diff --git a/mlir/include/mlir/IR/Attributes.h b/mlir/include/mlir/IR/Attributes.h
index 7c3039742c83..9496a35eae2d 100644
--- a/mlir/include/mlir/IR/Attributes.h
+++ b/mlir/include/mlir/IR/Attributes.h
@@ -144,14 +144,17 @@ public:
 class IntegerAttr : public Attribute {
 public:
   using ImplType = detail::IntegerAttributeStorage;
-  using ValueType = int64_t;
+  using ValueType = APInt;
 
   IntegerAttr() = default;
   /* implicit */ IntegerAttr(Attribute::ImplType *ptr);
 
   static IntegerAttr get(int64_t value, MLIRContext *context);
+  static IntegerAttr get(const APInt &value, MLIRContext *context);
 
-  int64_t getValue() const;
+  APInt getValue() const;
+  // TODO(jpienaar): Change callers to use getValue instead.
+  int64_t getInt() const;
 
   /// Methods for support type inquiry through isa, cast, and dyn_cast.
   static bool kindof(Kind kind) { return kind == Kind::Integer; }
diff --git a/mlir/include/mlir/IR/BuiltinOps.h b/mlir/include/mlir/IR/BuiltinOps.h
index 5d810a91e4e7..43607f9db213 100644
--- a/mlir/include/mlir/IR/BuiltinOps.h
+++ b/mlir/include/mlir/IR/BuiltinOps.h
@@ -153,7 +153,7 @@ public:
                     Type type);
 
   int64_t getValue() const {
-    return getAttrOfType<IntegerAttr>("value").getValue();
+    return getAttrOfType<IntegerAttr>("value").getInt();
   }
 
   static bool isClassFor(const Operation *op);
@@ -174,7 +174,7 @@ public:
   static void build(Builder *builder, OperationState *result, int64_t value);
 
   int64_t getValue() const {
-    return getAttrOfType<IntegerAttr>("value").getValue();
+    return getAttrOfType<IntegerAttr>("value").getInt();
   }
 
   static bool isClassFor(const Operation *op);
diff --git a/mlir/include/mlir/IR/Matchers.h b/mlir/include/mlir/IR/Matchers.h
index ad97dd2865cb..1b6ccb25b643 100644
--- a/mlir/include/mlir/IR/Matchers.h
+++ b/mlir/include/mlir/IR/Matchers.h
@@ -90,10 +90,9 @@ struct constant_int_op_binder {
 
 // The matcher that matches a given target constant scalar / vector splat /
 // tensor splat integer value.
-template <IntegerAttr::ValueType TargetValue>
-struct constant_int_value_matcher {
+template <int64_t TargetValue> struct constant_int_value_matcher {
   bool match(Operation *op) {
-    IntegerAttr::ValueType value;
+    APInt value;
 
     return constant_int_op_binder(&value).match(op) && TargetValue == value;
   }
diff --git a/mlir/include/mlir/IR/op_base.td b/mlir/include/mlir/IR/op_base.td
index 832d1f1863aa..0c6b45b6adf7 100644
--- a/mlir/include/mlir/IR/op_base.td
+++ b/mlir/include/mlir/IR/op_base.td
@@ -85,6 +85,7 @@ class F32Attr : Attr<F32> {
 class I32Attr : Attr<I<32>> {
  let storageType = [{ IntegerAttr }];
  let returnType = [{ int }];
+ let convertFromStorage = [{ return {0}.getSExtValue(); }];
 }
 
 // Class representing a Trait (defined in a C++ file that needs to be included
diff --git a/mlir/include/mlir/StandardOps/StandardOps.h b/mlir/include/mlir/StandardOps/StandardOps.h
index 173e7c88ca5c..44ab4d7f8f48 100644
--- a/mlir/include/mlir/StandardOps/StandardOps.h
+++ b/mlir/include/mlir/StandardOps/StandardOps.h
@@ -226,7 +226,7 @@ class CmpIOp : public Op<CmpIOp, OpTrait::OperandsAreIntegerLike,
 public:
   CmpIPredicate getPredicate() const {
     return (CmpIPredicate)getAttrOfType<IntegerAttr>(getPredicateAttrName())
-        .getValue();
+        .getInt();
   }
 
   static StringRef getOperationName() { return "cmpi"; }
@@ -293,8 +293,7 @@ public:
 
   /// This returns the dimension number that the 'dim' is inspecting.
   unsigned getIndex() const {
-    return static_cast<unsigned>(
-        getAttrOfType<IntegerAttr>("index").getValue());
+    return getAttrOfType<IntegerAttr>("index").getValue().getZExtValue();
   }
 
   static StringRef getOperationName() { return "dim"; }
diff --git a/mlir/lib/IR/AffineMap.cpp b/mlir/lib/IR/AffineMap.cpp
index 8acea85f01ad..27ee5ff80efa 100644
--- a/mlir/lib/IR/AffineMap.cpp
+++ b/mlir/lib/IR/AffineMap.cpp
@@ -68,6 +68,7 @@ public:
   }
 
 private:
+  // TODO: Change these to operate on APInts too.
   IntegerAttr
   constantFoldBinExpr(AffineExpr expr,
                       std::function<uint64_t(int64_t, uint64_t)> op) {
@@ -76,8 +77,7 @@ private:
     auto rhs = constantFold(binOpExpr.getRHS());
     if (!lhs || !rhs)
       return nullptr;
-    return IntegerAttr::get(op(lhs.getValue(), rhs.getValue()),
-                            expr.getContext());
+    return IntegerAttr::get(op(lhs.getInt(), rhs.getInt()), expr.getContext());
   }
 
   // The number of dimension operands in AffineMap containing this expression.
diff --git a/mlir/lib/IR/AttributeDetail.h b/mlir/lib/IR/AttributeDetail.h
index 63ad544fa482..bf0baef503be 100644
--- a/mlir/lib/IR/AttributeDetail.h
+++ b/mlir/lib/IR/AttributeDetail.h
@@ -46,8 +46,17 @@ struct BoolAttributeStorage : public AttributeStorage {
 };
 
 /// An attribute representing a integral value.
-struct IntegerAttributeStorage : public AttributeStorage {
-  int64_t value;
+struct IntegerAttributeStorage final
+    : public AttributeStorage,
+      public llvm::TrailingObjects<IntegerAttributeStorage, uint64_t> {
+  const unsigned numBits;
+  size_t numObjects;
+
+  /// Returns an APInt representing the stored value.
+  APInt getValue() const {
+    auto val = APInt(numBits, {getTrailingObjects<uint64_t>(), numObjects});
+    return val;
+  }
 };
 
 /// An attribute representing a floating point value.
diff --git a/mlir/lib/IR/Attributes.cpp b/mlir/lib/IR/Attributes.cpp
index 58b5b90d43d9..ee8aa250edee 100644
--- a/mlir/lib/IR/Attributes.cpp
+++ b/mlir/lib/IR/Attributes.cpp
@@ -37,10 +37,12 @@ bool BoolAttr::getValue() const { return static_cast<ImplType *>(attr)->value; }
 
 IntegerAttr::IntegerAttr(Attribute::ImplType *ptr) : Attribute(ptr) {}
 
-int64_t IntegerAttr::getValue() const {
-  return static_cast<ImplType *>(attr)->value;
+APInt IntegerAttr::getValue() const {
+  return static_cast<ImplType *>(attr)->getValue();
 }
 
+int64_t IntegerAttr::getInt() const { return getValue().getSExtValue(); }
+
 FloatAttr::FloatAttr(Attribute::ImplType *ptr) : Attribute(ptr) {}
 
 APFloat FloatAttr::getValue() const {
diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
index 0b461d198139..a431b0cae049 100644
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -187,6 +187,21 @@ struct FloatAttrKeyInfo : DenseMapInfo<FloatAttributeStorage *> {
   }
 };
 
+struct IntegerAttrKeyInfo : DenseMapInfo<IntegerAttributeStorage *> {
+  // Integer attributes are uniqued based on wrapped APInt.
+  using KeyTy = APInt;
+  using DenseMapInfo<IntegerAttributeStorage *>::getHashValue;
+  using DenseMapInfo<IntegerAttributeStorage *>::isEqual;
+
+  static unsigned getHashValue(KeyTy key) { return llvm::hash_value(key); }
+
+  static bool isEqual(const KeyTy &lhs, const IntegerAttributeStorage *rhs) {
+    if (rhs == getEmptyKey() || rhs == getTombstoneKey())
+      return false;
+    return lhs == rhs->getValue();
+  }
+};
+
 struct ArrayAttrKeyInfo : DenseMapInfo<ArrayAttributeStorage *> {
   // Array attributes are uniqued based on their elements.
   using KeyTy = ArrayRef<Attribute>;
@@ -377,7 +392,7 @@ public:
 
   // Attribute uniquing.
   BoolAttributeStorage *boolAttrs[2] = {nullptr};
-  DenseMap<int64_t, IntegerAttributeStorage *> integerAttrs;
+  DenseSet<IntegerAttributeStorage *, IntegerAttrKeyInfo> integerAttrs;
   DenseSet<FloatAttributeStorage *, FloatAttrKeyInfo> floatAttrs;
   StringMap<StringAttributeStorage *> stringAttrs;
   using ArrayAttrSet = DenseSet<ArrayAttributeStorage *, ArrayAttrKeyInfo>;
@@ -1040,17 +1055,37 @@ BoolAttr BoolAttr::get(bool value, MLIRContext *context) {
   return result;
 }
 
-IntegerAttr IntegerAttr::get(int64_t value, MLIRContext *context) {
-  auto *&result = context->getImpl().integerAttrs[value];
-  if (result)
-    return result;
+IntegerAttr IntegerAttr::get(const APInt &value, MLIRContext *context) {
+  auto &impl = context->getImpl();
 
-  result = context->getImpl().allocator.Allocate<IntegerAttributeStorage>();
-  new (result) IntegerAttributeStorage{{Attribute::Kind::Integer,
-                                        /*isOrContainsFunction=*/false},
-                                       value};
-  result->value = value;
-  return result;
+  // Look to see if the integer attribute has been created already.
+  auto existing = impl.integerAttrs.insert_as(nullptr, value);
+
+  // If it has been created, return it.
+  if (!existing.second)
+    return *existing.first;
+
+  // If it doesn't, create one and return it.
+  auto elements = ArrayRef<uint64_t>(value.getRawData(), value.getNumWords());
+
+  auto byteSize =
+      IntegerAttributeStorage::totalSizeToAlloc<uint64_t>(elements.size());
+  auto rawMem =
+      impl.allocator.Allocate(byteSize, alignof(IntegerAttributeStorage));
+  // TODO: This uses 64 bit APInts by default without consideration of value.
+  auto result = ::new (rawMem) IntegerAttributeStorage{
+      {Attribute::Kind::Integer, /*isOrContainsFunction=*/false},
+      {},
+      /*numBits*/ 64,
+      elements.size()};
+  std::uninitialized_copy(elements.begin(), elements.end(),
+                          result->getTrailingObjects<uint64_t>());
+  return *existing.first = result;
+}
+
+IntegerAttr IntegerAttr::get(int64_t value, MLIRContext *context) {
+  // TODO: This uses 64 bit APInts by default.
+  return get(APInt(64, value, /*isSigned=*/true), context);
 }
 
 FloatAttr FloatAttr::get(double value, MLIRContext *context) {
diff --git a/mlir/lib/Parser/Parser.cpp b/mlir/lib/Parser/Parser.cpp
index 359ac5a55c22..d65b5ba97d35 100644
--- a/mlir/lib/Parser/Parser.cpp
+++ b/mlir/lib/Parser/Parser.cpp
@@ -700,13 +700,10 @@ TensorLiteralParser::parseElementOrList(llvm::SmallVectorImpl<int> &dims) {
       if (!result.isa<IntegerAttr>())
         return p.emitError("expected tensor literal element has integer type");
       auto value = result.cast<IntegerAttr>().getValue();
-      // If we couldn't successfully round trip the value, it means some bits
-      // are truncated and we should give up here.
-      llvm::APInt apint(bitsWidth, (uint64_t)value, /*isSigned=*/true);
-      if (apint.getSExtValue() != value)
+      if (value.getMinSignedBits() > bitsWidth)
         return p.emitError("tensor literal element has more bits than that "
                            "specified in the type");
-      addToStorage((uint64_t)value);
+      addToStorage(value.getSExtValue());
       break;
     }
     default:
diff --git a/mlir/lib/StandardOps/StandardOps.cpp b/mlir/lib/StandardOps/StandardOps.cpp
index 10f62548abbf..2426dfa7d05a 100644
--- a/mlir/lib/StandardOps/StandardOps.cpp
+++ b/mlir/lib/StandardOps/StandardOps.cpp
@@ -538,8 +538,8 @@ bool CmpIOp::parse(OpAsmParser *parser, OperationState *result) {
 void CmpIOp::print(OpAsmPrinter *p) const {
   *p << getOperationName() << " ";
 
-  int predicateValue =
-      getAttrOfType<IntegerAttr>(getPredicateAttrName()).getValue();
+  auto predicateValue =
+      getAttrOfType<IntegerAttr>(getPredicateAttrName()).getInt();
   assert(predicateValue >= static_cast<int>(CmpIPredicate::FirstValidValue) &&
          predicateValue < static_cast<int>(CmpIPredicate::NumPredicates) &&
          "unknown predicate index");
@@ -561,7 +561,7 @@ bool CmpIOp::verify() const {
   auto predicateAttr = getAttrOfType<IntegerAttr>(getPredicateAttrName());
   if (!predicateAttr)
     return emitOpError("requires an integer attribute named 'predicate'");
-  auto predicate = predicateAttr.getValue();
+  auto predicate = predicateAttr.getInt();
   if (predicate < (int64_t)CmpIPredicate::FirstValidValue ||
       predicate >= (int64_t)CmpIPredicate::NumPredicates)
     return emitOpError("'predicate' attribute value out of range");
@@ -645,7 +645,7 @@ bool DimOp::verify() const {
   auto indexAttr = getAttrOfType<IntegerAttr>("index");
   if (!indexAttr)
     return emitOpError("requires an integer attribute named 'index'");
-  uint64_t index = (uint64_t)indexAttr.getValue();
+  uint64_t index = indexAttr.getValue().getZExtValue();
 
   auto type = getOperand()->getType();
   if (auto tensorType = type.dyn_cast<RankedTensorType>()) {
diff --git a/mlir/lib/Transforms/Utils/Utils.cpp b/mlir/lib/Transforms/Utils/Utils.cpp
index c1ba21f156bf..42b8a61f916b 100644
--- a/mlir/lib/Transforms/Utils/Utils.cpp
+++ b/mlir/lib/Transforms/Utils/Utils.cpp
@@ -380,11 +380,11 @@ bool mlir::constantFoldBounds(ForStmt *forStmt) {
     auto maxOrMin = foldedResults[0].cast<IntegerAttr>().getValue();
     for (unsigned i = 1; i < foldedResults.size(); i++) {
       auto foldedResult = foldedResults[i].cast<IntegerAttr>().getValue();
-      maxOrMin = lower ? std::max(maxOrMin, foldedResult)
-                       : std::min(maxOrMin, foldedResult);
+      maxOrMin = lower ? llvm::APIntOps::smax(maxOrMin, foldedResult)
+                       : llvm::APIntOps::smin(maxOrMin, foldedResult);
     }
-    lower ? forStmt->setConstantLowerBound(maxOrMin)
-          : forStmt->setConstantUpperBound(maxOrMin);
+    lower ? forStmt->setConstantLowerBound(maxOrMin.getSExtValue())
+          : forStmt->setConstantUpperBound(maxOrMin.getSExtValue());
 
     // Return false on success.
     return false;