1 files changed, 18 insertions, 15 deletions

diff --git a/lib/Target/Mips/MipsRegisterInfo.cpp b/lib/Target/Mips/MipsRegisterInfo.cpp
index ab32bc4a66..13893a1e31 100644
--- a/lib/Target/Mips/MipsRegisterInfo.cpp
+++ b/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -81,13 +81,13 @@ MipsRegisterInfo::getCallPreservedMask(CallingConv::ID) const {
 BitVector MipsRegisterInfo::
 getReservedRegs(const MachineFunction &MF) const {
   static const uint16_t ReservedCPURegs[] = {
-    Mips::ZERO, Mips::AT,
+    Mips::ZERO,
     Mips::T6, Mips::T7, Mips::T8,          // @LOCALMOD: reserved for PNaCl use
     Mips::K0, Mips::K1, Mips::SP
   };
 
   static const uint16_t ReservedCPU64Regs[] = {
-    Mips::ZERO_64, Mips::AT_64, Mips::K0_64, Mips::K1_64, Mips::SP_64
+    Mips::ZERO_64, Mips::K0_64, Mips::K1_64, Mips::SP_64
   };
 
   BitVector Reserved(getNumRegs());
@@ -96,29 +96,28 @@ getReservedRegs(const MachineFunction &MF) const {
   for (unsigned I = 0; I < array_lengthof(ReservedCPURegs); ++I)
     Reserved.set(ReservedCPURegs[I]);
 
-  if (Subtarget.hasMips64()) {
-    for (unsigned I = 0; I < array_lengthof(ReservedCPU64Regs); ++I)
-      Reserved.set(ReservedCPU64Regs[I]);
+  for (unsigned I = 0; I < array_lengthof(ReservedCPU64Regs); ++I)
+    Reserved.set(ReservedCPU64Regs[I]);
 
+  if (Subtarget.hasMips64()) {
     // Reserve all registers in AFGR64.
     for (RegIter Reg = Mips::AFGR64RegClass.begin(),
          EReg = Mips::AFGR64RegClass.end(); Reg != EReg; ++Reg)
       Reserved.set(*Reg);
   } else {
-    // Reserve all registers in CPU64Regs & FGR64.
-    for (RegIter Reg = Mips::CPU64RegsRegClass.begin(),
-         EReg = Mips::CPU64RegsRegClass.end(); Reg != EReg; ++Reg)
-      Reserved.set(*Reg);
-
+    // Reserve all registers in FGR64.
     for (RegIter Reg = Mips::FGR64RegClass.begin(),
          EReg = Mips::FGR64RegClass.end(); Reg != EReg; ++Reg)
       Reserved.set(*Reg);
   }
-
   // Reserve FP if this function should have a dedicated frame pointer register.
   if (MF.getTarget().getFrameLowering()->hasFP(MF)) {
-    Reserved.set(Mips::FP);
-    Reserved.set(Mips::FP_64);
+    if (Subtarget.inMips16Mode())
+      Reserved.set(Mips::S0);
+    else {
+      Reserved.set(Mips::FP);
+      Reserved.set(Mips::FP_64);
+    }
   }
 
   // Reserve hardware registers.
@@ -188,8 +187,12 @@ getFrameRegister(const MachineFunction &MF) const {
   const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
   bool IsN64 = Subtarget.isABI_N64();
 
-  return TFI->hasFP(MF) ? (IsN64 ? Mips::FP_64 : Mips::FP) :
-                          (IsN64 ? Mips::SP_64 : Mips::SP);
+  if (Subtarget.inMips16Mode())
+    return TFI->hasFP(MF) ? Mips::S0 : Mips::SP;
+  else
+    return TFI->hasFP(MF) ? (IsN64 ? Mips::FP_64 : Mips::FP) :
+                            (IsN64 ? Mips::SP_64 : Mips::SP);
+
 }
 
 unsigned MipsRegisterInfo::