[driver][mips] Pass long-calls feature flag to the MIPS backend

Check the `-mlong-calls` command line option and pass the `long-calls`
feature flag to the backend. Handling of this feature flag in the backend
needs to be implemented by a separate commit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@307386 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Driver/ToolChains/Arch/Mips.cpp

@@ -299,6 +299,8 @@ void mips::getMIPSTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                    options::OPT_modd_spreg, "nooddspreg");
   AddTargetFeature(Args, Features, options::OPT_mno_madd4, options::OPT_mmadd4,
                    "nomadd4");
+  AddTargetFeature(Args, Features, options::OPT_mlong_calls,
+                   options::OPT_mno_long_calls, "long-calls");
 }
 
 mips::NanEncoding mips::getSupportedNanEncoding(StringRef &CPU) {

test/Driver/mips-features.c

@@ -247,3 +247,14 @@
 // RUN:   | FileCheck --check-prefix=CHECK-IMG-SINGLEFLOAT-FPXX %s
 // CHECK-IMG-SINGLEFLOAT-FPXX: "-target-feature" "+single-float"
 // CHECK-IMG-SINGLEFLOAT-FPXX: "-target-feature" "+fpxx"
+
+// -mlong-call
+// RUN: %clang -target mips-img-linux-gnu -### -c %s -mlong-calls 2>&1 \
+// RUN:   | FileCheck --check-prefix=LONG-CALLS-ON %s
+// RUN: %clang -target mips-img-linux-gnu -### -c %s -mno-long-calls 2>&1 \
+// RUN:   | FileCheck --check-prefix=LONG-CALLS-OFF %s
+// RUN: %clang -target mips-img-linux-gnu -### -c %s 2>&1 \
+// RUN:   | FileCheck --check-prefix=LONG-CALLS-DEF %s
+// LONG-CALLS-ON: "-target-feature" "+long-calls"
+// LONG-CALLS-OFF: "-target-feature" "-long-calls"
+// LONG-CALLS-DEF-NOT: "long-calls"