diff --git a/include/llvm/IR/Attributes.h b/include/llvm/IR/Attributes.h
index 6436ee0..1fe1b21 100644
--- a/include/llvm/IR/Attributes.h
+++ b/include/llvm/IR/Attributes.h
@@ -151,11 +151,11 @@
 
   /// Returns the alignment field of an attribute as a byte alignment
   /// value.
-  unsigned getAlignment() const;
+  MaybeAlign getAlignment() const;
 
   /// Returns the stack alignment field of an attribute as a byte
   /// alignment value.
-  unsigned getStackAlignment() const;
+  MaybeAlign getStackAlignment() const;
 
   /// Returns the number of dereferenceable bytes from the
   /// dereferenceable attribute.
@@ -285,8 +285,8 @@
   /// Return the target-dependent attribute object.
   Attribute getAttribute(StringRef Kind) const;
 
-  unsigned getAlignment() const;
-  unsigned getStackAlignment() const;
+  MaybeAlign getAlignment() const;
+  MaybeAlign getStackAlignment() const;
   uint64_t getDereferenceableBytes() const;
   uint64_t getDereferenceableOrNullBytes() const;
   Type *getByValType() const;
@@ -604,16 +604,16 @@
   }
 
   /// Return the alignment of the return value.
-  unsigned getRetAlignment() const;
+  MaybeAlign getRetAlignment() const;
 
   /// Return the alignment for the specified function parameter.
-  unsigned getParamAlignment(unsigned ArgNo) const;
+  MaybeAlign getParamAlignment(unsigned ArgNo) const;
 
   /// Return the byval type for the specified function parameter.
   Type *getParamByValType(unsigned ArgNo) const;
 
   /// Get the stack alignment.
-  unsigned getStackAlignment(unsigned Index) const;
+  MaybeAlign getStackAlignment(unsigned Index) const;
 
   /// Get the number of dereferenceable bytes (or zero if unknown).
   uint64_t getDereferenceableBytes(unsigned Index) const;
@@ -796,13 +796,29 @@
   /// doesn't exist, pair(0, 0) is returned.
   std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
 
+  /// This turns an alignment into the form used internally in Attribute.
+  /// This call has no effect if Align is not set.
+  AttrBuilder &addAlignmentAttr(MaybeAlign Align);
+
   /// This turns an int alignment (which must be a power of 2) into the
   /// form used internally in Attribute.
-  AttrBuilder &addAlignmentAttr(unsigned Align);
+  /// This call has no effect if Align is 0.
+  /// Deprecated, use the version using a MaybeAlign.
+  inline AttrBuilder &addAlignmentAttr(unsigned Align) {
+    return addAlignmentAttr(MaybeAlign(Align));
+  }
+
+  /// This turns a stack alignment into the form used internally in Attribute.
+  /// This call has no effect if Align is not set.
+  AttrBuilder &addStackAlignmentAttr(MaybeAlign Align);
 
   /// This turns an int stack alignment (which must be a power of 2) into
   /// the form used internally in Attribute.
-  AttrBuilder &addStackAlignmentAttr(unsigned Align);
+  /// This call has no effect if Align is 0.
+  /// Deprecated, use the version using a MaybeAlign.
+  inline AttrBuilder &addStackAlignmentAttr(unsigned Align) {
+    return addStackAlignmentAttr(MaybeAlign(Align));
+  }
 
   /// This turns the number of dereferenceable bytes into the form used
   /// internally in Attribute.
diff --git a/include/llvm/IR/Function.h b/include/llvm/IR/Function.h
index cee8d6c..d586a94 100644
--- a/include/llvm/IR/Function.h
+++ b/include/llvm/IR/Function.h
@@ -343,7 +343,10 @@
   unsigned getFnStackAlignment() const {
     if (!hasFnAttribute(Attribute::StackAlignment))
       return 0;
-    return AttributeSets.getStackAlignment(AttributeList::FunctionIndex);
+    if (const auto MA =
+            AttributeSets.getStackAlignment(AttributeList::FunctionIndex))
+      return MA->value();
+    return 0;
   }
 
   /// hasGC/getGC/setGC/clearGC - The name of the garbage collection algorithm
@@ -433,7 +436,9 @@
 
   /// Extract the alignment for a call or parameter (0=unknown).
   unsigned getParamAlignment(unsigned ArgNo) const {
-    return AttributeSets.getParamAlignment(ArgNo);
+    if (const auto MA = AttributeSets.getParamAlignment(ArgNo))
+      return MA->value();
+    return 0;
   }
 
   /// Extract the byval type for a parameter.
diff --git a/include/llvm/IR/InstrTypes.h b/include/llvm/IR/InstrTypes.h
index 3c5051d..7fb94e9 100644
--- a/include/llvm/IR/InstrTypes.h
+++ b/include/llvm/IR/InstrTypes.h
@@ -1567,11 +1567,17 @@
   }
 
   /// Extract the alignment of the return value.
-  unsigned getRetAlignment() const { return Attrs.getRetAlignment(); }
+  unsigned getRetAlignment() const {
+    if (const auto MA = Attrs.getRetAlignment())
+      return MA->value();
+    return 0;
+  }
 
   /// Extract the alignment for a call or parameter (0=unknown).
   unsigned getParamAlignment(unsigned ArgNo) const {
-    return Attrs.getParamAlignment(ArgNo);
+    if (const auto MA = Attrs.getParamAlignment(ArgNo))
+      return MA->value();
+    return 0;
   }
 
   /// Extract the byval type for a call or parameter.
diff --git a/lib/IR/AttributeImpl.h b/lib/IR/AttributeImpl.h
index 54e4463..15e488b 100644
--- a/lib/IR/AttributeImpl.h
+++ b/lib/IR/AttributeImpl.h
@@ -208,8 +208,8 @@
   Attribute getAttribute(Attribute::AttrKind Kind) const;
   Attribute getAttribute(StringRef Kind) const;
 
-  unsigned getAlignment() const;
-  unsigned getStackAlignment() const;
+  MaybeAlign getAlignment() const;
+  MaybeAlign getStackAlignment() const;
   uint64_t getDereferenceableBytes() const;
   uint64_t getDereferenceableOrNullBytes() const;
   std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
diff --git a/lib/IR/Attributes.cpp b/lib/IR/Attributes.cpp
index dda70f4..5b7b8b8 100644
--- a/lib/IR/Attributes.cpp
+++ b/lib/IR/Attributes.cpp
@@ -241,16 +241,16 @@
   return pImpl && pImpl->hasAttribute(Kind);
 }
 
-unsigned Attribute::getAlignment() const {
+MaybeAlign Attribute::getAlignment() const {
   assert(hasAttribute(Attribute::Alignment) &&
          "Trying to get alignment from non-alignment attribute!");
-  return pImpl->getValueAsInt();
+  return MaybeAlign(pImpl->getValueAsInt());
 }
 
-unsigned Attribute::getStackAlignment() const {
+MaybeAlign Attribute::getStackAlignment() const {
   assert(hasAttribute(Attribute::StackAlignment) &&
          "Trying to get alignment from non-alignment attribute!");
-  return pImpl->getValueAsInt();
+  return MaybeAlign(pImpl->getValueAsInt());
 }
 
 uint64_t Attribute::getDereferenceableBytes() const {
@@ -667,12 +667,12 @@
   return SetNode ? SetNode->getAttribute(Kind) : Attribute();
 }
 
-unsigned AttributeSet::getAlignment() const {
-  return SetNode ? SetNode->getAlignment() : 0;
+MaybeAlign AttributeSet::getAlignment() const {
+  return SetNode ? SetNode->getAlignment() : None;
 }
 
-unsigned AttributeSet::getStackAlignment() const {
-  return SetNode ? SetNode->getStackAlignment() : 0;
+MaybeAlign AttributeSet::getStackAlignment() const {
+  return SetNode ? SetNode->getStackAlignment() : None;
 }
 
 uint64_t AttributeSet::getDereferenceableBytes() const {
@@ -833,18 +833,18 @@
   return {};
 }
 
-unsigned AttributeSetNode::getAlignment() const {
+MaybeAlign AttributeSetNode::getAlignment() const {
   for (const auto I : *this)
     if (I.hasAttribute(Attribute::Alignment))
       return I.getAlignment();
-  return 0;
+  return None;
 }
 
-unsigned AttributeSetNode::getStackAlignment() const {
+MaybeAlign AttributeSetNode::getStackAlignment() const {
   for (const auto I : *this)
     if (I.hasAttribute(Attribute::StackAlignment))
       return I.getStackAlignment();
-  return 0;
+  return None;
 }
 
 Type *AttributeSetNode::getByValType() const {
@@ -1161,7 +1161,7 @@
 #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 = getAttributes(Index).getAlignment();
+  const MaybeAlign OldAlign = getAttributes(Index).getAlignment();
   unsigned NewAlign = B.getAlignment();
   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
          "Attempt to change alignment!");
@@ -1346,11 +1346,11 @@
   return getAttributes(Index).getAttribute(Kind);
 }
 
-unsigned AttributeList::getRetAlignment() const {
+MaybeAlign AttributeList::getRetAlignment() const {
   return getAttributes(ReturnIndex).getAlignment();
 }
 
-unsigned AttributeList::getParamAlignment(unsigned ArgNo) const {
+MaybeAlign AttributeList::getParamAlignment(unsigned ArgNo) const {
   return getAttributes(ArgNo + FirstArgIndex).getAlignment();
 }
 
@@ -1358,8 +1358,7 @@
   return getAttributes(Index+FirstArgIndex).getByValType();
 }
 
-
-unsigned AttributeList::getStackAlignment(unsigned Index) const {
+MaybeAlign AttributeList::getStackAlignment(unsigned Index) const {
   return getAttributes(Index).getStackAlignment();
 }
 
@@ -1516,8 +1515,7 @@
   return unpackAllocSizeArgs(AllocSizeArgs);
 }
 
-AttrBuilder &AttrBuilder::addAlignmentAttr(unsigned A) {
-  MaybeAlign Align(A);
+AttrBuilder &AttrBuilder::addAlignmentAttr(MaybeAlign Align) {
   if (!Align)
     return *this;
 
@@ -1528,8 +1526,7 @@
   return *this;
 }
 
-AttrBuilder &AttrBuilder::addStackAlignmentAttr(unsigned A) {
-  MaybeAlign Align(A);
+AttrBuilder &AttrBuilder::addStackAlignmentAttr(MaybeAlign Align) {
   // Default alignment, allow the target to define how to align it.
   if (!Align)
     return *this;
diff --git a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
index 3a45085..307f4d5 100644
--- a/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
+++ b/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
@@ -1473,12 +1473,11 @@
         // Just print .param .align <a> .b8 .param[size];
         // <a> = PAL.getparamalignment
         // size = typeallocsize of element type
-        unsigned align = PAL.getParamAlignment(paramIndex);
-        if (align == 0)
-          align = DL.getABITypeAlignment(Ty);
+        const Align align = DL.getValueOrABITypeAlignment(
+            PAL.getParamAlignment(paramIndex), Ty);
 
         unsigned sz = DL.getTypeAllocSize(Ty);
-        O << "\t.param .align " << align << " .b8 ";
+        O << "\t.param .align " << align.value() << " .b8 ";
         printParamName(I, paramIndex, O);
         O << "[" << sz << "]";
 
@@ -1559,9 +1558,8 @@
       // Just print .param .align <a> .b8 .param[size];
       // <a> = PAL.getparamalignment
       // size = typeallocsize of element type
-      unsigned align = PAL.getParamAlignment(paramIndex);
-      if (align == 0)
-        align = DL.getABITypeAlignment(ETy);
+      Align align =
+          DL.getValueOrABITypeAlignment(PAL.getParamAlignment(paramIndex), ETy);
       // Work around a bug in ptxas. When PTX code takes address of
       // byval parameter with alignment < 4, ptxas generates code to
       // spill argument into memory. Alas on sm_50+ ptxas generates
@@ -1573,10 +1571,10 @@
       // TODO: this will need to be undone when we get to support multi-TU
       // device-side compilation as it breaks ABI compatibility with nvcc.
       // Hopefully ptxas bug is fixed by then.
-      if (!isKernelFunc && align < 4)
-        align = 4;
+      if (!isKernelFunc && align < Align(4))
+        align = Align(4);
       unsigned sz = DL.getTypeAllocSize(ETy);
-      O << "\t.param .align " << align << " .b8 ";
+      O << "\t.param .align " << align.value() << " .b8 ";
       printParamName(I, paramIndex, O);
       O << "[" << sz << "]";
       continue;
diff --git a/unittests/IR/AttributesTest.cpp b/unittests/IR/AttributesTest.cpp
index 60708c4..b1c455e 100644
--- a/unittests/IR/AttributesTest.cpp
+++ b/unittests/IR/AttributesTest.cpp
@@ -144,15 +144,15 @@
                        Attribute::getWithAlignment(C, Align(8)));
   AL = AL.addAttribute(C, AttributeList::FirstArgIndex + 1,
                        Attribute::getWithAlignment(C, Align(32)));
-  EXPECT_EQ(8U, AL.getParamAlignment(0));
-  EXPECT_EQ(32U, AL.getParamAlignment(1));
+  EXPECT_EQ(Align(8), AL.getParamAlignment(0));
+  EXPECT_EQ(Align(32), AL.getParamAlignment(1));
 
   AttrBuilder B;
   B.addAttribute(Attribute::NonNull);
   B.addAlignmentAttr(8);
   AL = AL.addAttributes(C, AttributeList::FirstArgIndex, B);
-  EXPECT_EQ(8U, AL.getParamAlignment(0));
-  EXPECT_EQ(32U, AL.getParamAlignment(1));
+  EXPECT_EQ(Align(8), AL.getParamAlignment(0));
+  EXPECT_EQ(Align(32), AL.getParamAlignment(1));
   EXPECT_TRUE(AL.hasParamAttribute(0, Attribute::NonNull));
 }