Responding to review comments

- Added test showing behaviour of attempting to
  widen non-const globals
- Refactoring

Change-Id: I566214331bf3d889bd1409d3148aa6eab2530ed5

Author: nasherm

llvm/lib/Transforms/IPO/GlobalOpt.cpp

@@ -2113,10 +2113,6 @@ static bool tryWidenGlobalArrayAndDests(Function *F, GlobalVariable *SourceVar,
                                         const unsigned NumBytesToCopy,
                                         ConstantInt *BytesToCopyOp,
                                         ConstantDataArray *SourceDataArray) {
-  if (!SourceVar->hasInitializer() || !SourceVar->isConstant() ||
-      !SourceVar->hasLocalLinkage() || !SourceVar->hasGlobalUnnamedAddr())
-    return false;
-
   auto *NewSourceGV =
       widenGlobalVariable(SourceVar, F, NumBytesToPad, NumBytesToCopy);
   if (!NewSourceGV)
@@ -2147,7 +2143,8 @@ static bool tryWidenGlobalArraysUsedByMemcpy(
     GlobalVariable *GV,
     function_ref<TargetTransformInfo &(Function &)> GetTTI) {
 
-  if (!GV->hasInitializer())
+  if (!GV->hasInitializer() || !GV->isConstant() || !GV->hasLocalLinkage() ||
+      !GV->hasGlobalUnnamedAddr())
     return false;
 
   for (auto *User : GV->users()) {

llvm/test/Transforms/GlobalOpt/ARM/arm-widen-non-const-global.ll

@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -mtriple=arm-none-eabi -passes=globalopt -S | FileCheck %s
+
+@.str = unnamed_addr global [3 x i8] c"12\00", align 1
+
+define  void @foo()  {
+; CHECK-LABEL: define void @foo() local_unnamed_addr {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    [[SOMETHING:%.*]] = alloca [3 x i8], align 1
+; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(3) [[SOMETHING]], ptr noundef nonnull align 1 dereferenceable(3) @.str, i32 3, i1 false)
+; CHECK-NEXT:    [[CALL1:%.*]] = call i32 @bar(ptr nonnull [[SOMETHING]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %something = alloca [3 x i8], align 1
+  call void @llvm.memcpy.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(3) %something, ptr noundef nonnull align 1 dereferenceable(3) @.str, i32 3, i1 false)
+  %call1 = call i32 @bar(ptr nonnull %something)
+  ret void
+}
+
+declare i32 @bar(...)