Index: cfe/trunk/lib/Basic/Targets.cpp
===================================================================
--- cfe/trunk/lib/Basic/Targets.cpp
+++ cfe/trunk/lib/Basic/Targets.cpp
@@ -7464,6 +7464,8 @@
   bool IsMicromips;
   bool IsNan2008;
   bool IsSingleFloat;
+  bool IsNoABICalls;
+  bool CanUseBSDABICalls;
   enum MipsFloatABI {
     HardFloat, SoftFloat
   } FloatABI;
@@ -7479,8 +7481,9 @@
 public:
   MipsTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
       : TargetInfo(Triple), IsMips16(false), IsMicromips(false),
-        IsNan2008(false), IsSingleFloat(false), FloatABI(HardFloat),
-        DspRev(NoDSP), HasMSA(false), HasFP64(false) {
+        IsNan2008(false), IsSingleFloat(false), IsNoABICalls(false),
+        CanUseBSDABICalls(false), FloatABI(HardFloat), DspRev(NoDSP),
+        HasMSA(false), HasFP64(false) {
     TheCXXABI.set(TargetCXXABI::GenericMIPS);
 
     setABI((getTriple().getArch() == llvm::Triple::mips ||
@@ -7489,6 +7492,9 @@
                : "n64");
 
     CPU = ABI == "o32" ? "mips32r2" : "mips64r2";
+
+    CanUseBSDABICalls = Triple.getOS() == llvm::Triple::FreeBSD ||
+                        Triple.getOS() == llvm::Triple::OpenBSD;
   }
 
   bool isNaN2008Default() const {
@@ -7669,6 +7675,12 @@
     } else
       llvm_unreachable("Invalid ABI.");
 
+    if (!IsNoABICalls) {
+      Builder.defineMacro("__mips_abicalls");
+      if (CanUseBSDABICalls)
+        Builder.defineMacro("__ABICALLS__");
+    }
+
     Builder.defineMacro("__REGISTER_PREFIX__", "");
 
     switch (FloatABI) {
@@ -7883,6 +7895,8 @@
         IsNan2008 = true;
       else if (Feature == "-nan2008")
         IsNan2008 = false;
+      else if (Feature == "+noabicalls")
+        IsNoABICalls = true;
     }
 
     setDataLayout();
Index: cfe/trunk/test/Preprocessor/init.c
===================================================================
--- cfe/trunk/test/Preprocessor/init.c
+++ cfe/trunk/test/Preprocessor/init.c
@@ -3040,6 +3040,7 @@
 // MIPS32BE:#define __llvm__ 1
 // MIPS32BE:#define __mips 32
 // MIPS32BE:#define __mips__ 1
+// MIPS32BE:#define __mips_abicalls 1
 // MIPS32BE:#define __mips_fpr 32
 // MIPS32BE:#define __mips_hard_float 1
 // MIPS32BE:#define __mips_o32 1
@@ -3246,6 +3247,7 @@
 // MIPS32EL:#define __llvm__ 1
 // MIPS32EL:#define __mips 32
 // MIPS32EL:#define __mips__ 1
+// MIPS32EL:#define __mips_abicalls 1
 // MIPS32EL:#define __mips_fpr 32
 // MIPS32EL:#define __mips_hard_float 1
 // MIPS32EL:#define __mips_o32 1
@@ -3555,6 +3557,7 @@
 // MIPSN32BE: #define __mips64 1
 // MIPSN32BE: #define __mips64__ 1
 // MIPSN32BE: #define __mips__ 1
+// MIPSN32BE: #define __mips_abicalls 1
 // MIPSN32BE: #define __mips_fpr 64
 // MIPSN32BE: #define __mips_hard_float 1
 // MIPSN32BE: #define __mips_isa_rev 2
@@ -3861,6 +3864,7 @@
 // MIPSN32EL: #define __mips64 1
 // MIPSN32EL: #define __mips64__ 1
 // MIPSN32EL: #define __mips__ 1
+// MIPSN32EL: #define __mips_abicalls 1
 // MIPSN32EL: #define __mips_fpr 64
 // MIPSN32EL: #define __mips_hard_float 1
 // MIPSN32EL: #define __mips_isa_rev 2
@@ -4073,6 +4077,7 @@
 // MIPS64BE:#define __mips64 1
 // MIPS64BE:#define __mips64__ 1
 // MIPS64BE:#define __mips__ 1
+// MIPS64BE:#define __mips_abicalls 1
 // MIPS64BE:#define __mips_fpr 64
 // MIPS64BE:#define __mips_hard_float 1
 // MIPS64BE:#define __mips_n64 1
@@ -4282,6 +4287,7 @@
 // MIPS64EL:#define __mips64 1
 // MIPS64EL:#define __mips64__ 1
 // MIPS64EL:#define __mips__ 1
+// MIPS64EL:#define __mips_abicalls 1
 // MIPS64EL:#define __mips_fpr 64
 // MIPS64EL:#define __mips_hard_float 1
 // MIPS64EL:#define __mips_n64 1
@@ -4513,6 +4519,45 @@
 // MIPS-XXR6:#define __mips_fpr 64
 // MIPS-XXR6:#define __mips_nan2008 1
 //
+// RUN: %clang_cc1 -target-cpu mips32 \
+// RUN:   -E -dM -triple=mips-unknown-netbsd -mrelocation-model pic < /dev/null \
+// RUN:   | FileCheck -match-full-lines -check-prefix MIPS-ABICALLS-NETBSD %s
+// MIPS-ABICALLS-NETBSD-NOT: #define __ABICALLS__ 1
+// MIPS-ABICALLS-NETBSD: #define __mips_abicalls 1
+//
+// RUN: %clang_cc1 -target-cpu mips64 \
+// RUN:   -E -dM -triple=mips64-unknown-netbsd -mrelocation-model pic < \
+// RUN:   /dev/null | FileCheck -match-full-lines \
+// RUN:   -check-prefix MIPS-ABICALLS-NETBSD64 %s
+// MIPS-ABICALLS-NETBSD64-NOT: #define __ABICALLS__ 1
+// MIPS-ABICALLS-NETBSD64: #define __mips_abicalls 1
+//
+// RUN: %clang_cc1 -target-cpu mips32 \
+// RUN:   -E -dM -triple=mips-unknown-freebsd -mrelocation-model pic < /dev/null \
+// RUN:   | FileCheck -match-full-lines -check-prefix MIPS-ABICALLS-FREEBSD %s
+// MIPS-ABICALLS-FREEBSD: #define __ABICALLS__ 1
+// MIPS-ABICALLS-FREEBSD: #define __mips_abicalls 1
+//
+// RUN: %clang_cc1 -target-cpu mips64 \
+// RUN:   -E -dM -triple=mips64-unknown-freebsd -mrelocation-model pic < \
+// RUN:   /dev/null | FileCheck -match-full-lines \
+// RUN:   -check-prefix MIPS-ABICALLS-FREEBSD64 %s
+// MIPS-ABICALLS-FREEBSD64: #define __ABICALLS__ 1
+// MIPS-ABICALLS-FREEBSD64: #define __mips_abicalls 1
+//
+// RUN: %clang_cc1 -target-cpu mips32 \
+// RUN:   -E -dM -triple=mips-unknown-openbsd -mrelocation-model pic < /dev/null \
+// RUN:   | FileCheck -match-full-lines -check-prefix MIPS-ABICALLS-OPENBSD %s
+// MIPS-ABICALLS-OPENBSD: #define __ABICALLS__ 1
+// MIPS-ABICALLS-OPENBSD: #define __mips_abicalls 1
+//
+// RUN: %clang_cc1 -target-cpu mips64 \
+// RUN:   -E -dM -triple=mips64-unknown-openbsd -mrelocation-model pic < \
+// RUN:   /dev/null | FileCheck -match-full-lines \
+// RUN:   -check-prefix MIPS-ABICALLS-OPENBSD64 %s
+// MIPS-ABICALLS-OPENBSD64: #define __ABICALLS__ 1
+// MIPS-ABICALLS-OPENBSD64: #define __mips_abicalls 1
+//
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=msp430-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MSP430 %s
 // RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=msp430-none-none < /dev/null | FileCheck -match-full-lines -check-prefix MSP430 -check-prefix MSP430-CXX %s
 //