[clang] 0c41b1c - [Driver][MachineOutliner] Support outlining option with LTO

[Yvan Roux via cfe-commits]

Author: Yvan Roux
Date: 2021-01-06T16:01:38+01:00
New Revision: 0c41b1c9f93c09966b87126820d3cf41d8eebbf9

URL: https://github.com/llvm/llvm-project/commit/0c41b1c9f93c09966b87126820d3cf41d8eebbf9
DIFF: https://github.com/llvm/llvm-project/commit/0c41b1c9f93c09966b87126820d3cf41d8eebbf9.diff

LOG: [Driver][MachineOutliner] Support outlining option with LTO

This patch propagates the -moutline flag when LTO is enabled and avoids
passing it explicitly to the linker plugin.

Differential Revision: https://reviews.llvm.org/D93385

Added: 
    clang/test/Driver/arm-machine-outliner.c

Modified: 
    clang/lib/Driver/ToolChains/Clang.cpp
    clang/lib/Driver/ToolChains/CommonArgs.cpp
    clang/lib/Driver/ToolChains/CommonArgs.h

Removed: 
    


################################################################################
diff  --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index f8b9bf25373e..917601836c0a 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -6396,26 +6396,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
                     options::OPT_fno_cxx_static_destructors, true))
     CmdArgs.push_back("-fno-c++-static-destructors");
 
-  if (Arg *A = Args.getLastArg(options::OPT_moutline,
-                               options::OPT_mno_outline)) {
-    if (A->getOption().matches(options::OPT_moutline)) {
-      // We only support -moutline in AArch64 and ARM targets right now. If
-      // we're not compiling for these, emit a warning and ignore the flag.
-      // Otherwise, add the proper mllvm flags.
-      if (!(Triple.isARM() || Triple.isThumb() ||
-            Triple.getArch() == llvm::Triple::aarch64 ||
-            Triple.getArch() == llvm::Triple::aarch64_32)) {
-        D.Diag(diag::warn_drv_moutline_unsupported_opt) << Triple.getArchName();
-      } else {
-        CmdArgs.push_back("-mllvm");
-        CmdArgs.push_back("-enable-machine-outliner");
-      }
-    } else {
-      // Disable all outlining behaviour.
-      CmdArgs.push_back("-mllvm");
-      CmdArgs.push_back("-enable-machine-outliner=never");
-    }
-  }
+  addMachineOutlinerArgs(D, Args, CmdArgs, Triple, /*IsLTO=*/false);
 
   if (Arg *A = Args.getLastArg(options::OPT_moutline_atomics,
                                options::OPT_mno_outline_atomics)) {

diff  --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index fe5e7536d380..6a95aa5ec628 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -624,6 +624,9 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
 
   // Handle remarks hotness/threshold related options.
   renderRemarksHotnessOptions(Args, CmdArgs);
+
+  addMachineOutlinerArgs(D, Args, CmdArgs, ToolChain.getEffectiveTriple(),
+                         /*IsLTO=*/true);
 }
 
 void tools::addArchSpecificRPath(const ToolChain &TC, const ArgList &Args,
@@ -1586,3 +1589,36 @@ unsigned tools::getOrCheckAMDGPUCodeObjectVersion(
   }
   return CodeObjVer;
 }
+
+void tools::addMachineOutlinerArgs(const Driver &D,
+                                   const llvm::opt::ArgList &Args,
+                                   llvm::opt::ArgStringList &CmdArgs,
+                                   const llvm::Triple &Triple, bool IsLTO) {
+  auto addArg = [&, IsLTO](const Twine &Arg) {
+    if (IsLTO) {
+      CmdArgs.push_back(Args.MakeArgString("-plugin-opt=" + Arg));
+    } else {
+      CmdArgs.push_back("-mllvm");
+      CmdArgs.push_back(Args.MakeArgString(Arg));
+    }
+  };
+
+  if (Arg *A = Args.getLastArg(options::OPT_moutline,
+                               options::OPT_mno_outline)) {
+    if (A->getOption().matches(options::OPT_moutline)) {
+      // We only support -moutline in AArch64 and ARM targets right now. If
+      // we're not compiling for these, emit a warning and ignore the flag.
+      // Otherwise, add the proper mllvm flags.
+      if (!(Triple.isARM() || Triple.isThumb() ||
+            Triple.getArch() == llvm::Triple::aarch64 ||
+            Triple.getArch() == llvm::Triple::aarch64_32)) {
+        D.Diag(diag::warn_drv_moutline_unsupported_opt) << Triple.getArchName();
+      } else {
+        addArg(Twine("-enable-machine-outliner"));
+      }
+    } else {
+      // Disable all outlining behaviour.
+      addArg(Twine("-enable-machine-outliner=never"));
+    }
+  }
+}

diff  --git a/clang/lib/Driver/ToolChains/CommonArgs.h b/clang/lib/Driver/ToolChains/CommonArgs.h
index 9a365f376022..187c340d1c3c 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.h
+++ b/clang/lib/Driver/ToolChains/CommonArgs.h
@@ -141,6 +141,10 @@ void addX86AlignBranchArgs(const Driver &D, const llvm::opt::ArgList &Args,
 unsigned getOrCheckAMDGPUCodeObjectVersion(const Driver &D,
                                            const llvm::opt::ArgList &Args,
                                            bool Diagnose = false);
+
+void addMachineOutlinerArgs(const Driver &D, const llvm::opt::ArgList &Args,
+                            llvm::opt::ArgStringList &CmdArgs,
+                            const llvm::Triple &Triple, bool IsLTO);
 } // end namespace tools
 } // end namespace driver
 } // end namespace clang

diff  --git a/clang/test/Driver/arm-machine-outliner.c b/clang/test/Driver/arm-machine-outliner.c
new file mode 100644
index 000000000000..6ac82838323a
--- /dev/null
+++ b/clang/test/Driver/arm-machine-outliner.c
@@ -0,0 +1,9 @@
+// REQUIRES: arm-registered-target
+// RUN: %clang -target armv7-linux-gnueabihf -moutline -c %s -### 2>&1 | FileCheck %s -check-prefix=ON
+// ON: "-mllvm" "-enable-machine-outliner"
+// RUN: %clang -target armv7-linux-gnueabihf -flto -moutline %s -### 2>&1 | FileCheck %s -check-prefix=ON-LTO
+// ON-LTO: "-plugin-opt=-enable-machine-outliner"
+// RUN: %clang -target armv7-linux-gnueabihf -moutline -mno-outline -c %s -### 2>&1 | FileCheck %s -check-prefix=OFF
+// OFF: "-mllvm" "-enable-machine-outliner=never"
+// RUN: %clang -target armv7-linux-gnueabihf -flto -moutline -mno-outline %s -### 2>&1 | FileCheck %s -check-prefix=OFF-LTO
+// OFF-LTO: "-plugin-opt=-enable-machine-outliner=never"