r239481 - Pass down the -flto option to the -cc1 job, and from there into the

[Teresa Johnson]

Author: tejohnson
Date: Wed Jun 10 12:49:45 2015
New Revision: 239481

URL: http://llvm.org/viewvc/llvm-project?rev=239481&view=rev
Log:
Pass down the -flto option to the -cc1 job, and from there into the
CodeGenOptions and onto the PassManagerBuilder. This enables gating
the new EliminateAvailableExternally module pass on whether we are
preparing for LTO.

If we are preparing for LTO (e.g. a -flto -c compile), the new pass is not
included as we want to preserve available externally functions for possible
link time inlining.

Modified:
    cfe/trunk/include/clang/Driver/Options.td
    cfe/trunk/include/clang/Frontend/CodeGenOptions.def
    cfe/trunk/lib/CodeGen/BackendUtil.cpp
    cfe/trunk/lib/Driver/Tools.cpp
    cfe/trunk/lib/Frontend/CompilerInvocation.cpp
    cfe/trunk/test/CodeGen/available-externally-suppress.c

Modified: cfe/trunk/include/clang/Driver/Options.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/include/clang/Driver/Options.td (original)
+++ cfe/trunk/include/clang/Driver/Options.td Wed Jun 10 12:49:45 2015
@@ -636,7 +636,7 @@ def flat__namespace : Flag<["-"], "flat_
 def flax_vector_conversions : Flag<["-"], "flax-vector-conversions">, Group<f_Group>;
 def flimited_precision_EQ : Joined<["-"], "flimited-precision=">, Group<f_Group>;
 def flto_EQ : Joined<["-"], "flto=">, Group<clang_ignored_gcc_optimization_f_Group>;
-def flto : Flag<["-"], "flto">, Group<f_Group>;
+def flto : Flag<["-"], "flto">, Flags<[CC1Option]>, Group<f_Group>;
 def fno_lto : Flag<["-"], "fno-lto">, Group<f_Group>;
 def fmacro_backtrace_limit_EQ : Joined<["-"], "fmacro-backtrace-limit=">,
                                 Group<f_Group>, Flags<[DriverOption, CoreOption]>;

Modified: cfe/trunk/include/clang/Frontend/CodeGenOptions.def
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Frontend/CodeGenOptions.def?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/include/clang/Frontend/CodeGenOptions.def (original)
+++ cfe/trunk/include/clang/Frontend/CodeGenOptions.def Wed Jun 10 12:49:45 2015
@@ -67,6 +67,8 @@ CODEGENOPT(InstrumentFunctions , 1, 0) /
 CODEGENOPT(InstrumentForProfiling , 1, 0) ///< Set when -pg is enabled.
 CODEGENOPT(LessPreciseFPMAD  , 1, 0) ///< Enable less precise MAD instructions to
                                      ///< be generated.
+CODEGENOPT(PrepareForLTO     , 1, 0) ///< Set when -flto is enabled on the
+                                     ///< compile step.
 CODEGENOPT(MergeAllConstants , 1, 1) ///< Merge identical constants.
 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
 CODEGENOPT(MSVolatile        , 1, 0) ///< Set when /volatile:ms is enabled.

Modified: cfe/trunk/lib/CodeGen/BackendUtil.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/BackendUtil.cpp?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/BackendUtil.cpp (original)
+++ cfe/trunk/lib/CodeGen/BackendUtil.cpp Wed Jun 10 12:49:45 2015
@@ -286,6 +286,7 @@ void EmitAssemblyHelper::CreatePasses()
   PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
   PMBuilder.MergeFunctions = CodeGenOpts.MergeFunctions;
+  PMBuilder.PrepareForLTO = CodeGenOpts.PrepareForLTO;
   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;
 
   PMBuilder.addExtension(PassManagerBuilder::EP_EarlyAsPossible,

Modified: cfe/trunk/lib/Driver/Tools.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Tools.cpp (original)
+++ cfe/trunk/lib/Driver/Tools.cpp Wed Jun 10 12:49:45 2015
@@ -2703,6 +2703,10 @@ void Clang::ConstructJob(Compilation &C,
     assert((isa<CompileJobAction>(JA) || isa<BackendJobAction>(JA)) &&
            "Invalid action for clang tool.");
 
+    if (JA.getType() == types::TY_LTO_IR ||
+        JA.getType() == types::TY_LTO_BC) {
+      CmdArgs.push_back("-flto");
+    }
     if (JA.getType() == types::TY_Nothing) {
       CmdArgs.push_back("-fsyntax-only");
     } else if (JA.getType() == types::TY_LLVM_IR ||

Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original)
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Wed Jun 10 12:49:45 2015
@@ -485,6 +485,8 @@ static bool ParseCodeGenArgs(CodeGenOpti
 
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
 
+  Opts.PrepareForLTO = Args.hasArg(OPT_flto);
+
   Opts.MSVolatile = Args.hasArg(OPT_fms_volatile);
 
   Opts.VectorizeBB = Args.hasArg(OPT_vectorize_slp_aggressive);

Modified: cfe/trunk/test/CodeGen/available-externally-suppress.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/available-externally-suppress.c?rev=239481&r1=239480&r2=239481&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/available-externally-suppress.c (original)
+++ cfe/trunk/test/CodeGen/available-externally-suppress.c Wed Jun 10 12:49:45 2015
@@ -1,12 +1,18 @@
 // RUN: %clang_cc1 -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s
+// RUN: %clang_cc1 -O2 -fno-inline -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s
+// RUN: %clang_cc1 -flto -O2 -fno-inline -emit-llvm -o - -triple x86_64-apple-darwin10 %s | FileCheck %s -check-prefix=LTO
 
 // Ensure that we don't emit available_externally functions at -O0.
+// Also should not emit them at -O2, unless -flto is present in which case
+// we should preserve them for link-time inlining decisions.
 int x;
 
 inline void f0(int y) { x = y; }
 
 // CHECK-LABEL: define void @test()
 // CHECK: declare void @f0(i32)
+// LTO-LABEL: define void @test()
+// LTO: define available_externally void @f0
 void test() {
   f0(17);
 }
@@ -19,9 +25,13 @@ inline int __attribute__((always_inline)
 }
 
 // CHECK: @test1
+// LTO: @test1
 int test1(int x) {
   // CHECK: br i1
   // CHECK-NOT: call {{.*}} @f1
   // CHECK: ret i32
+  // LTO: br i1
+  // LTO-NOT: call {{.*}} @f1
+  // LTO: ret i32
   return f1(x);
 }