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.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@239481 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 7e39a9ae5b22e50f8f38864239842b5f10e62627..d808c1913ee7c512496086e7153f20dd416ffc8f 100644 (file)
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -636,7 +636,7 @@ def flat__namespace : Flag<["-"], "flat_namespace">;
 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]>;

diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index adf1c879d40e89bc9ce061a2c1366e0d21745345..3ab99c2c2989c2615ec2a8ac4d34ca4e7d0b961e 100644 (file)
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -67,6 +67,8 @@ CODEGENOPT(InstrumentFunctions , 1, 0) ///< Set when -finstrument-functions is
 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.

diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index 671518170aa7c5ba1456550e71afe5f6f2be4482..cb077e6486328297ddf85611565410884ad1a4e7 100644 (file)
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -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,

diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 711dee273197ed367a8dde38bed8f5115106c84b..454f1d85857b9f8cabd95021d67b95b01cb1b818 100644 (file)
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2703,6 +2703,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     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 ||

diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 4f7d15fa507f653b754dae9e8d247b02b81e2c2b..3238a6408c1e361f1bfa24f3f6643df7651a7a60 100644 (file)
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -485,6 +485,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   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);

diff --git a/test/CodeGen/available-externally-suppress.c b/test/CodeGen/available-externally-suppress.c
index 390d2017884a929e61fba46db68224ede01ae5c0..a25a28271277ddd8bd66aa542b5241832a8fb2d1 100644 (file)
--- a/test/CodeGen/available-externally-suppress.c
+++ b/test/CodeGen/available-externally-suppress.c
@@ -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)) f1(int x) {
 }
 
 // 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);
 }