[MachineOutliner] Properly pass -moutline along to the toolchain

This moves the LTO-specific code for outlining from ToolChains/Clang.cpp to
ToolChains/Darwin.cpp. Passing -mllvm flags isn't sufficient for making sure
that the specified pass will actually run in LTO. This makes sure that when
-moutline is passed, the MachineOutliner will actually be added to the LTO
pass pipeline as expected.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@336471 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index 11f77096ae..9205dd52de 100644
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/lib/Driver/ToolChains/Darwin.cpp
@@ -479,6 +479,18 @@ void darwin::Linker::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
+  // Propagate the -moutline flag to the linker in LTO.
+  if (Args.hasFlag(options::OPT_moutline, options::OPT_mno_outline, false)) {
+    if (getMachOToolChain().getMachOArchName(Args) == "arm64") {
+      CmdArgs.push_back("-mllvm");
+      CmdArgs.push_back("-enable-machine-outliner");
+
+      // Outline from linkonceodr functions by default in LTO.
+      CmdArgs.push_back("-mllvm");
+      CmdArgs.push_back("-enable-linkonceodr-outlining");
+    }
+  }
+
   // It seems that the 'e' option is completely ignored for dynamic executables
   // (the default), and with static executables, the last one wins, as expected.
   Args.AddAllArgs(CmdArgs, {options::OPT_d_Flag, options::OPT_s, options::OPT_t,