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
@@ -212,6 +212,10 @@
 ENUM_CODEGENOPT(ProfileInstr, ProfileInstrKind, 2, ProfileNone)
 /// Choose profile kind for PGO use compilation.
 ENUM_CODEGENOPT(ProfileUse, ProfileInstrKind, 2, ProfileNone)
+/// Partition functions into N groups and select only functions in group i to be
+/// instrumented. Selected group numbers can be 0 to N-1 inclusive.
+VALUE_CODEGENOPT(ProfileTotalFunctionGroups, 32, 1)
+VALUE_CODEGENOPT(ProfileSelectedFunctionGroup, 32, 0)
 CODEGENOPT(CoverageMapping , 1, 0) ///< Generate coverage mapping regions to
                                    ///< enable code coverage analysis.
 CODEGENOPT(DumpCoverageMapping , 1, 0) ///< Dump the generated coverage mapping
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
@@ -1333,6 +1333,15 @@
     Group<f_Group>, Flags<[CC1Option, CoreOption]>,
     HelpText<"Filename defining the list of functions/files to instrument">,
     MarshallingInfoStringVector<LangOpts<"ProfileListFiles">>;
+def fprofile_function_groups : Joined<["-"], "fprofile-function-groups=">,
+  Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<N>">,
+  HelpText<"Partition functions into N groups and select only functions in group i to be instrumented using -fprofile-selected-function-group">,
+  MarshallingInfoInt<CodeGenOpts<"ProfileTotalFunctionGroups">, "1">;
+def fprofile_selected_function_group :
+  Joined<["-"], "fprofile-selected-function-group=">, Group<f_Group>,
+  Flags<[CC1Option]>, MetaVarName<"<i>">,
+  HelpText<"Partition functions into N groups using -fprofile-function-groups and select only functions in group i to be instrumented. The valid range is 0 to N-1 inclusive">,
+  MarshallingInfoInt<CodeGenOpts<"ProfileSelectedFunctionGroup">>;
 def fswift_async_fp_EQ : Joined<["-"], "fswift-async-fp=">,
     Group<f_Group>, Flags<[CC1Option, CC1AsOption, CoreOption]>, MetaVarName<"<option>">,
     HelpText<"Control emission of Swift async extended frame info">,
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -852,7 +852,7 @@
   }
 
   if (CGM.getCodeGenOpts().getProfileInstr() != CodeGenOptions::ProfileNone)
-    if (CGM.isProfileInstrExcluded(Fn, Loc))
+    if (CGM.isFunctionBlockedFromProfileInstr(Fn, Loc))
       Fn->addFnAttr(llvm::Attribute::NoProfile);
 
   unsigned Count, Offset;
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1326,9 +1326,15 @@
   bool imbueXRayAttrs(llvm::Function *Fn, SourceLocation Loc,
                       StringRef Category = StringRef()) const;
 
-  /// Returns true if function at the given location should be excluded from
-  /// profile instrumentation.
-  bool isProfileInstrExcluded(llvm::Function *Fn, SourceLocation Loc) const;
+  /// \returns true if \p Fn at \p Loc should be excluded from profile
+  /// instrumentation by the SCL passed by \p -fprofile-list.
+  bool isFunctionBlockedByProfileList(llvm::Function *Fn,
+                                      SourceLocation Loc) const;
+
+  /// \returns true if \p Fn at \p Loc should be excluded from profile
+  /// instrumentation.
+  bool isFunctionBlockedFromProfileInstr(llvm::Function *Fn,
+                                         SourceLocation Loc) const;
 
   SanitizerMetadata *getSanitizerMetadata() {
     return SanitizerMD.get();
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2833,8 +2833,8 @@
   return true;
 }
 
-bool CodeGenModule::isProfileInstrExcluded(llvm::Function *Fn,
-                                           SourceLocation Loc) const {
+bool CodeGenModule::isFunctionBlockedByProfileList(llvm::Function *Fn,
+                                                   SourceLocation Loc) const {
   const auto &ProfileList = getContext().getProfileList();
   // If the profile list is empty, then instrument everything.
   if (ProfileList.isEmpty())
@@ -2861,6 +2861,20 @@
   return ProfileList.getDefault();
 }
 
+bool CodeGenModule::isFunctionBlockedFromProfileInstr(
+    llvm::Function *Fn, SourceLocation Loc) const {
+  if (isFunctionBlockedByProfileList(Fn, Loc))
+    return true;
+
+  auto NumGroups = getCodeGenOpts().ProfileTotalFunctionGroups;
+  if (NumGroups > 1) {
+    auto Group = llvm::MD5Hash(Fn->getName()) % NumGroups;
+    if (Group != getCodeGenOpts().ProfileSelectedFunctionGroup)
+      return true;
+  }
+  return false;
+}
+
 bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
   // Never defer when EmitAllDecls is specified.
   if (LangOpts.EmitAllDecls)
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
@@ -982,6 +982,27 @@
     CmdArgs.push_back("-fprofile-update=atomic");
   }
 
+  int FunctionGroups = 1;
+  int SelectedFunctionGroup = 0;
+  if (const auto *A = Args.getLastArg(options::OPT_fprofile_function_groups)) {
+    StringRef Val = A->getValue();
+    if (Val.getAsInteger(0, FunctionGroups) || FunctionGroups < 1)
+      D.Diag(diag::err_drv_invalid_int_value) << A->getAsString(Args) << Val;
+  }
+  if (const auto *A =
+          Args.getLastArg(options::OPT_fprofile_selected_function_group)) {
+    StringRef Val = A->getValue();
+    if (Val.getAsInteger(0, SelectedFunctionGroup) ||
+        SelectedFunctionGroup < 0 || SelectedFunctionGroup >= FunctionGroups)
+      D.Diag(diag::err_drv_invalid_int_value) << A->getAsString(Args) << Val;
+  }
+  if (FunctionGroups != 1)
+    CmdArgs.push_back(Args.MakeArgString("-fprofile-function-groups=" +
+                                         Twine(FunctionGroups)));
+  if (SelectedFunctionGroup != 0)
+    CmdArgs.push_back(Args.MakeArgString("-fprofile-selected-function-group=" +
+                                         Twine(SelectedFunctionGroup)));
+
   // Leave -fprofile-dir= an unused argument unless .gcda emission is
   // enabled. To be polite, with '-fprofile-arcs -fno-profile-arcs' consider
   // the flag used. There is no -fno-profile-dir, so the user has no
diff --git a/clang/test/CodeGen/profile-function-groups.c b/clang/test/CodeGen/profile-function-groups.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/profile-function-groups.c
@@ -0,0 +1,24 @@
+// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=0 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT0
+// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=1 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT1
+// RUN: %clang -fprofile-generate -fprofile-function-groups=3 -fprofile-selected-function-group=2 -emit-llvm -S %s -o - | FileCheck %s --check-prefixes=CHECK,SELECT2
+
+// Group 0
+// SELECT0-NOT: noprofile
+// SELECT1: noprofile
+// SELECT2: noprofile
+// CHECK-LABEL: define {{.*}} void @goo()
+void goo() {}
+
+// Group 1
+// SELECT0: noprofile
+// SELECT1-NOT: noprofile
+// SELECT2: noprofile
+// CHECK-LABEL: define {{.*}} void @boo()
+void boo() {}
+
+// Group 2
+// SELECT0: noprofile
+// SELECT1: noprofile
+// SELECT2-NOT: noprofile
+// CHECK-LABEL: define {{.*}} void @foo()
+void foo() {}
diff --git a/compiler-rt/test/profile/instrprof-groups.c b/compiler-rt/test/profile/instrprof-groups.c
new file mode 100644
--- /dev/null
+++ b/compiler-rt/test/profile/instrprof-groups.c
@@ -0,0 +1,28 @@
+// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=0 %s -o %t.0.out
+// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=1 %s -o %t.1.out
+// RUN: %clang_pgogen -fprofile-function-groups=3 -fprofile-selected-function-group=2 %s -o %t.2.out
+// RUN: env LLVM_PROFILE_FILE=%t.0.profraw %run %t.0.out
+// RUN: env LLVM_PROFILE_FILE=%t.1.profraw %run %t.1.out
+// RUN: env LLVM_PROFILE_FILE=%t.2.profraw %run %t.2.out
+// RUN: llvm-profdata merge -o %t.profdata %t.*.profraw
+// RUN: llvm-profdata show %t.profdata --all-functions | FileCheck %s
+
+int foo(int i) { return 4 * i + 1; }
+int bar(int i) { return 4 * i + 2; }
+int goo(int i) { return 4 * i + 3; }
+
+int main(int argc, char *argv[]) {
+  foo(5);
+  bar(6);
+  goo(7);
+  return 0;
+}
+
+// Even though we ran this code three times, we expect all counts to be one if
+// functions were partitioned into groups correctly.
+
+// CHECK: Counters: 1
+// CHECK: Counters: 1
+// CHECK: Counters: 1
+// CHECK: Counters: 1
+// CHECK: Total functions: 4