diff --git a/clang/docs/ClangCommandLineReference.rst b/clang/docs/ClangCommandLineReference.rst
--- a/clang/docs/ClangCommandLineReference.rst
+++ b/clang/docs/ClangCommandLineReference.rst
@@ -2128,6 +2128,10 @@
 
 Enables splitting of the LTO unit
 
+.. option:: -fsplit-machine-functions, -fno-split-machine-functions
+
+Split machine functions using profile information (x86-elf only)
+
 .. option:: -fsplit-stack
 
 .. option:: -fstack-clash-protection
diff --git a/clang/include/clang/Basic/CodeGenOptions.def b/clang/include/clang/Basic/CodeGenOptions.def
--- a/clang/include/clang/Basic/CodeGenOptions.def
+++ b/clang/include/clang/Basic/CodeGenOptions.def
@@ -162,6 +162,7 @@
 CODEGENOPT(NullPointerIsValid , 1, 0) ///< Assume Null pointer deference is defined.
 CODEGENOPT(CorrectlyRoundedDivSqrt, 1, 0) ///< -cl-fp32-correctly-rounded-divide-sqrt
 CODEGENOPT(UniqueInternalLinkageNames, 1, 0) ///< Internal Linkage symbols get unique names.
+CODEGENOPT(SplitMachineFunctions, 1, 0) ///< Split machine functions using profile information.
 
 /// When false, this attempts to generate code as if the result of an
 /// overflowing conversion matches the overflowing behavior of a target's native
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1989,6 +1989,12 @@
 defm unique_section_names : OptOutFFlag<"unique-section-names",
   "", "Don't use unique names for text and data sections">;
 
+def fsplit_machine_functions : Flag <["-"], "fsplit-machine-functions">,
+  Group<f_Group>, Flags<[CC1Option]>,
+  HelpText<"Split machine functions using profile information (x86-elf only)">;
+def fno_split_machine_functions: Flag <["-"], "fno-split-machine-functions">,
+  Group<f_Group>;
+
 defm strict_return : OptOutFFlag<"strict-return", "",
   "Don't treat control flow paths that fall off the end of a non-void function as unreachable">;
 
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -9,6 +9,7 @@
 #include "clang/CodeGen/BackendUtil.h"
 #include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticFrontend.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Frontend/FrontendDiagnostic.h"
@@ -514,6 +515,15 @@
       Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
   }
 
+  if (CodeGenOpts.SplitMachineFunctions) {
+    if (CodeGenOpts.getProfileUse() != CodeGenOptions::ProfileNone)
+      Options.EnableMachineFunctionSplitter = true;
+    else
+      Diags.Report(diag::warn_fe_backend_optimization_failure)
+          << "ignored -fsplit-machine-functions, no profile provided via "
+             "-fprofile-use";
+  }
+
   Options.FunctionSections = CodeGenOpts.FunctionSections;
   Options.DataSections = CodeGenOpts.DataSections;
   Options.UniqueSectionNames = CodeGenOpts.UniqueSectionNames;
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4256,6 +4256,8 @@
         options::OPT_fno_unique_section_names,
         options::OPT_funique_basic_block_section_names,
         options::OPT_fno_unique_basic_block_section_names,
+        options::OPT_fsplit_machine_functions,
+        options::OPT_fno_split_machine_functions,
         options::OPT_mrestrict_it,
         options::OPT_mno_restrict_it,
         options::OPT_mstackrealign,
@@ -4911,6 +4913,15 @@
                    options::OPT_fno_unique_basic_block_section_names, false))
     CmdArgs.push_back("-funique-basic-block-section-names");
 
+  if (Args.hasFlag(options::OPT_fsplit_machine_functions,
+                   options::OPT_fno_split_machine_functions, false)) {
+    if (Triple.isX86() && Triple.isOSBinFormatELF())
+      CmdArgs.push_back("-fsplit-machine-functions");
+    else
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << "-fsplit-machine-functions" << TripleStr;
+  }
+
   Args.AddLastArg(CmdArgs, options::OPT_finstrument_functions,
                   options::OPT_finstrument_functions_after_inlining,
                   options::OPT_finstrument_function_entry_bare);
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -998,6 +998,8 @@
   Opts.UniqueInternalLinkageNames =
       Args.hasArg(OPT_funique_internal_linkage_names);
 
+  Opts.SplitMachineFunctions = Args.hasArg(OPT_fsplit_machine_functions);
+
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
 
   Opts.NoUseJumpTables = Args.hasArg(OPT_fno_jump_tables);
diff --git a/clang/test/CodeGen/split-machine-functions.c b/clang/test/CodeGen/split-machine-functions.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/split-machine-functions.c
@@ -0,0 +1,34 @@
+// REQUIRES: x86-registered-target
+
+// RUN: echo "foo"                > %t.proftext
+// RUN: echo "# Func Hash:"       >> %t.proftext
+// RUN: echo "11262309905"        >> %t.proftext
+// RUN: echo "# Num Counters:"    >> %t.proftext
+// RUN: echo "2"                  >> %t.proftext
+// RUN: echo "# Counter Values:"  >> %t.proftext
+// RUN: echo "1000000"            >> %t.proftext
+// RUN: echo "0"                  >> %t.proftext
+// RUN: llvm-profdata merge -o %t.profdata %t.proftext
+// RUN: %clang_cc1 -triple x86_64 -O3 -S -fprofile-instrument-use-path=%t.profdata -fsplit-machine-functions -o - < %s | FileCheck %s
+
+__attribute__((noinline)) int foo(int argc) {
+  if (argc % 2 == 0) {
+    exit(argc);
+  } else {
+    return argc + 1;
+  }
+}
+
+int main(int argc, char *argv[]) {
+  int total = 0;
+  for (int i = 0; i < 1000000; ++i) {
+    total += foo(argc);
+  }
+  printf("%d\n", total);
+}
+
+// CHECK: .section .text.hot.,"ax",@progbits
+// CHECK: foo:
+// CHECK: section .text.unlikely.foo,"ax",@progbits
+// CHECK: foo.cold:
+// CHECK: callq exit@PLT
diff --git a/clang/test/Driver/fsplit-machine-functions.c b/clang/test/Driver/fsplit-machine-functions.c
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/fsplit-machine-functions.c
@@ -0,0 +1,9 @@
+// RUN: %clang -### -target x86_64 -fsplit-machine-functions %s -c 2>&1 | FileCheck -check-prefix=CHECK-OPT %s
+// RUN: %clang -### -target x86_64 -fsplit-machine-functions -fno-split-machine-functions %s -c 2>&1 | FileCheck -check-prefix=CHECK-NOOPT %s
+// RUN: %clang -c -target x86_64 -fsplit-machine-functions %s -c 2>&1 | FileCheck -check-prefix=CHECK-WARN %s
+// RUN: not %clang -c -target arm-unknown-linux -fsplit-machine-functions %s -c 2>&1 | FileCheck -check-prefix=CHECK-TRIPLE %s
+
+// CHECK-OPT:       "-fsplit-machine-functions"
+// CHECK-NOOPT-NOT: "-fsplit-machine-functions"
+// CHECK-WARN:      ignored -fsplit-machine-functions, no profile provided via -fprofile-use
+// CHECK-TRIPLE:    error: unsupported option '-fsplit-machine-functions' for target