Fix handling of double precision loads and stores when Mips1 is targeted.

Mips1 does not support double precision loads or stores, therefore two single
precision loads or stores must be used in place of these instructions. This 
patch treats double precision loads and stores as if they are legal
instructions until MCInstLowering, instead of generating the single precision
instructions during instruction selection or Prolog/Epilog code insertion.

Without the changes made in this patch, llc produces code that has the same 
problem described in r137484 or bails out when
MipsInstrInfo::storeRegToStackSlot or loadRegFromStackSlot is called before
register allocation.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137711 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/MipsMCInstLower.h

@@ -9,6 +9,7 @@
 
 #ifndef MIPSMCINSTLOWER_H
 #define MIPSMCINSTLOWER_H
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/Support/Compiler.h"
 
@@ -34,6 +35,9 @@ public:
   MipsMCInstLower(Mangler *mang, const MachineFunction &MF,
                   MipsAsmPrinter &asmprinter);  
   void Lower(const MachineInstr *MI, MCInst &OutMI) const;
+  void LowerMips1F64LoadStore(const MachineInstr *MI, unsigned Opc,
+                              SmallVector<MCInst, 4>& MCInsts,
+                              bool isLittle, const unsigned *SubReg) const;
 private:
   MCOperand LowerSymbolOperand(const MachineOperand &MO,
                                MachineOperandType MOTy, unsigned Offset) const;