diff --git a/llvm/include/llvm/Transforms/Utils/FunctionAnnotator.h b/llvm/include/llvm/Transforms/Utils/FunctionAnnotator.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/Transforms/Utils/FunctionAnnotator.h
@@ -0,0 +1,26 @@
+//===-- FunctionAnnotator.h - FunctionAnnotator ---------------*- C++ -*-===//
+//
+// 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 defines the FunctionAnnotator class which is used in phase
+// ordering.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_FUNCTIONANNOTATOR_H
+#define LLVM_TRANSFORMS_FUNCTIONANNOTATOR_H
+
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/CommandLine.h"
+
+namespace llvm {
+class FunctionAnnotator : public PassInfoMixin<FunctionAnnotator> {
+public:
+  PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+};
+
+} // namespace llvm
+
+#endif // LLVM_TRANSFORMS_FUNCTIONANNOTATOR_H
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -232,6 +232,7 @@
 #include "llvm/Transforms/Utils/Debugify.h"
 #include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
 #include "llvm/Transforms/Utils/FixIrreducible.h"
+#include "llvm/Transforms/Utils/FunctionAnnotator.h"
 #include "llvm/Transforms/Utils/HelloWorld.h"
 #include "llvm/Transforms/Utils/InjectTLIMappings.h"
 #include "llvm/Transforms/Utils/InstructionNamer.h"
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -59,6 +59,7 @@
 MODULE_PASS("elim-avail-extern", EliminateAvailableExternallyPass())
 MODULE_PASS("extract-blocks", BlockExtractorPass({}, false))
 MODULE_PASS("forceattrs", ForceFunctionAttrsPass())
+MODULE_PASS("function-annotator", FunctionAnnotator())
 MODULE_PASS("function-import", FunctionImportPass())
 MODULE_PASS("globaldce", GlobalDCEPass())
 MODULE_PASS("globalopt", GlobalOptPass())
diff --git a/llvm/lib/Transforms/Utils/CMakeLists.txt b/llvm/lib/Transforms/Utils/CMakeLists.txt
--- a/llvm/lib/Transforms/Utils/CMakeLists.txt
+++ b/llvm/lib/Transforms/Utils/CMakeLists.txt
@@ -25,6 +25,7 @@
   Evaluator.cpp
   FixIrreducible.cpp
   FlattenCFG.cpp
+  FunctionAnnotator.cpp
   FunctionComparator.cpp
   FunctionImportUtils.cpp
   GlobalStatus.cpp
diff --git a/llvm/lib/Transforms/Utils/FunctionAnnotator.cpp b/llvm/lib/Transforms/Utils/FunctionAnnotator.cpp
new file mode 100644
--- /dev/null
+++ b/llvm/lib/Transforms/Utils/FunctionAnnotator.cpp
@@ -0,0 +1,59 @@
+//===- FunctionAnnotator.cpp - Function Annotator -------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Annotates functions with the appropriate optimization level attribute for
+// assistance in phase ordering.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/FunctionAnnotator.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/LineIterator.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Testing/Annotations/Annotations.h"
+
+using namespace llvm;
+
+static cl::opt<std::string>
+    OptLevelAttributeName("opt-level-attribute-name", cl::init("opt-level"),
+                          cl::Hidden, cl::desc("Optimization attribute name"));
+
+static cl::opt<std::string> CSVFilePath(
+    "func-annotator-csv-file-path", cl::Hidden,
+    cl::desc("CSV file containing function names and optimization level as "
+             "attribute"));
+
+PreservedAnalyses FunctionAnnotator::run(Module &M, ModuleAnalysisManager &AM) {
+
+  auto BufferOrError = MemoryBuffer::getFileOrSTDIN(CSVFilePath);
+  if (!BufferOrError) {
+    report_fatal_error("Cannot open CSV File");
+  }
+
+  StringRef Buffer = BufferOrError.get()->getBuffer();
+  auto MemoryBuffer = MemoryBuffer::getMemBuffer(Buffer);
+  line_iterator It(*MemoryBuffer);
+  for (++It; !It.is_at_end(); ++It) {
+    auto SplitPair = It->split(',');
+    if (!SplitPair.second.empty()) {
+      Function *Func = M.getFunction(SplitPair.first);
+      if (Func) {
+        if (Func->isDeclaration()) {
+          continue;
+        }
+        Func->addFnAttr(OptLevelAttributeName, SplitPair.second);
+      } else {
+        errs() << "Function in CSV file at line " << It.line_number()
+               << " does not exist\n";
+        continue;
+      }
+    }
+  }
+
+  return PreservedAnalyses::all();
+}
diff --git a/llvm/test/Transforms/Annotations/FunctionAnnotation.csv b/llvm/test/Transforms/Annotations/FunctionAnnotation.csv
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Annotations/FunctionAnnotation.csv
@@ -0,0 +1,6 @@
+FunctionName,OptimizationLevel
+first_function,O1
+second_function,O3
+third_function,O1
+fourth_function,O2
+fifth_function,O3
diff --git a/llvm/test/Transforms/Annotations/FunctionAnnotator.ll b/llvm/test/Transforms/Annotations/FunctionAnnotator.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/Annotations/FunctionAnnotator.ll
@@ -0,0 +1,34 @@
+; RUN: opt -passes='function-annotator' -func-annotator-csv-file-path="%S/FunctionAnnotation.csv" -opt-level-attribute-name="opt-level" -S < %s | FileCheck %s
+define void @first_function() #0 {
+; CHECK: first_function
+  ret void
+}
+
+define void @second_function() #1 {
+; CHECK: second_function 
+  ret void
+}
+
+define void @third_function() #0 {
+; CHECK: third_function
+  ret void
+}
+
+define void @fourth_function() #2 {
+; CHECK: fourth_function
+  ret void
+}
+
+define void @fifth_function() #1 {
+; CHECK: fifth_function
+  ret void
+}
+
+; CHECK-LABEL: attributes #0
+attributes #0 = { "opt-level"="O1" }
+
+; CHECK-LABEL: attributes #1
+attributes #1 = { "opt-level"="O3" }
+
+; CHECK-LABEL: attributes #2
+attributes #2 = { "opt-level"="O2" }