Index: llvm/lib/Transforms/IPO/GlobalOpt.cpp
===================================================================
--- llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -338,6 +338,7 @@
 
 struct GlobalPart {
   Type *Ty;
+  bool IsLoaded = false;
 };
 
 /// Look at all uses of the global and determine which (offset, type) pairs it
@@ -381,6 +382,7 @@
       auto It = Parts.try_emplace(Offset.getZExtValue(), GlobalPart{Ty}).first;
       if (Ty != It->second.Ty)
         return false;
+      It->second.IsLoaded |= isa<LoadInst>(V);
       continue;
     }
 
@@ -467,8 +469,12 @@
   if (Parts.size() == 1 && Parts.begin()->second.Ty == GV->getValueType())
     return nullptr;
 
-  // Don't perform SRA if we would have to split into many globals.
-  if (Parts.size() > 16)
+  // Don't perform SRA if we would have to split into many globals. Ignore
+  // parts that are never loaded, because we expect them to be optimized away.
+  unsigned NumParts = count_if(Parts, [](const auto &Pair) {
+    return Pair.second.IsLoaded;
+  });
+  if (NumParts > 16)
     return nullptr;
 
   // Sort by offset.
Index: llvm/test/Transforms/GlobalOpt/sra-many-stores.ll
===================================================================
--- llvm/test/Transforms/GlobalOpt/sra-many-stores.ll
+++ llvm/test/Transforms/GlobalOpt/sra-many-stores.ll
@@ -6,14 +6,8 @@
 @global = internal global %struct.widget zeroinitializer
 
 
-;.
-; CHECK: @[[GLOBAL:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global [[STRUCT_WIDGET:%.*]] zeroinitializer
-; CHECK: @[[GLOBAL_ARRAY_IN_STRUCT:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global [[STRUCT_WITH_ARRAY:%.*]] zeroinitializer
-; CHECK: @[[GLOBAL_ARRAY:[a-zA-Z0-9_$"\\.-]+]] = internal unnamed_addr global [100 x i64] zeroinitializer
-;.
 define internal void @read_struct() {
 ; CHECK-LABEL: @read_struct(
-; CHECK-NEXT:    [[TMP:%.*]] = load ptr, ptr getelementptr inbounds ([[STRUCT_WIDGET:%.*]], ptr @global, i64 0, i32 16), align 8
 ; CHECK-NEXT:    ret void
 ;
   %tmp = load ptr, ptr getelementptr inbounds (%struct.widget, ptr @global, i64 0, i32 16), align 8
@@ -22,22 +16,6 @@
 
 define void @write_struct() {
 ; CHECK-LABEL: @write_struct(
-; CHECK-NEXT:    store ptr null, ptr @global, align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET:%.*]], ptr @global, i64 0, i32 1), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 2), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 3), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 4), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 5), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 6), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 7), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 8), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 9), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 10), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 11), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 12), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 13), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 14), align 8
-; CHECK-NEXT:    store ptr null, ptr getelementptr inbounds ([[STRUCT_WIDGET]], ptr @global, i64 0, i32 15), align 8
 ; CHECK-NEXT:    tail call fastcc void @read_struct()
 ; CHECK-NEXT:    ret void
 ;
@@ -68,7 +46,6 @@
 
 define internal void @read_non_array_field() {
 ; CHECK-LABEL: @read_non_array_field(
-; CHECK-NEXT:    [[TMP:%.*]] = load i64, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY:%.*]], ptr @global.array_in_struct, i64 0, i32 1), align 8
 ; CHECK-NEXT:    ret void
 ;
   %tmp = load i64, ptr getelementptr inbounds (%struct.with.array, ptr @global.array_in_struct, i64 0, i32 1), align 8
@@ -77,22 +54,6 @@
 
 define void @store_to_struct_array() {
 ; CHECK-LABEL: @store_to_struct_array(
-; CHECK-NEXT:    store i64 0, ptr @global.array_in_struct, align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY:%.*]], ptr @global.array_in_struct, i64 0, i32 0, i32 1), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 2), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 3), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 4), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 5), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 6), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 7), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 8), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 9), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 10), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 11), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 12), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 13), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 14), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([[STRUCT_WITH_ARRAY]], ptr @global.array_in_struct, i64 0, i32 0, i32 15), align 8
 ; CHECK-NEXT:    tail call fastcc void @read_non_array_field()
 ; CHECK-NEXT:    ret void
 ;
@@ -120,7 +81,6 @@
 
 define internal void @read_array() {
 ; CHECK-LABEL: @read_array(
-; CHECK-NEXT:    [[TMP:%.*]] = load i64, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 99), align 8
 ; CHECK-NEXT:    ret void
 ;
   %tmp = load i64, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 99), align 8
@@ -129,22 +89,6 @@
 
 define void @store_to_array() {
 ; CHECK-LABEL: @store_to_array(
-; CHECK-NEXT:    store i64 0, ptr @global.array, align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 1), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 2), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 3), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 4), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 5), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 6), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 7), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 8), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 9), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 10), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 11), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 12), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 13), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 14), align 8
-; CHECK-NEXT:    store i64 0, ptr getelementptr inbounds ([100 x i64], ptr @global.array, i64 0, i32 15), align 8
 ; CHECK-NEXT:    tail call fastcc void @read_array()
 ; CHECK-NEXT:    ret void
 ;