Index: include/llvm/IR/Metadata.h
===================================================================
--- include/llvm/IR/Metadata.h
+++ include/llvm/IR/Metadata.h
@@ -964,6 +964,8 @@
   static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
   static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
   static MDNode *getMostGenericAliasScope(MDNode *A, MDNode *B);
+  static MDNode *getMostGenericAlignment(MDNode *A, MDNode *B);
+
 };
 
 /// \brief Tuple of metadata.
Index: lib/IR/Metadata.cpp
===================================================================
--- lib/IR/Metadata.cpp
+++ lib/IR/Metadata.cpp
@@ -953,6 +953,17 @@
   return MDNode::get(A->getContext(), MDs);
 }
 
+MDNode *MDNode::getMostGenericAlignment(MDNode *A, MDNode *B) {
+  if (!A || !B)
+    return nullptr;
+
+  ConstantInt *AVal = mdconst::extract<ConstantInt>(A->getOperand(0));
+  ConstantInt *BVal = mdconst::extract<ConstantInt>(B->getOperand(0));
+  if (AVal->getZExtValue() < BVal->getZExtValue())
+    return A;
+  return B;
+}
+
 //===----------------------------------------------------------------------===//
 // NamedMDNode implementation.
 //
Index: lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -373,6 +373,14 @@
       // conversions make it hard. If the new type is a pointer, we could
       // translate it to !nonnull metadata.
       break;
+    case LLVMContext::MD_align:
+    case LLVMContext::MD_dereferenceable:
+    case LLVMContext::MD_dereferenceable_or_null:
+      // These only directly apply if the new type is also a pointer.
+      if (NewTy->isPointerTy()) {
+        NewLoad->setMetadata(ID, N);
+        break;
+      }
     }
   }
   return NewLoad;
@@ -418,6 +426,9 @@
     case LLVMContext::MD_invariant_load:
     case LLVMContext::MD_nonnull:
     case LLVMContext::MD_range:
+    case LLVMContext::MD_align:
+    case LLVMContext::MD_dereferenceable:
+    case LLVMContext::MD_dereferenceable_or_null:
       // These don't apply for stores.
       break;
     }
@@ -755,10 +766,12 @@
                                DefMaxInstsToScan, AA, &AATags)) {
     if (LoadInst *NLI = dyn_cast<LoadInst>(AvailableVal)) {
       unsigned KnownIDs[] = {
-          LLVMContext::MD_tbaa,           LLVMContext::MD_alias_scope,
-          LLVMContext::MD_noalias,        LLVMContext::MD_range,
-          LLVMContext::MD_invariant_load, LLVMContext::MD_nonnull,
-          LLVMContext::MD_invariant_group};
+          LLVMContext::MD_tbaa,            LLVMContext::MD_alias_scope,
+          LLVMContext::MD_noalias,         LLVMContext::MD_range,
+          LLVMContext::MD_invariant_load,  LLVMContext::MD_nonnull,
+          LLVMContext::MD_invariant_group, LLVMContext::MD_align,
+          LLVMContext::MD_dereferenceable,
+          LLVMContext::MD_dereferenceable_or_null};
       combineMetadata(NLI, &LI, KnownIDs);
     };
 
Index: lib/Transforms/InstCombine/InstCombinePHI.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombinePHI.cpp
+++ lib/Transforms/InstCombine/InstCombinePHI.cpp
@@ -358,7 +358,10 @@
     LLVMContext::MD_invariant_load,
     LLVMContext::MD_alias_scope,
     LLVMContext::MD_noalias,
-    LLVMContext::MD_nonnull
+    LLVMContext::MD_nonnull,
+    LLVMContext::MD_align,
+    LLVMContext::MD_dereferenceable,
+    LLVMContext::MD_dereferenceable_or_null,
   };
 
   for (unsigned ID : KnownIDs)
Index: lib/Transforms/Utils/Local.cpp
===================================================================
--- lib/Transforms/Utils/Local.cpp
+++ lib/Transforms/Utils/Local.cpp
@@ -1420,16 +1420,18 @@
         K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD));
         break;
       case LLVMContext::MD_invariant_load:
-        // Only set the !invariant.load if it is present in both instructions.
-        K->setMetadata(Kind, JMD);
-        break;
       case LLVMContext::MD_nonnull:
-        // Only set the !nonnull if it is present in both instructions.
+      case LLVMContext::MD_dereferenceable:
+      case LLVMContext::MD_dereferenceable_or_null:
+        // Only set if it is present in both instructions.
         K->setMetadata(Kind, JMD);
         break;
       case LLVMContext::MD_invariant_group:
         // Preserve !invariant.group in K.
         break;
+      case LLVMContext::MD_align:
+        K->setMetadata(Kind, MDNode::getMostGenericAlignment(JMD, KMD));
+        break;
     }
   }
   // Set !invariant.group from J if J has it. If both instructions have it
Index: lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyCFG.cpp
+++ lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1097,7 +1097,9 @@
     unsigned KnownIDs[] = {
         LLVMContext::MD_tbaa,    LLVMContext::MD_range,
         LLVMContext::MD_fpmath,  LLVMContext::MD_invariant_load,
-        LLVMContext::MD_nonnull, LLVMContext::MD_invariant_group};
+        LLVMContext::MD_nonnull, LLVMContext::MD_invariant_group,
+        LLVMContext::MD_align,   LLVMContext::MD_dereferenceable,
+        LLVMContext::MD_dereferenceable_or_null};
     combineMetadata(I1, I2, KnownIDs);
     I2->eraseFromParent();
     Changed = true;