From ac8be9e1f999ecf2cc298349420edc7f3f9c9fd6 Mon Sep 17 00:00:00 2001
From: Vedant Kumar <vsk@apple.com>
Date: Thu, 8 Nov 2018 14:08:35 -0800
Subject: [PATCH] Add a CC1 option to enable the Swift function-merging pass

Patch by Linus Nilsson.
---
 include/clang/Driver/CC1Options.td        | 2 ++
 include/clang/Frontend/CodeGenOptions.def | 1 +
 lib/CodeGen/BackendUtil.cpp               | 1 +
 lib/Driver/ToolChains/Clang.cpp           | 8 ++++++++
 lib/Frontend/CompilerInvocation.cpp       | 1 +
 test/CodeGenCXX/merge-functions.cpp       | 2 +-
 6 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index 67e7952742c..848d6dfc3dd 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -217,6 +217,8 @@ def fdump_vtable_layouts : Flag<["-"], "fdump-vtable-layouts">,
   HelpText<"Dump the layouts of all vtables that will be emitted in a translation unit">;
 def fmerge_functions : Flag<["-"], "fmerge-functions">,
   HelpText<"Permit merging of identical functions when optimizing.">;
+def fmerge_similar_functions : Flag<["-"], "fmerge-similar-functions">,
+  HelpText<"Permit merging of similar functions when optimizing.">;
 def femit_coverage_notes : Flag<["-"], "femit-coverage-notes">,
   HelpText<"Emit a gcov coverage notes file when compiling.">;
 def femit_coverage_data: Flag<["-"], "femit-coverage-data">,
diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index a7e71f7ac01..4be926c220c 100644
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -119,6 +119,7 @@ CODEGENOPT(IncrementalLinkerCompatible, 1, 0) ///< Emit an object file which can
                                               ///< linker.
 CODEGENOPT(MergeAllConstants , 1, 1) ///< Merge identical constants.
 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
+CODEGENOPT(MergeSimilarFunctions , 1, 0) ///< Set when -fmerge-similar-functions is enabled.
 CODEGENOPT(MSVolatile        , 1, 0) ///< Set when /volatile:ms is enabled.
 CODEGENOPT(NoCommon          , 1, 0) ///< Set when -fno-common or C++ is enabled.
 CODEGENOPT(NoDwarfDirectoryAsm , 1, 0) ///< Set when -fno-dwarf-directory-asm is
diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index 826ac267c68..5f50e265242 100644
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -535,6 +535,7 @@ void EmitAssemblyHelper::CreatePasses(legacy::PassManager &MPM,
 
   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
+  PMBuilder.MergeSimilarFunctions = CodeGenOpts.MergeSimilarFunctions;
   PMBuilder.PrepareForThinLTO = CodeGenOpts.PrepareForThinLTO;
   PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index 36375347b92..e6496094d4e 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -1,3 +1,5 @@
+
+
 //===--- LLVM.cpp - Clang+LLVM ToolChain Implementations --------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
@@ -3407,6 +3409,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                    options::OPT_fdelete_null_pointer_checks, false))
     CmdArgs.push_back("-fno-delete-null-pointer-checks");
 
+  if (Args.hasArg(options::OPT_fmerge_similar_functions))
+    CmdArgs.push_back("-fmerge-similar-functions");
+
+  if (Args.hasArg(options::OPT_fmerge_functions))
+    CmdArgs.push_back("-fmerge-functions");
+
   // LLVM Code Generator Options.
 
   if (Args.hasArg(options::OPT_frewrite_map_file) ||
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 588a30d503e..1012af62978 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -743,6 +743,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
                                          OPT_fno_unique_section_names, true);
 
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
+  Opts.MergeSimilarFunctions = Args.hasArg(OPT_fmerge_similar_functions);
 
   Opts.NoUseJumpTables = Args.hasArg(OPT_fno_jump_tables);
 
diff --git a/test/CodeGenCXX/merge-functions.cpp b/test/CodeGenCXX/merge-functions.cpp
index 2137f19c409..c3d0129f6c2 100644
--- a/test/CodeGenCXX/merge-functions.cpp
+++ b/test/CodeGenCXX/merge-functions.cpp
@@ -1,5 +1,5 @@
 // REQUIRES: x86-registered-target
-// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -O1 -fmerge-functions -emit-llvm -o - -x c++ < %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -O1 -fmerge-functions -fmerge-similar-functions -emit-llvm -o - -x c++ < %s | FileCheck %s
 
 // Basic functionality test. Function merging doesn't kick in on functions that
 // are too simple.