Index: lib/Transforms/Scalar/SROA.cpp
===================================================================
--- lib/Transforms/Scalar/SROA.cpp
+++ lib/Transforms/Scalar/SROA.cpp
@@ -2387,6 +2387,21 @@
                                               LI.isVolatile(), LI.getName());
       if (LI.isVolatile())
         NewLI->setAtomic(LI.getOrdering(), LI.getSynchScope());
+
+      SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
+      LI.getAllMetadata(MD);
+      // Try to preserve as much metadata as possible
+      for (const auto &MDPair : MD) {
+          unsigned ID = MDPair.first;
+          MDNode *N = MDPair.second;
+          switch (ID) {
+          case LLVMContext::MD_nonnull:
+              if (TargetTy->isPointerTy()) {
+                NewLI->setMetadata(ID, N);
+                break;
+              }
+          }
+      }
       V = NewLI;
 
       // If this is an integer load past the end of the slice (which means the
Index: lib/Transforms/Utils/PromoteMemoryToRegister.cpp
===================================================================
--- lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -387,6 +387,25 @@
     // code.
     if (ReplVal == LI)
       ReplVal = UndefValue::get(LI->getType());
+
+    // We're replacing this Load with another Load, so let's preserve metadata
+    if (isa<LoadInst>(ReplVal)) {
+      SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
+      LI->getAllMetadata(MD);
+      // Try to preserve as much metadata as possible
+      for (const auto &MDPair : MD) {
+        unsigned ID = MDPair.first;
+        MDNode *N = MDPair.second;
+        switch (ID) {
+        case LLVMContext::MD_nonnull:
+          if (LI->getType()->isPointerTy()) {
+            ((LoadInst *) ReplVal)->setMetadata(ID, N);
+            break;
+          }
+        }
+      }
+    }
+
     LI->replaceAllUsesWith(ReplVal);
     if (AST && LI->getType()->isPointerTy())
       AST->deleteValue(LI);
@@ -939,6 +958,22 @@
         continue;
 
       Value *V = IncomingVals[AI->second];
+      if (isa<LoadInst>(V)) {
+        SmallVector<std::pair<unsigned, MDNode *>, 8> MD;
+        LI->getAllMetadata(MD);
+        // Try to preserve as much metadata as possible
+        for (const auto &MDPair : MD) {
+          unsigned ID = MDPair.first;
+          MDNode *N = MDPair.second;
+          switch (ID) {
+          case LLVMContext::MD_nonnull:
+            if (LI->getType()->isPointerTy()) {
+              ((LoadInst *) V)->setMetadata(ID, N);
+              break;
+            }
+          }
+        }
+      }
 
       // Anything using the load now uses the current value.
       LI->replaceAllUsesWith(V);
Index: test/Transforms/SROA/preserve-nonnull.ll
===================================================================
--- /dev/null
+++ test/Transforms/SROA/preserve-nonnull.ll
@@ -0,0 +1,26 @@
+; RUN: opt < %s -sroa -S | FileCheck %s
+;
+; Make sure that SROA doesn't lose nonnull metadata
+; on loads from allocas that optimized out.
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: yummy_nonnull
+; CHECK: %{{.*}} = load float*, float** %0, align 8, !nonnull !0
+
+define float* @yummy_nonnull(float**) {
+entry-block:
+	%buf = alloca float*
+
+	%_0_i8 = bitcast float** %0 to i8*
+	%_buf_i8 = bitcast float** %buf to i8*
+	call void @llvm.memcpy.p0i8.p0i8.i64(i8* %_buf_i8, i8* %_0_i8, i64 8, i32 8, i1 false)
+
+	%ret = load float*, float** %buf, align 8, !nonnull !0
+	ret float* %ret
+}
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture writeonly, i8* nocapture readonly, i64, i32, i1)
+
+!0 = !{}