Addressing review comments

Change-Id: I029312362f9dd714b2e9bc206cc002883d761b8b

Author: nasherm

llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp

@@ -56,7 +56,7 @@ static cl::opt<bool>
     AllowWLSLoops("allow-arm-wlsloops", cl::Hidden, cl::init(true),
                   cl::desc("Enable the generation of WLS loops"));
 
-static cl::opt<unsigned> UseWidenGlobalStrings(
+static cl::opt<bool> UseWidenGlobalArrays(
     "widen-global-strings", cl::Hidden, cl::init(true),
     cl::desc("Enable the widening of global strings to alignment boundaries"));
 
@@ -2815,6 +2815,11 @@ bool ARMTTIImpl::useWidenGlobalStrings() const { return UseWidenGlobalStrings; }
 
 unsigned ARMTTIImpl::getNumBytesToPadGlobalArray(unsigned Size,
                                                  Type *ArrayType) const {
+    if (!UseWidenGlobalArrays){
+        LLVM_DEBUG(dbgs() << "Padding global arrays disabled\n");
+        return false;
+    }
+
   // Don't modify none integer array types
   if (!ArrayType || !ArrayType->isArrayTy() ||
       !ArrayType->getArrayElementType()->isIntegerTy())

llvm/lib/Transforms/IPO/GlobalOpt.cpp

@@ -2043,13 +2043,9 @@ static bool callInstIsMemcpy(CallInst *CI) {
 }
 
 static bool destArrayCanBeWidened(CallInst *CI) {
-  auto *GV = dyn_cast<GlobalVariable>(CI->getArgOperand(0));
   auto *Alloca = dyn_cast<AllocaInst>(CI->getArgOperand(0));
   auto *IsVolatile = dyn_cast<ConstantInt>(CI->getArgOperand(3));
 
-  if (!GV || !GV->hasInitializer())
-    return false;
-
   if (!Alloca || !IsVolatile || IsVolatile->isOne())
     return false;
 
@@ -2129,12 +2125,17 @@ static bool tryWidenGlobalArrayAndDests(Function *F, GlobalVariable *SourceVar,
       widenGlobalVariable(SourceVar, F, NumBytesToPad, NumBytesToCopy);
   if (!NewSourceGV)
     return false;
+
   // Update arguments of remaining uses  that
   // are memcpys.
   for (auto *User : SourceVar->users()) {
     auto *CI = dyn_cast<CallInst>(User);
-    if (!callInstIsMemcpy(CI))
-      continue;
+      if (!callInstIsMemcpy(CI))
+          continue;
+
+    if (CI->getArgOperand(1) != SourceVar)
+        continue;
+
 
     widenDestArray(CI, NumBytesToPad, NumBytesToCopy, SourceDataArray);
 

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

@@ -1,9 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
-; RUN: opt -mtriple=arm-none-eabi -passes=globalopt -S | FileCheck %s
+; RUN: opt <%s -mtriple=arm-none-eabi -passes=globalopt -S | FileCheck %s
 
-; CHECK: [4 x i8]
 @.i8 = private unnamed_addr constant [3 x i8] [i8 1, i8 2, i8 3] , align 1
-; CHECK: [4 x i8]
 @other = private unnamed_addr global [3 x i8] [i8 1, i8 2, i8 3] , align 1
 
 define  void @memcpy_multiple()  {