diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 2ff369c..088e669 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -3007,9 +3007,9 @@
   SmallVector<CCValAssign, 16> ArgLocs;
   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
                  getTargetMachine(), ArgLocs, *DAG.getContext());
-  MipsCC MipsCCInfo(CallConv, isVarArg, IsO32, CCInfo);
+  MipsCC MipsCCInfo(CallConv, IsO32, CCInfo);
 
-  MipsCCInfo.analyzeCallOperands(Outs);
+  MipsCCInfo.analyzeCallOperands(Outs, isVarArg);
 
   // Get a count of how many bytes are to be pushed on the stack.
   unsigned NextStackOffset = CCInfo.getNextStackOffset();
@@ -3294,7 +3294,7 @@
   SmallVector<CCValAssign, 16> ArgLocs;
   CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
                  getTargetMachine(), ArgLocs, *DAG.getContext());
-  MipsCC MipsCCInfo(CallConv, isVarArg, IsO32, CCInfo);
+  MipsCC MipsCCInfo(CallConv, IsO32, CCInfo);
 
   MipsCCInfo.analyzeFormalArguments(Ins);
   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
@@ -3776,40 +3776,21 @@
   return TargetLowering::getJumpTableEncoding();
 }
 
-MipsTargetLowering::MipsCC::MipsCC(CallingConv::ID CallConv, bool IsVarArg,
-                                   bool IsO32, CCState &Info) : CCInfo(Info) {
-  UseRegsForByval = true;
-
-  if (IsO32) {
-    RegSize = 4;
-    NumIntArgRegs = array_lengthof(O32IntRegs);
-    ReservedArgArea = 16;
-    IntArgRegs = ShadowRegs = O32IntRegs;
-    FixedFn = VarFn = CC_MipsO32;
-  } else {
-    RegSize = 8;
-    NumIntArgRegs = array_lengthof(Mips64IntRegs);
-    ReservedArgArea = 0;
-    IntArgRegs = Mips64IntRegs;
-    ShadowRegs = Mips64DPRegs;
-    FixedFn = CC_MipsN;
-    VarFn = IsVarArg ? CC_MipsN_VarArg : CC_MipsN;
-  }
-
-  if (CallConv == CallingConv::Fast) {
-    assert(!IsVarArg);
-    UseRegsForByval = false;
-    ReservedArgArea = 0;
-    FixedFn = VarFn = CC_Mips_FastCC;
-  }
-
+MipsTargetLowering::MipsCC::MipsCC(CallingConv::ID CC, bool IsO32_,
+                                   CCState &Info)
+  : CCInfo(Info), CallConv(CC), IsO32(IsO32_) {
   // Pre-allocate reserved argument area.
-  CCInfo.AllocateStack(ReservedArgArea, 1);
+  CCInfo.AllocateStack(reservedArgArea(), 1);
 }
 
 void MipsTargetLowering::MipsCC::
-analyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Args) {
+analyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Args,
+                    bool IsVarArg) {
+  assert((CallConv != CallingConv::Fast || !IsVarArg) &&
+         "CallingConv::Fast shouldn't be used for vararg functions.");
+
   unsigned NumOpnds = Args.size();
+  llvm::CCAssignFn *FixedFn = fixedArgFn(), *VarFn = varArgFn();
 
   for (unsigned I = 0; I != NumOpnds; ++I) {
     MVT ArgVT = Args[I].VT;
@@ -3821,10 +3802,10 @@
       continue;
     }
 
-    if (Args[I].IsFixed)
-      R = FixedFn(I, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
-    else
+    if (IsVarArg && !Args[I].IsFixed)
       R = VarFn(I, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
+    else
+      R = FixedFn(I, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
 
     if (R) {
 #ifndef NDEBUG
@@ -3839,6 +3820,7 @@
 void MipsTargetLowering::MipsCC::
 analyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Args) {
   unsigned NumArgs = Args.size();
+  llvm::CCAssignFn *FixedFn = fixedArgFn();
 
   for (unsigned I = 0; I != NumArgs; ++I) {
     MVT ArgVT = Args[I].VT;
@@ -3868,11 +3850,12 @@
   assert(ArgFlags.getByValSize() && "Byval argument's size shouldn't be 0.");
 
   struct ByValArgInfo ByVal;
+  unsigned RegSize = regSize();
   unsigned ByValSize = RoundUpToAlignment(ArgFlags.getByValSize(), RegSize);
   unsigned Align = std::min(std::max(ArgFlags.getByValAlign(), RegSize),
                             RegSize * 2);
 
-  if (UseRegsForByval)
+  if (useRegsForByval())
     allocateRegs(ByVal, ByValSize, Align);
 
   // Allocate space on caller's stack.
@@ -3883,9 +3866,38 @@
   ByValArgs.push_back(ByVal);
 }
 
+unsigned MipsTargetLowering::MipsCC::numIntArgRegs() const {
+  return IsO32 ? array_lengthof(O32IntRegs) : array_lengthof(Mips64IntRegs);
+}
+
+unsigned MipsTargetLowering::MipsCC::reservedArgArea() const {
+  return (IsO32 && (CallConv != CallingConv::Fast)) ? 16 : 0;
+}
+
+const uint16_t *MipsTargetLowering::MipsCC::intArgRegs() const {
+  return IsO32 ? O32IntRegs : Mips64IntRegs;
+}
+
+llvm::CCAssignFn *MipsTargetLowering::MipsCC::fixedArgFn() const {
+  if (CallConv == CallingConv::Fast)
+    return CC_Mips_FastCC;
+
+  return IsO32 ? CC_MipsO32 : CC_MipsN;
+}
+
+llvm::CCAssignFn *MipsTargetLowering::MipsCC::varArgFn() const {
+  return IsO32 ? CC_MipsO32 : CC_MipsN_VarArg;
+}
+
+const uint16_t *MipsTargetLowering::MipsCC::shadowRegs() const {
+  return IsO32 ? O32IntRegs : Mips64DPRegs;
+}
+
 void MipsTargetLowering::MipsCC::allocateRegs(ByValArgInfo &ByVal,
                                               unsigned ByValSize,
                                               unsigned Align) {
+  unsigned RegSize = regSize(), NumIntArgRegs = numIntArgRegs();
+  const uint16_t *IntArgRegs = intArgRegs(), *ShadowRegs = shadowRegs();
   assert(!(ByValSize % RegSize) && !(Align % RegSize) &&
          "Byval argument's size and alignment should be a multiple of"
          "RegSize.");
diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h
index 00aa282..3b46355 100644
--- a/lib/Target/Mips/MipsISelLowering.h
+++ b/lib/Target/Mips/MipsISelLowering.h
@@ -201,53 +201,57 @@
     /// arguments and inquire about calling convention information.
     class MipsCC {
     public:
-      MipsCC(CallingConv::ID CallConv, bool IsVarArg, bool IsO32,
-             CCState &Info);
+      MipsCC(CallingConv::ID CallConv, bool IsO32, CCState &Info);
 
-      void analyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs);
+      void analyzeCallOperands(const SmallVectorImpl<ISD::OutputArg> &Outs,
+                               bool IsVarArg);
       void analyzeFormalArguments(const SmallVectorImpl<ISD::InputArg> &Ins);
-      void handleByValArg(unsigned ValNo, MVT ValVT, MVT LocVT,
-                          CCValAssign::LocInfo LocInfo,
-                          ISD::ArgFlagsTy ArgFlags);
-
       const CCState &getCCInfo() const { return CCInfo; }
 
       /// hasByValArg - Returns true if function has byval arguments.
       bool hasByValArg() const { return !ByValArgs.empty(); }
 
-      /// useRegsForByval - Returns true if the calling convention allows the
-      /// use of registers to pass byval arguments.
-      bool useRegsForByval() const { return UseRegsForByval; }
-
       /// regSize - Size (in number of bits) of integer registers.
-      unsigned regSize() const { return RegSize; }
+      unsigned regSize() const { return IsO32 ? 4 : 8; }
 
       /// numIntArgRegs - Number of integer registers available for calls.
-      unsigned numIntArgRegs() const { return NumIntArgRegs; }
+      unsigned numIntArgRegs() const;
 
       /// reservedArgArea - The size of the area the caller reserves for
       /// register arguments. This is 16-byte if ABI is O32.
-      unsigned reservedArgArea() const { return ReservedArgArea; }
+      unsigned reservedArgArea() const;
 
-      /// intArgRegs - Pointer to array of integer registers.
-      const uint16_t *intArgRegs() const { return IntArgRegs; }
+      /// Return pointer to array of integer argument registers.
+      const uint16_t *intArgRegs() const;
 
       typedef SmallVector<ByValArgInfo, 2>::const_iterator byval_iterator;
       byval_iterator byval_begin() const { return ByValArgs.begin(); }
       byval_iterator byval_end() const { return ByValArgs.end(); }
 
     private:
+      void handleByValArg(unsigned ValNo, MVT ValVT, MVT LocVT,
+                          CCValAssign::LocInfo LocInfo,
+                          ISD::ArgFlagsTy ArgFlags);
+
+      /// useRegsForByval - Returns true if the calling convention allows the
+      /// use of registers to pass byval arguments.
+      bool useRegsForByval() const { return CallConv != CallingConv::Fast; }
+
+      /// Return the function that analyzes fixed argument list functions.
+      llvm::CCAssignFn *fixedArgFn() const;
+
+      /// Return the function that analyzes variable argument list functions.
+      llvm::CCAssignFn *varArgFn() const;
+
+      const uint16_t *shadowRegs() const;
+
       void allocateRegs(ByValArgInfo &ByVal, unsigned ByValSize,
                         unsigned Align);
 
       CCState &CCInfo;
-      bool UseRegsForByval;
-      unsigned RegSize;
-      unsigned NumIntArgRegs;
-      unsigned ReservedArgArea;
-      const uint16_t *IntArgRegs, *ShadowRegs;
+      CallingConv::ID CallConv;
+      bool IsO32;
       SmallVector<ByValArgInfo, 2> ByValArgs;
-      llvm::CCAssignFn *FixedFn, *VarFn;
     };
 
     // Subtarget Info