[mips] Teach the driver to accept -m(no-)gpopt.

This patch teaches the driver to pass -mgpopt by default to the backend when it
is supported, i.e. we are using -mno-abicalls.

Reviewers: atanasyan, slthakur

Differential Revision: https://reviews.llvm.org/D35548


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@308431 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/Driver/ToolChains/Clang.cpp b/lib/Driver/ToolChains/Clang.cpp
index b82cc2d4fa..7f2e64cbf8 100644
--- a/lib/Driver/ToolChains/Clang.cpp
+++ b/lib/Driver/ToolChains/Clang.cpp
@@ -1462,6 +1462,32 @@ void Clang::AddMIPSTargetArgs(const ArgList &Args,
     A->claim();
   }
 
+  Arg *GPOpt = Args.getLastArg(options::OPT_mgpopt, options::OPT_mno_gpopt);
+  Arg *ABICalls = Args.getLastArg(options::OPT_mabicalls, options::OPT_mno_abicalls);
+
+  // -mabicalls is the default for many MIPS environments, even with -fno-pic.
+  // -mgpopt is the default for static, -fno-pic environments but these two
+  // options conflict. We want to be certain that -mno-abicalls -mgpopt is
+  // the only case where -mllvm -mgpopt is passed.
+  // NOTE: We need a warning here or in the backend to warn when -mgpopt is
+  //       passed explicitly when compiling something with -mabicalls
+  //       (implictly) in affect. Currently the warning is in the backend.
+  bool NoABICalls =
+      ABICalls && ABICalls->getOption().matches(options::OPT_mno_abicalls);
+  bool WantGPOpt = GPOpt && GPOpt->getOption().matches(options::OPT_mgpopt);
+  if (NoABICalls && (!GPOpt || WantGPOpt)) {
+      CmdArgs.push_back("-mllvm");
+      CmdArgs.push_back("-mgpopt=1");
+  } else {
+      CmdArgs.push_back("-mllvm");
+      CmdArgs.push_back("-mgpopt=0");
+      if ((!ABICalls || (!NoABICalls && ABICalls)) && (!GPOpt || WantGPOpt))
+        D.Diag(diag::warn_drv_unsupported_gpopt) << (ABICalls ? 0 : 1);
+  }
+
+  if (GPOpt)
+    GPOpt->claim();
+
   if (Arg *A = Args.getLastArg(options::OPT_mcompact_branches_EQ)) {
     StringRef Val = StringRef(A->getValue());
     if (mips::hasCompactBranches(CPUName)) {