Index: lib/Target/Mips/MipsFastISel.cpp
===================================================================
--- lib/Target/Mips/MipsFastISel.cpp
+++ lib/Target/Mips/MipsFastISel.cpp
@@ -4,6 +4,7 @@
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
 #include "llvm/CodeGen/FastISel.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/IR/GlobalAlias.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/Target/TargetInstrInfo.h"
@@ -11,6 +12,7 @@
 #include "MipsRegisterInfo.h"
 #include "MipsISelLowering.h"
 #include "MipsMachineFunction.h"
+#include "MipsRegisterInfo.h"
 #include "MipsSubtarget.h"
 #include "MipsTargetMachine.h"
 
@@ -1007,14 +1009,92 @@
 }
 
 bool MipsFastISel::selectRet(const Instruction *I) {
+  const Function &F = *I->getParent()->getParent();
   const ReturnInst *Ret = cast<ReturnInst>(I);
 
   if (!FuncInfo.CanLowerReturn)
     return false;
+
+  if (F.isVarArg())
+      return false;
+
+  // Build a list of return value registers.
+  SmallVector<unsigned, 4> RetRegs;
+
   if (Ret->getNumOperands() > 0) {
-    return false;
+    CallingConv::ID CC = F.getCallingConv();
+    SmallVector<ISD::OutputArg, 4> Outs;
+    GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI);
+    // Analyze operands of the call, assigning locations to each operand.
+    SmallVector<CCValAssign, 16> ValLocs;
+    CCState CCInfo(CC, F.isVarArg(), *FuncInfo.MF, ValLocs, I->getContext());
+    CCAssignFn *RetCC = RetCC_Mips;
+    CCInfo.AnalyzeReturn(Outs, RetCC);
+
+    // Only handle a single return value for now.
+    if (ValLocs.size() != 1)
+      return false;
+
+    CCValAssign &VA = ValLocs[0];
+    const Value *RV = Ret->getOperand(0);
+
+    // Don't bother handling odd stuff for now.
+    if ((VA.getLocInfo() != CCValAssign::Full) &&
+        (VA.getLocInfo() != CCValAssign::BCvt))
+      return false;
+
+    // Only handle register returns for now.
+    if (!VA.isRegLoc())
+      return false;
+
+    unsigned Reg = getRegForValue(RV);
+    if (Reg == 0)
+      return false;
+
+    unsigned SrcReg = Reg + VA.getValNo();
+    unsigned DestReg = VA.getLocReg();
+    // Avoid a cross-class copy. This is very unlikely.
+    if (!MRI.getRegClass(SrcReg)->contains(DestReg))
+      return false;
+
+    EVT RVEVT = TLI.getValueType(RV->getType());
+    if (!RVEVT.isSimple())
+      return false;
+
+    // Vectors (of > 1 lane) in big endian need tricky handling.
+    if (RVEVT.isVector() && RVEVT.getVectorNumElements() > 1 &&
+        !Subtarget->isLittle())
+      return false;
+
+    MVT RVVT = RVEVT.getSimpleVT();
+    if (RVVT == MVT::f128)
+      return false;
+
+    MVT DestVT = VA.getValVT();
+    // Special handling for extended integers.
+    if (RVVT != DestVT) {
+      if (RVVT != MVT::i1 && RVVT != MVT::i8 && RVVT != MVT::i16)
+        return false;
+
+      if (!Outs[0].Flags.isZExt() && !Outs[0].Flags.isSExt())
+        return false;
+
+      bool IsZExt = Outs[0].Flags.isZExt();
+      SrcReg = emitIntExt(RVVT, SrcReg, DestVT, IsZExt);
+      if (SrcReg == 0)
+        return false;
+    }
+
+    // Make the copy.
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc,
+            TII.get(TargetOpcode::COPY), DestReg).addReg(SrcReg);
+
+    // Add register to return instruction.
+    RetRegs.push_back(VA.getLocReg());
   }
-  emitInst(Mips::RetRA);
+  MachineInstrBuilder MIB = emitInst(Mips::RetRA);
+  for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
+    MIB.addReg(RetRegs[i], RegState::Implicit);
   return true;
 }
 
@@ -1139,7 +1219,8 @@
 unsigned MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
                                   bool isZExt) {
   unsigned DestReg = createResultReg(&Mips::GPR32RegClass);
-  return emitIntExt(SrcVT, SrcReg, DestVT, DestReg, isZExt);
+  bool Success = emitIntExt(SrcVT, SrcReg, DestVT, DestReg, isZExt);
+  return Success? DestReg: 0;
 }
 
 bool MipsFastISel::fastSelectInstruction(const Instruction *I) {