diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
index cb3dc17..c232aa6 100644
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -51,6 +51,7 @@
   SimplifyCFG.cpp
   SimplifyIndVar.cpp
   SimplifyLibCalls.cpp
+  SizeOpts.cpp
   SplitModule.cpp
   StripNonLineTableDebugInfo.cpp
   SymbolRewriter.cpp
diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index f35328ca..23b88db 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -16,8 +16,10 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Analysis/ValueTracking.h"
@@ -34,6 +36,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/KnownBits.h"
 #include "llvm/Transforms/Utils/BuildLibCalls.h"
+#include "llvm/Transforms/Utils/SizeOpts.h"
 
 using namespace llvm;
 using namespace PatternMatch;
@@ -2375,7 +2378,9 @@
 
   // Don't rewrite fputs to fwrite when optimising for size because fwrite
   // requires more arguments and thus extra MOVs are required.
-  if (CI->getFunction()->hasOptSize())
+  bool OptForSize = CI->getFunction()->hasOptSize() ||
+                    llvm::shouldOptimizeForSize(CI->getParent(), PSI, BFI);
+  if (OptForSize)
     return nullptr;
 
   // Check if has any use
@@ -2750,9 +2755,10 @@
 LibCallSimplifier::LibCallSimplifier(
     const DataLayout &DL, const TargetLibraryInfo *TLI,
     OptimizationRemarkEmitter &ORE,
+    BlockFrequencyInfo *BFI, ProfileSummaryInfo *PSI,
     function_ref<void(Instruction *, Value *)> Replacer,
     function_ref<void(Instruction *)> Eraser)
-    : FortifiedSimplifier(TLI), DL(DL), TLI(TLI), ORE(ORE),
+    : FortifiedSimplifier(TLI), DL(DL), TLI(TLI), ORE(ORE), BFI(BFI), PSI(PSI),
       UnsafeFPShrink(false), Replacer(Replacer), Eraser(Eraser) {}
 
 void LibCallSimplifier::replaceAllUsesWith(Instruction *I, Value *With) {
diff --git a/llvm/lib/Transforms/Utils/SizeOpts.cpp b/llvm/lib/Transforms/Utils/SizeOpts.cpp
new file mode 100644
index 0000000..1519751
--- /dev/null
+++ b/llvm/lib/Transforms/Utils/SizeOpts.cpp
@@ -0,0 +1,37 @@
+//===-- SizeOpts.cpp - code size optimization related code ----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains some shared code size optimization related code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/BlockFrequencyInfo.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Transforms/Utils/SizeOpts.h"
+using namespace llvm;
+
+static cl::opt<bool> ProfileGuidedSizeOpt(
+    "pgso", cl::Hidden, cl::init(true),
+    cl::desc("Enable the profile guided size optimization. "));
+
+bool llvm::shouldOptimizeForSize(Function *F, ProfileSummaryInfo *PSI,
+                                 BlockFrequencyInfo *BFI) {
+  assert(F);
+  if (!PSI || !BFI || !PSI->hasProfileSummary())
+    return false;
+  return ProfileGuidedSizeOpt && PSI->isFunctionColdInCallGraph(F, *BFI);
+}
+
+bool llvm::shouldOptimizeForSize(BasicBlock *BB, ProfileSummaryInfo *PSI,
+                                 BlockFrequencyInfo *BFI) {
+  assert(BB);
+  if (!PSI || !BFI || !PSI->hasProfileSummary())
+    return false;
+  return ProfileGuidedSizeOpt && PSI->isColdBlock(BB, BFI);
+}