Index: lib/Transforms/Utils/SimplifyLibCalls.cpp
===================================================================
--- lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -538,7 +538,7 @@
 }
 
 Value *LibCallSimplifier::optimizeWcslen(CallInst *CI, IRBuilder<> &B) {
-  Module &M = *CI->getParent()->getParent()->getParent();
+  Module &M = *CI->getModule();
   unsigned WCharSize = TLI->getWCharSize(M) * 8;
   // We cannot perform this optimization without wchar_size metadata.
   if (WCharSize == 0)
@@ -1865,9 +1865,8 @@
   if (CI->getNumArgOperands() == 2) {
     // Make sure there's no % in the constant array.  We could try to handle
     // %% -> % in the future if we cared.
-    for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
-      if (FormatStr[i] == '%')
-        return nullptr; // we found a format specifier, bail out.
+    if (FormatStr.find('%') != StringRef::npos)
+      return nullptr; // we found a format specifier, bail out.
 
     // sprintf(str, fmt) -> llvm.memcpy(align 1 str, align 1 fmt, strlen(fmt)+1)
     B.CreateMemCpy(CI->getArgOperand(0), 1, CI->getArgOperand(1), 1,
@@ -1952,9 +1951,8 @@
   if (CI->getNumArgOperands() == 3) {
     // Make sure there's no % in the constant array.  We could try to handle
     // %% -> % in the future if we cared.
-    for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
-      if (FormatStr[i] == '%')
-        return nullptr; // we found a format specifier, bail out.
+    if (FormatStr.find('%') != StringRef::npos)
+      return nullptr; // we found a format specifier, bail out.
 
     if (N == 0)
       return ConstantInt::get(CI->getType(), FormatStr.size());
@@ -2039,9 +2037,9 @@
 
   // fprintf(F, "foo") --> fwrite("foo", 3, 1, F)
   if (CI->getNumArgOperands() == 2) {
-    for (unsigned i = 0, e = FormatStr.size(); i != e; ++i)
-      if (FormatStr[i] == '%') // Could handle %% -> % if we cared.
-        return nullptr;        // We found a format specifier.
+    // Could handle %% -> % if we cared.
+    if (FormatStr.find('%') != StringRef::npos)
+      return nullptr; // We found a format specifier.
 
     return emitFWrite(
         CI->getArgOperand(1),
@@ -2128,7 +2126,7 @@
 
   // Don't rewrite fputs to fwrite when optimising for size because fwrite
   // requires more arguments and thus extra MOVs are required.
-  if (CI->getParent()->getParent()->optForSize())
+  if (CI->getFunction()->optForSize())
     return nullptr;
 
   // Check if has any use