Index: cfe/trunk/include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticDriverKinds.td
+++ cfe/trunk/include/clang/Basic/DiagnosticDriverKinds.td
@@ -292,6 +292,10 @@
   "ignoring '-mgpopt' option as it cannot be used with %select{|the implicit"
   " usage of }0-mabicalls">,
   InGroup<UnsupportedGPOpt>;
+def warn_drv_unsupported_longcalls : Warning<
+  "ignoring '-mlong-calls' option as it is not currently supported with "
+  "%select{|the implicit usage of }0-mabicalls">,
+  InGroup<OptionIgnored>;
 def warn_drv_unsupported_abicalls : Warning<
   "ignoring '-mabicalls' option as it cannot be used with "
   "non position-independent code and the N64 ABI">,
Index: cfe/trunk/lib/Driver/ToolChains/Arch/Mips.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/Arch/Mips.cpp
+++ cfe/trunk/lib/Driver/ToolChains/Arch/Mips.cpp
@@ -245,6 +245,16 @@
   else
     Features.push_back("-noabicalls");
 
+  if (Arg *A = Args.getLastArg(options::OPT_mlong_calls,
+                               options::OPT_mno_long_calls)) {
+    if (A->getOption().matches(options::OPT_mno_long_calls))
+      Features.push_back("-long-calls");
+    else if (!UseAbiCalls)
+      Features.push_back("+long-calls");
+    else
+      D.Diag(diag::warn_drv_unsupported_longcalls) << (ABICallsArg ? 0 : 1);
+  }
+
   mips::FloatABI FloatABI = mips::getMipsFloatABI(D, Args);
   if (FloatABI == mips::FloatABI::Soft) {
     // FIXME: Note, this is a hack. We need to pass the selected float
@@ -309,8 +319,6 @@
 
   AddTargetFeature(Args, Features, options::OPT_mno_odd_spreg,
                    options::OPT_modd_spreg, "nooddspreg");
-  AddTargetFeature(Args, Features, options::OPT_mlong_calls,
-                   options::OPT_mno_long_calls, "long-calls");
   AddTargetFeature(Args, Features, options::OPT_mmt, options::OPT_mno_mt, "mt");
 }
 
Index: cfe/trunk/test/Driver/mips-features.c
===================================================================
--- cfe/trunk/test/Driver/mips-features.c
+++ cfe/trunk/test/Driver/mips-features.c
@@ -336,12 +336,16 @@
 // CHECK-IMG-SINGLEFLOAT-FPXX: "-target-feature" "+fpxx"
 
 // -mlong-call
-// RUN: %clang -target mips-img-linux-gnu -### -c %s -mlong-calls 2>&1 \
+// RUN: %clang -target mips-img-linux-gnu -### -c %s \
+// RUN:        -mno-abicalls -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: %clang -target mips-img-linux-gnu -### -c %s \
+// RUN:        -mno-abicalls -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
+// RUN: %clang -target mips-img-linux-gnu -### -c %s -mlong-calls 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"
Index: cfe/trunk/test/Driver/mips-longcalls-warning.c
===================================================================
--- cfe/trunk/test/Driver/mips-longcalls-warning.c
+++ cfe/trunk/test/Driver/mips-longcalls-warning.c
@@ -0,0 +1,6 @@
+// REQUIRES: mips-registered-target
+// RUN: %clang -### -c -target mips-mti-elf -mlong-calls %s 2>&1 | FileCheck -check-prefix=IMPLICIT %s
+// IMPLICIT: warning: ignoring '-mlong-calls' option as it is not currently supported with the implicit usage of -mabicalls
+
+// RUN: %clang -### -c -target mips-mti-elf -mlong-calls -mabicalls %s 2>&1 | FileCheck -check-prefix=EXPLICIT %s
+// EXPLICIT: warning: ignoring '-mlong-calls' option as it is not currently supported with -mabicalls