SmallVector<std::pair<unsigned, AttributeSetNode*>, 8> AttrNodeVec;
-  for (unsigned I = 0, E = Attrs.size(); I != E; ++I) {
-    AttributeSet AS = Attrs[I];
-    if (!AS.pImpl) continue;
-    AttrNodeVec.append(AS.pImpl->AttrNodes.begin(), AS.pImpl->AttrNodes.end());
+  AttributeSetImpl *A0 = Attrs[0].pImpl;
+  if (A0)
+    AttrNodeVec.append(A0->getNode(0), A0->getNode(A0->getNumAttributes()));
+  // Copy all attributes from Attrs into AttrNodeVec while keeping AttrNodeVec
+  // ordered by index.  Because we know that each list in Attrs is ordered by
+  // index we only need to merge each successive list in rather than doing a
+  // full sort.
+  for (unsigned I = 1, E = Attrs.size(); I != E; ++I) {
+    AttributeSetImpl *AS = Attrs[I].pImpl;
+    if (!AS) continue;
+    SmallVector<std::pair<unsigned, AttributeSetNode *>, 8>::iterator
+      ANVI = AttrNodeVec.begin(), ANVE;
+    for (const IndexAttrPair *AI = AS->getNode(0),
+                             *AE = AS->getNode(AS->getNumAttributes());
+         AI != AE; ++AI) {
+      ANVE = AttrNodeVec.end();
+      while (ANVI != ANVE && ANVI->first <= AI->first)
+        ++ANVI;
+      ANVI = AttrNodeVec.insert(ANVI, *AI) + 1;
+    }
   }
 
   return getImpl(C, AttrNodeVec);
 }
 
-AttributeSet AttributeSet::addAttribute(LLVMContext &C, unsigned Idx,
+AttributeSet AttributeSet::addAttribute(LLVMContext &C, unsigned Index,
                                         Attribute::AttrKind Attr) const {
-  return addAttributes(C, Idx, AttributeSet::get(C, Idx, Attr));
+  if (hasAttribute(Index, Attr)) return *this;
+  return addAttributes(C, Index, AttributeSet::get(C, Index, Attr));
 }
 
-AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
+AttributeSet AttributeSet::addAttribute(LLVMContext &C, unsigned Index,
+                                        StringRef Kind) const {
+  llvm::AttrBuilder B;
+  B.addAttribute(Kind);
+  return addAttributes(C, Index, AttributeSet::get(C, Index, B));
+}
+
+AttributeSet AttributeSet::addAttribute(LLVMContext &C, unsigned Index,
+                                        StringRef Kind, StringRef Value) const {
+  llvm::AttrBuilder B;
+  B.addAttribute(Kind, Value);
+  return addAttributes(C, Index, AttributeSet::get(C, Index, B));
+}
+
+AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Index,
                                          AttributeSet Attrs) const {
   if (!pImpl) return Attrs;
   if (!Attrs.pImpl) return *this;
@@ -536,8 +775,8 @@ AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
 #ifndef NDEBUG
   // FIXME it is not obvious how this should work for alignment. For now, say
   // we can't change a known alignment.
-  unsigned OldAlign = getParamAlignment(Idx);
-  unsigned NewAlign = Attrs.getParamAlignment(Idx);
+  unsigned OldAlign = getParamAlignment(Index);
+  unsigned NewAlign = Attrs.getParamAlignment(Index);
   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
          "Attempt to change alignment!");
 #endif
@@ -548,8 +787,8 @@ AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
   AttributeSet AS;
   uint64_t LastIndex = 0;
   for (unsigned I = 0, E = NumAttrs; I != E; ++I) {
-    if (getSlotIndex(I) >= Idx) {
-      if (getSlotIndex(I) == Idx) AS = getSlotAttributes(LastIndex++);
+    if (getSlotIndex(I) >= Index) {
+      if (getSlotIndex(I) == Index) AS = getSlotAttributes(LastIndex++);
       break;
     }
     LastIndex = I + 1;
@@ -558,17 +797,17 @@ AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
 
   // Now add the attribute into the correct slot. There may already be an
   // AttributeSet there.
-  AttrBuilder B(AS, Idx);
+  AttrBuilder B(AS, Index);
 
   for (unsigned I = 0, E = Attrs.pImpl->getNumAttributes(); I != E; ++I)
-    if (Attrs.getSlotIndex(I) == Idx) {
-      for (AttributeSetImpl::const_iterator II = Attrs.pImpl->begin(I),
+    if (Attrs.getSlotIndex(I) == Index) {
+      for (AttributeSetImpl::iterator II = Attrs.pImpl->begin(I),
              IE = Attrs.pImpl->end(I); II != IE; ++II)
-        B.addAttributes(*II);
+        B.addAttribute(*II);
       break;
     }
 
-  AttrSet.push_back(AttributeSet::get(C, Idx, B));
+  AttrSet.push_back(AttributeSet::get(C, Index, B));
 
   // Add the remaining attribute slots.
   for (unsigned I = LastIndex, E = NumAttrs; I < E; ++I)
@@ -577,22 +816,21 @@ AttributeSet AttributeSet::addAttributes(LLVMContext &C, unsigned Idx,
   return get(C, AttrSet);
 }
 
-AttributeSet AttributeSet::removeAttribute(LLVMContext &C, unsigned Idx,
+AttributeSet AttributeSet::removeAttribute(LLVMContext &C, unsigned Index,
                                            Attribute::AttrKind Attr) const {
-  return removeAttributes(C, Idx, AttributeSet::get(C, Idx, Attr));
+  if (!hasAttribute(Index, Attr)) return *this;
+  return removeAttributes(C, Index, AttributeSet::get(C, Index, Attr));
 }
 
-AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Idx,
+AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Index,
                                             AttributeSet Attrs) const {
   if (!pImpl) return AttributeSet();
   if (!Attrs.pImpl) return *this;
 
-#ifndef NDEBUG
   // FIXME it is not obvious how this should work for alignment.
   // For now, say we can't pass in alignment, which no current use does.
-  assert(!Attrs.hasAttribute(Idx, Attribute::Alignment) &&
+  assert(!Attrs.hasAttribute(Index, Attribute::Alignment) &&
          "Attempt to change alignment!");
-#endif
 
   // Add the attribute slots before the one we're trying to add.
   SmallVector<AttributeSet, 4> AttrSet;
@@ -600,8 +838,8 @@ AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Idx,
   AttributeSet AS;
   uint64_t LastIndex = 0;
   for (unsigned I = 0, E = NumAttrs; I != E; ++I) {
-    if (getSlotIndex(I) >= Idx) {
-      if (getSlotIndex(I) == Idx) AS = getSlotAttributes(LastIndex++);
+    if (getSlotIndex(I) >= Index) {
+      if (getSlotIndex(I) == Index) AS = getSlotAttributes(LastIndex++);
       break;
     }
     LastIndex = I + 1;
@@ -610,15 +848,51 @@ AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Idx,
 
   // Now remove the attribute from the correct slot. There may already be an
   // AttributeSet there.
-  AttrBuilder B(AS, Idx);
+  AttrBuilder B(AS, Index);
 
   for (unsigned I = 0, E = Attrs.pImpl->getNumAttributes(); I != E; ++I)
-    if (Attrs.getSlotIndex(I) == Idx) {
-      B.removeAttributes(Attrs.pImpl->getSlotAttributes(I), Idx);
+    if (Attrs.getSlotIndex(I) == Index) {
+      B.removeAttributes(Attrs.pImpl->getSlotAttributes(I), Index);
+      break;
+    }
+
+  AttrSet.push_back(AttributeSet::get(C, Index, B));
+
+  // Add the remaining attribute slots.
+  for (unsigned I = LastIndex, E = NumAttrs; I < E; ++I)
+    AttrSet.push_back(getSlotAttributes(I));
+
+  return get(C, AttrSet);
+}
+
+AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Index,
+                                            const AttrBuilder &Attrs) const {
+  if (!pImpl) return AttributeSet();
+
+  // FIXME it is not obvious how this should work for alignment.
+  // For now, say we can't pass in alignment, which no current use does.
+  assert(!Attrs.hasAlignmentAttr() && "Attempt to change alignment!");
+
+  // Add the attribute slots before the one we're trying to add.
+  SmallVector<AttributeSet, 4> AttrSet;
+  uint64_t NumAttrs = pImpl->getNumAttributes();
+  AttributeSet AS;
+  uint64_t LastIndex = 0;
+  for (unsigned I = 0, E = NumAttrs; I != E; ++I) {
+    if (getSlotIndex(I) >= Index) {
+      if (getSlotIndex(I) == Index) AS = getSlotAttributes(LastIndex++);
       break;
     }
+    LastIndex = I + 1;
+    AttrSet.push_back(getSlotAttributes(I));
+  }
 
-  AttrSet.push_back(AttributeSet::get(C, Idx, B));
+  // Now remove the attribute from the correct slot. There may already be an
+  // AttributeSet there.
+  AttrBuilder B(AS, Index);
+  B.remove(Attrs);
+
+  AttrSet.push_back(AttributeSet::get(C, Index, B));
 
   // Add the remaining attribute slots.
   for (unsigned I = LastIndex, E = NumAttrs; I < E; ++I)
@@ -627,15 +901,34 @@ AttributeSet AttributeSet::removeAttributes(LLVMContext &C, unsigned Idx,
   return get(C, AttrSet);
 }
 
+AttributeSet AttributeSet::addDereferenceableAttr(LLVMContext &C, unsigned Index,
+                                                  uint64_t Bytes) const {
+  llvm::AttrBuilder B;
+  B.addDereferenceableAttr(Bytes);
+  return addAttributes(C, Index, AttributeSet::get(C, Index, B));
+}
+
+AttributeSet AttributeSet::addDereferenceableOrNullAttr(LLVMContext &C,
+                                                        unsigned Index,
+                                                        uint64_t Bytes) const {
+  llvm::AttrBuilder B;
+  B.addDereferenceableOrNullAttr(Bytes);
+  return addAttributes(C, Index, AttributeSet::get(C, Index, B));
+}
+
 //===----------------------------------------------------------------------===//
 // AttributeSet Accessor Methods
 //===----------------------------------------------------------------------===//
 
-AttributeSet AttributeSet::getParamAttributes(unsigned Idx) const {
-  return pImpl && hasAttributes(Idx) ?
+LLVMContext &AttributeSet::getContext() const {
+  return pImpl->getContext();
+}
+
+AttributeSet AttributeSet::getParamAttributes(unsigned Index) const {
+  return pImpl && hasAttributes(Index) ?
     AttributeSet::get(pImpl->getContext(),
                       ArrayRef<std::pair<unsigned, AttributeSetNode*> >(
-                        std::make_pair(Idx, getAttributes(Idx)))) :
+                        std::make_pair(Index, getAttributes(Index)))) :
     AttributeSet();
 }
 
@@ -662,6 +955,11 @@ bool AttributeSet::hasAttribute(unsigned Index, Attribute::AttrKind Kind) const{
   return ASN ? ASN->hasAttribute(Kind) : false;
 }
 
+bool AttributeSet::hasAttribute(unsigned Index, StringRef Kind) const {
+  AttributeSetNode *ASN = getAttributes(Index);
+  return ASN ? ASN->hasAttribute(Kind) : false;
+}
+
 bool AttributeSet::hasAttributes(unsigned Index) const {
   AttributeSetNode *ASN = getAttributes(Index);
   return ASN ? ASN->hasAttributes() : false;
@@ -670,10 +968,10 @@ bool AttributeSet::hasAttributes(unsigned Index) const {
 /// \brief Return true if the specified attribute is set for at least one
 /// parameter or for the return value.
 bool AttributeSet::hasAttrSomewhere(Attribute::AttrKind Attr) const {
-  if (pImpl == 0) return false;
+  if (!pImpl) return false;
 
   for (unsigned I = 0, E = pImpl->getNumAttributes(); I != E; ++I)
-    for (AttributeSetImpl::const_iterator II = pImpl->begin(I),
+    for (AttributeSetImpl::iterator II = pImpl->begin(I),
            IE = pImpl->end(I); II != IE; ++II)
       if (II->hasAttribute(Attr))
         return true;
@@ -681,6 +979,18 @@ bool AttributeSet::hasAttrSomewhere(Attribute::AttrKind Attr) const {
   return false;
 }
 
+Attribute AttributeSet::getAttribute(unsigned Index,
+                                     Attribute::AttrKind Kind) const {
+  AttributeSetNode *ASN = getAttributes(Index);
+  return ASN ? ASN->getAttribute(Kind) : Attribute();
+}
+
+Attribute AttributeSet::getAttribute(unsigned Index,
+                                     StringRef Kind) const {
+  AttributeSetNode *ASN = getAttributes(Index);
+  return ASN ? ASN->getAttribute(Kind) : Attribute();
+}
+
 unsigned AttributeSet::getParamAlignment(unsigned Index) const {
   AttributeSetNode *ASN = getAttributes(Index);
   return ASN ? ASN->getAlignment() : 0;
@@ -691,21 +1001,44 @@ unsigned AttributeSet::getStackAlignment(unsigned Index) const {
   return ASN ? ASN->getStackAlignment() : 0;
 }
 
-std::string AttributeSet::getAsString(unsigned Index) const {
+uint64_t AttributeSet::getDereferenceableBytes(unsigned Index) const {
+  AttributeSetNode *ASN = getAttributes(Index);
+  return ASN ? ASN->getDereferenceableBytes() : 0;
+}
+
+uint64_t AttributeSet::getDereferenceableOrNullBytes(unsigned Index) const {
+  AttributeSetNode *ASN = getAttributes(Index);
+  return ASN ? ASN->getDereferenceableOrNullBytes() : 0;
+}
+
+std::string AttributeSet::getAsString(unsigned Index,
+                                      bool InAttrGrp) const {
   AttributeSetNode *ASN = getAttributes(Index);
-  return ASN ? ASN->getAsString() : std::string("");
+  return ASN ? ASN->getAsString(InAttrGrp) : std::string("");
 }
 
 /// \brief The attributes for the specified index are returned.
-AttributeSetNode *AttributeSet::getAttributes(unsigned Idx) const {
-  if (!pImpl) return 0;
+AttributeSetNode *AttributeSet::getAttributes(unsigned Index) const {
+  if (!pImpl) return nullptr;
 
   // Loop through to find the attribute node we want.
   for (unsigned I = 0, E = pImpl->getNumAttributes(); I != E; ++I)
-    if (pImpl->getSlotIndex(I) == Idx)
+    if (pImpl->getSlotIndex(I) == Index)
       return pImpl->getSlotNode(I);
 
-  return 0;
+  return nullptr;
+}
+
+AttributeSet::iterator AttributeSet::begin(unsigned Slot) const {
+  if (!pImpl)
+    return ArrayRef<Attribute>().begin();
+  return pImpl->begin(Slot);
+}
+
+AttributeSet::iterator AttributeSet::end(unsigned Slot) const {
+  if (!pImpl)
+    return ArrayRef<Attribute>().end();
+  return pImpl->end(Slot);
 }
 
 //===----------------------------------------------------------------------===//
@@ -719,7 +1052,7 @@ unsigned AttributeSet::getNumSlots() const {
   return pImpl ? pImpl->getNumAttributes() : 0;
 }
 
-uint64_t AttributeSet::getSlotIndex(unsigned Slot) const {
+unsigned AttributeSet::getSlotIndex(unsigned Slot) const {
   assert(pImpl && Slot < pImpl->getNumAttributes() &&
          "Slot # out of range!");
   return pImpl->getSlotIndex(Slot);
@@ -756,82 +1089,128 @@ void AttributeSet::dump() const {
 // AttrBuilder Method Implementations
 //===----------------------------------------------------------------------===//
 
-AttrBuilder::AttrBuilder(AttributeSet AS, unsigned Idx)
-  : Alignment(0), StackAlignment(0) {
+AttrBuilder::AttrBuilder(AttributeSet AS, unsigned Index)
+    : Attrs(0), Alignment(0), StackAlignment(0), DerefBytes(0),
+      DerefOrNullBytes(0) {
   AttributeSetImpl *pImpl = AS.pImpl;
   if (!pImpl) return;
 
   for (unsigned I = 0, E = pImpl->getNumAttributes(); I != E; ++I) {
-    if (pImpl->getSlotIndex(I) != Idx) continue;
+    if (pImpl->getSlotIndex(I) != Index) continue;
 
-    for (AttributeSetImpl::const_iterator II = pImpl->begin(I),
+    for (AttributeSetImpl::iterator II = pImpl->begin(I),
            IE = pImpl->end(I); II != IE; ++II)
-      addAttributes(*II);
+      addAttribute(*II);
 
     break;
   }
 }
 
 void AttrBuilder::clear() {
-  Attrs.clear();
-  Alignment = StackAlignment = 0;
+  Attrs.reset();
+  Alignment = StackAlignment = DerefBytes = DerefOrNullBytes = 0;
 }
 
 AttrBuilder &AttrBuilder::addAttribute(Attribute::AttrKind Val) {
-  Attrs.insert(Val);
+  assert((unsigned)Val < Attribute::EndAttrKinds && "Attribute out of range!");
+  assert(Val != Attribute::Alignment && Val != Attribute::StackAlignment &&
+         Val != Attribute::Dereferenceable &&
+         "Adding integer attribute without adding a value!");
+  Attrs[Val] = true;
   return *this;
 }
 
-AttrBuilder &AttrBuilder::removeAttribute(Attribute::AttrKind Val) {
-  Attrs.erase(Val);
-  if (Val == Attribute::Alignment)
-    Alignment = 0;
-  else if (Val == Attribute::StackAlignment)
-    StackAlignment = 0;
+AttrBuilder &AttrBuilder::addAttribute(Attribute Attr) {
+  if (Attr.isStringAttribute()) {
+    addAttribute(Attr.getKindAsString(), Attr.getValueAsString());
+    return *this;
+  }
+
+  Attribute::AttrKind Kind = Attr.getKindAsEnum();
+  Attrs[Kind] = true;
 
+  if (Kind == Attribute::Alignment)
+    Alignment = Attr.getAlignment();
+  else if (Kind == Attribute::StackAlignment)
+    StackAlignment = Attr.getStackAlignment();
+  else if (Kind == Attribute::Dereferenceable)
+    DerefBytes = Attr.getDereferenceableBytes();
+  else if (Kind == Attribute::DereferenceableOrNull)
+    DerefOrNullBytes = Attr.getDereferenceableOrNullBytes();
   return *this;
 }
 
-AttrBuilder &AttrBuilder::addAttributes(Attribute Attr) {
-  uint64_t Mask = Attr.Raw();
+AttrBuilder &AttrBuilder::addAttribute(StringRef A, StringRef V) {
+  TargetDepAttrs[A] = V;
+  return *this;
+}
 
-  for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
-       I = Attribute::AttrKind(I + 1))
-    if ((Mask & AttributeImpl::getAttrMask(I)) != 0)
-      Attrs.insert(I);
+AttrBuilder &AttrBuilder::removeAttribute(Attribute::AttrKind Val) {
+  assert((unsigned)Val < Attribute::EndAttrKinds && "Attribute out of range!");
+  Attrs[Val] = false;
+
+  if (Val == Attribute::Alignment)
+    Alignment = 0;
+  else if (Val == Attribute::StackAlignment)
+    StackAlignment = 0;
+  else if (Val == Attribute::Dereferenceable)
+    DerefBytes = 0;
+  else if (Val == Attribute::DereferenceableOrNull)
+    DerefOrNullBytes = 0;
 
-  if (Attr.getAlignment())
-    Alignment = Attr.getAlignment();
-  if (Attr.getStackAlignment())
-    StackAlignment = Attr.getStackAlignment();
   return *this;
 }
 
 AttrBuilder &AttrBuilder::removeAttributes(AttributeSet A, uint64_t Index) {
-  uint64_t Mask = A.Raw(Index);
+  unsigned Slot = ~0U;
+  for (unsigned I = 0, E = A.getNumSlots(); I != E; ++I)
+    if (A.getSlotIndex(I) == Index) {
+      Slot = I;
+      break;
+    }
 
-  for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
-       I = Attribute::AttrKind(I + 1)) {
-    if (Mask & AttributeImpl::getAttrMask(I)) {
-      Attrs.erase(I);
+  assert(Slot != ~0U && "Couldn't find index in AttributeSet!");
 
-      if (I == Attribute::Alignment)
+  for (AttributeSet::iterator I = A.begin(Slot), E = A.end(Slot); I != E; ++I) {
+    Attribute Attr = *I;
+    if (Attr.isEnumAttribute() || Attr.isIntAttribute()) {
+      Attribute::AttrKind Kind = I->getKindAsEnum();
+      Attrs[Kind] = false;
+
+      if (Kind == Attribute::Alignment)
         Alignment = 0;
-      else if (I == Attribute::StackAlignment)
+      else if (Kind == Attribute::StackAlignment)
         StackAlignment = 0;
+      else if (Kind == Attribute::Dereferenceable)
+        DerefBytes = 0;
+      else if (Kind == Attribute::DereferenceableOrNull)
+        DerefOrNullBytes = 0;
+    } else {
+      assert(Attr.isStringAttribute() && "Invalid attribute type!");
+      std::map<std::string, std::string>::iterator
+        Iter = TargetDepAttrs.find(Attr.getKindAsString());
+      if (Iter != TargetDepAttrs.end())
+        TargetDepAttrs.erase(Iter);
     }
   }
 
   return *this;
 }
 
+AttrBuilder &AttrBuilder::removeAttribute(StringRef A) {
+  std::map<std::string, std::string>::iterator I = TargetDepAttrs.find(A);
+  if (I != TargetDepAttrs.end())
+    TargetDepAttrs.erase(I);
+  return *this;
+}
+
 AttrBuilder &AttrBuilder::addAlignmentAttr(unsigned Align) {
   if (Align == 0) return *this;
 
   assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
   assert(Align <= 0x40000000 && "Alignment too large.");
 
-  Attrs.insert(Attribute::Alignment);
+  Attrs[Attribute::Alignment] = true;
   Alignment = Align;
   return *this;
 }
@@ -843,21 +1222,116 @@ AttrBuilder &AttrBuilder::addStackAlignmentAttr(unsigned Align) {
   assert(isPowerOf2_32(Align) && "Alignment must be a power of two.");
   assert(Align <= 0x100 && "Alignment too large.");
 
-  Attrs.insert(Attribute::StackAlignment);
+  Attrs[Attribute::StackAlignment] = true;
   StackAlignment = Align;
   return *this;
 }
 
-bool AttrBuilder::contains(Attribute::AttrKind A) const {
-  return Attrs.count(A);
+AttrBuilder &AttrBuilder::addDereferenceableAttr(uint64_t Bytes) {
+  if (Bytes == 0) return *this;
+
+  Attrs[Attribute::Dereferenceable] = true;
+  DerefBytes = Bytes;
+  return *this;
+}
+
+AttrBuilder &AttrBuilder::addDereferenceableOrNullAttr(uint64_t Bytes) {
+  if (Bytes == 0)
+    return *this;
+
+  Attrs[Attribute::DereferenceableOrNull] = true;
+  DerefOrNullBytes = Bytes;
+  return *this;
+}
+
+AttrBuilder &AttrBuilder::merge(const AttrBuilder &B) {
+  // FIXME: What if both have alignments, but they don't match?!
+  if (!Alignment)
+    Alignment = B.Alignment;
+
+  if (!StackAlignment)
+    StackAlignment = B.StackAlignment;
+
+  if (!DerefBytes)
+    DerefBytes = B.DerefBytes;
+
+  if (!DerefOrNullBytes)
+    DerefOrNullBytes = B.DerefOrNullBytes;
+
+  Attrs |= B.Attrs;
+
+  for (auto I : B.td_attrs())
+    TargetDepAttrs[I.first] = I.second;
+
+  return *this;
+}
+
+AttrBuilder &AttrBuilder::remove(const AttrBuilder &B) {
+  // FIXME: What if both have alignments, but they don't match?!
+  if (B.Alignment)
+    Alignment = 0;
+
+  if (B.StackAlignment)
+    StackAlignment = 0;
+
+  if (B.DerefBytes)
+    DerefBytes = 0;
+
+  if (B.DerefOrNullBytes)
+    DerefOrNullBytes = 0;
+
+  Attrs &= ~B.Attrs;
+
+  for (auto I : B.td_attrs())
+    TargetDepAttrs.erase(I.first);
+
+  return *this;
+}
+
+bool AttrBuilder::overlaps(const AttrBuilder &B) const {
+  // First check if any of the target independent attributes overlap.
+  if ((Attrs & B.Attrs).any())
+    return true;
+
+  // Then check if any target dependent ones do.
+  for (auto I : td_attrs())
+    if (B.contains(I.first))
+      return true;
+
+  return false;
+}
+
+bool AttrBuilder::contains(StringRef A) const {
+  return TargetDepAttrs.find(A) != TargetDepAttrs.end();
 }
 
 bool AttrBuilder::hasAttributes() const {
-  return !Attrs.empty();
+  return !Attrs.none() || !TargetDepAttrs.empty();
 }
 
 bool AttrBuilder::hasAttributes(AttributeSet A, uint64_t Index) const {
-  return Raw() & A.Raw(Index);
+  unsigned Slot = ~0U;
+  for (unsigned I = 0, E = A.getNumSlots(); I != E; ++I)
+    if (A.getSlotIndex(I) == Index) {
+      Slot = I;
+      break;
+    }
+
+  assert(Slot != ~0U && "Couldn't find the index!");
+
+  for (AttributeSet::iterator I = A.begin(Slot), E = A.end(Slot);
+       I != E; ++I) {
+    Attribute Attr = *I;
+    if (Attr.isEnumAttribute() || Attr.isIntAttribute()) {
+      if (Attrs[I->getKindAsEnum()])
+        return true;
+    } else {
+      assert(Attr.isStringAttribute() && "Invalid attribute kind!");
+      return TargetDepAttrs.find(Attr.getKindAsString())!=TargetDepAttrs.end();
+    }
+  }
+
+  return false;
 }
 
 bool AttrBuilder::hasAlignmentAttr() const {
@@ -865,18 +1339,30 @@ bool AttrBuilder::hasAlignmentAttr() const {
 }
 
 bool AttrBuilder::operator==(const AttrBuilder &B) {
-  SmallVector<Attribute::AttrKind, 8> This(Attrs.begin(), Attrs.end());
-  SmallVector<Attribute::AttrKind, 8> That(B.Attrs.begin(), B.Attrs.end());
-  return This == That;
+  if (Attrs != B.Attrs)
+    return false;
+
+  for (td_const_iterator I = TargetDepAttrs.begin(),
+         E = TargetDepAttrs.end(); I != E; ++I)
+    if (B.TargetDepAttrs.find(I->first) == B.TargetDepAttrs.end())
+      return false;
+
+  return Alignment == B.Alignment && StackAlignment == B.StackAlignment &&
+         DerefBytes == B.DerefBytes;
 }
 
 AttrBuilder &AttrBuilder::addRawValue(uint64_t Val) {
+  // FIXME: Remove this in 4.0.
   if (!Val) return *this;
 
   for (Attribute::AttrKind I = Attribute::None; I != Attribute::EndAttrKinds;
        I = Attribute::AttrKind(I + 1)) {
+    if (I == Attribute::Dereferenceable ||
+        I == Attribute::DereferenceableOrNull ||
+        I == Attribute::ArgMemOnly)
+      continue;
     if (uint64_t A = (Val & AttributeImpl::getAttrMask(I))) {
-      Attrs.insert(I);
+      Attrs[I] = true;
  
       if (I == Attribute::Alignment)
         Alignment = 1ULL << ((A >> 16) - 1);
@@ -888,29 +1374,12 @@ AttrBuilder &AttrBuilder::addRawValue(uint64_t Val) {
   return *this;
 }
 
-uint64_t AttrBuilder::Raw() const {
-  uint64_t Mask = 0;
-
-  for (DenseSet<Attribute::AttrKind>::const_iterator I = Attrs.begin(),
-         E = Attrs.end(); I != E; ++I) {
-    Attribute::AttrKind Kind = *I;
-
-    if (Kind == Attribute::Alignment)
-      Mask |= (Log2_32(Alignment) + 1) << 16;
-    else if (Kind == Attribute::StackAlignment)
-      Mask |= (Log2_32(StackAlignment) + 1) << 26;
-    else
-      Mask |= AttributeImpl::getAttrMask(Kind);
-  }
-
-  return Mask;
-}
-
 //===----------------------------------------------------------------------===//
 // AttributeFuncs Function Defintions
 //===----------------------------------------------------------------------===//
 
-AttributeSet AttributeFuncs::typeIncompatible(Type *Ty, uint64_t Index) {
+/// \brief Which attributes cannot be applied to a type.
+AttrBuilder AttributeFuncs::typeIncompatible(Type *Ty) {
   AttrBuilder Incompatible;
 
   if (!Ty->isIntegerTy())
@@ -924,48 +1393,13 @@ AttributeSet AttributeFuncs::typeIncompatible(Type *Ty, uint64_t Index) {
       .addAttribute(Attribute::Nest)
       .addAttribute(Attribute::NoAlias)
       .addAttribute(Attribute::NoCapture)
-      .addAttribute(Attribute::StructRet);
-
-  return AttributeSet::get(Ty->getContext(), Index, Incompatible);
-}
-
-/// \brief This returns an integer containing an encoding of all the LLVM
-/// attributes found in the given attribute bitset.  Any change to this encoding
-/// is a breaking change to bitcode compatibility.
-/// N.B. This should be used only by the bitcode reader!
-uint64_t AttributeFuncs::encodeLLVMAttributesForBitcode(AttributeSet Attrs,
-                                                        unsigned Index) {
-  // FIXME: It doesn't make sense to store the alignment information as an
-  // expanded out value, we should store it as a log2 value.  However, we can't
-  // just change that here without breaking bitcode compatibility.  If this ever
-  // becomes a problem in practice, we should introduce new tag numbers in the
-  // bitcode file and have those tags use a more efficiently encoded alignment
-  // field.
-
-  // Store the alignment in the bitcode as a 16-bit raw value instead of a 5-bit
-  // log2 encoded value. Shift the bits above the alignment up by 11 bits.
-  uint64_t EncodedAttrs = Attrs.Raw(Index) & 0xffff;
-  if (Attrs.hasAttribute(Index, Attribute::Alignment))
-    EncodedAttrs |= Attrs.getParamAlignment(Index) << 16;
-  EncodedAttrs |= (Attrs.Raw(Index) & (0xffffULL << 21)) << 11;
-  return EncodedAttrs;
-}
-
-/// \brief This fills an AttrBuilder object with the LLVM attributes that have
-/// been decoded from the given integer. This function must stay in sync with
-/// 'encodeLLVMAttributesForBitcode'.
-/// N.B. This should be used only by the bitcode reader!
-void AttributeFuncs::decodeLLVMAttributesForBitcode(LLVMContext &C,
-                                                    AttrBuilder &B,
-                                                    uint64_t EncodedAttrs) {
-  // The alignment is stored as a 16-bit raw value from bits 31--16.  We shift
-  // the bits above 31 down by 11 bits.
-  unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
-  assert((!Alignment || isPowerOf2_32(Alignment)) &&
-         "Alignment must be a power of two.");
-
-  if (Alignment)
-    B.addAlignmentAttr(Alignment);
-  B.addRawValue(((EncodedAttrs & (0xffffULL << 32)) >> 11) |
-                (EncodedAttrs & 0xffff));
+      .addAttribute(Attribute::NonNull)
+      .addDereferenceableAttr(1) // the int here is ignored
+      .addDereferenceableOrNullAttr(1) // the int here is ignored
+      .addAttribute(Attribute::ReadNone)
+      .addAttribute(Attribute::ReadOnly)
+      .addAttribute(Attribute::StructRet)
+      .addAttribute(Attribute::InAlloca);
+
+  return Incompatible;
 }