Index: llvm/lib/Transforms/IPO/GlobalOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -665,6 +665,9 @@
       }
     } else if (const BitCastInst *CI = dyn_cast<BitCastInst>(U)) {
       if (!AllUsesOfValueWillTrapIfNull(CI, PHIs)) return false;
+    } else if (const AddrSpaceCastInst *CI = dyn_cast<AddrSpaceCastInst>(U)) {
+      if (!AllUsesOfValueWillTrapIfNull(CI, PHIs))
+        return false;
     } else if (const GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(U)) {
       if (!AllUsesOfValueWillTrapIfNull(GEPI, PHIs)) return false;
     } else if (const PHINode *PN = dyn_cast<PHINode>(U)) {
@@ -845,7 +848,8 @@
       assert((isa<PHINode>(GlobalUser) || isa<SelectInst>(GlobalUser) ||
               isa<ConstantExpr>(GlobalUser) || isa<CmpInst>(GlobalUser) ||
               isa<BitCastInst>(GlobalUser) ||
-              isa<GetElementPtrInst>(GlobalUser)) &&
+              isa<GetElementPtrInst>(GlobalUser) ||
+              isa<AddrSpaceCastInst>(GlobalUser)) &&
              "Only expect load and stores!");
     }
   }
Index: llvm/test/Transforms/GlobalOpt/load-store-global.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/load-store-global.ll
+++ llvm/test/Transforms/GlobalOpt/load-store-global.ll
@@ -35,3 +35,14 @@
 ; CHECK-NOT: load
 }
 
+@addrspacecast_a = internal global ptr null
+
+define void @addrspacecast_user() {
+; CHECK-LABEL: @addrspacecast_user
+; CHECK-NOT: store
+; CHECK-NOT: load
+  %g = addrspacecast ptr @addrspacecast_a to ptr addrspace(1)
+  store ptr inttoptr (i64 1 to ptr), ptr @addrspacecast_a, align 8
+  %l = load ptr, ptr @addrspacecast_a, align 8
+  ret void
+}
Index: llvm/test/Transforms/GlobalOpt/malloc-promote-addrspacecast.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/malloc-promote-addrspacecast.ll
+++ llvm/test/Transforms/GlobalOpt/malloc-promote-addrspacecast.ll
@@ -6,16 +6,8 @@
 
 @G = internal global ptr null
 
-;.
-; CHECK: @[[G:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global ptr null
-;.
 define void @init() {
 ; CHECK-LABEL: @init(
-; CHECK-NEXT:    [[MALLOCCALL:%.*]] = tail call ptr @malloc(i64 4)
-; CHECK-NEXT:    store ptr [[MALLOCCALL]], ptr @G, align 8
-; CHECK-NEXT:    [[GV:%.*]] = load ptr, ptr @G, align 8
-; CHECK-NEXT:    [[ADDRSPACECAST:%.*]] = addrspacecast ptr [[GV]] to ptr addrspace(1)
-; CHECK-NEXT:    store i32 20, ptr addrspace(1) [[ADDRSPACECAST]], align 4
 ; CHECK-NEXT:    ret void
 ;
   %malloccall = tail call ptr @malloc(i64 4)
@@ -28,9 +20,7 @@
 
 define i32 @get() {
 ; CHECK-LABEL: @get(
-; CHECK-NEXT:    [[GV:%.*]] = load ptr, ptr @G, align 8
-; CHECK-NEXT:    [[V:%.*]] = load i32, ptr [[GV]], align 4
-; CHECK-NEXT:    ret i32 [[V]]
+; CHECK-NEXT:    ret i32 20
 ;
   %GV = load ptr, ptr @G
   %V = load i32, ptr %GV
@@ -40,7 +30,6 @@
 define void @foo(i64 %Size) nounwind noinline #0 {
 ; CHECK-LABEL: @foo(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = load ptr, ptr @G, align 4
 ; CHECK-NEXT:    ret void
 ;
 entry:
@@ -51,6 +40,5 @@
 attributes #0 = { null_pointer_is_valid }
 
 ;.
-; CHECK: attributes #[[ATTR0:[0-9]+]] = { allockind("alloc,uninitialized") allocsize(0) }
-; CHECK: attributes #[[ATTR1:[0-9]+]] = { noinline nounwind null_pointer_is_valid }
+; CHECK: attributes #[[ATTR0:[0-9]+]] = { noinline nounwind null_pointer_is_valid }
 ;.