MIPS: Use -G option to specify MIPS section threshold. Translate it
to the -mllvm -mips-ssection-threshold=<value> pair and pass to the frontend.
The patch suggested by Carl Norum.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162697 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index 1142913..ccfa69a 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -941,6 +941,13 @@
   AddTargetFeature(Args, CmdArgs,
                    options::OPT_mdspr2, options::OPT_mno_dspr2,
                    "dspr2");
+
+  if (Arg *A = Args.getLastArg(options::OPT_G)) {
+    StringRef v = A->getValue(Args);
+    CmdArgs.push_back("-mllvm");
+    CmdArgs.push_back(Args.MakeArgString("-mips-ssection-threshold=" + v));
+    A->claim();
+  }
 }
 
 /// getPPCTargetCPU - Get the (LLVM) name of the PowerPC cpu we are targeting.
diff --git a/test/Driver/mips-features.c b/test/Driver/mips-features.c
index 5be2683..28048e7 100644
--- a/test/Driver/mips-features.c
+++ b/test/Driver/mips-features.c
@@ -37,3 +37,9 @@
 // RUN:     -mdspr2 -mno-dspr2 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-NOMDSPR2 %s
 // CHECK-NOMDSPR2: "-target-feature" "-dspr2"
+//
+// -G
+// RUN: %clang -target mips-linux-gnu -### -c %s \
+// RUN:     -G 16 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MIPS-G %s
+// CHECK-MIPS-G: "-mllvm" "-mips-ssection-threshold=16"