[mips][microMIPS] Implement SWM16 and LWM16 instructions

Differential Revision: http://reviews.llvm.org/D5579

llvm-svn: 222901

7 files changed, 147 insertions, 0 deletions

diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index f458b5bf520..67725cb7ffa 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -809,6 +809,29 @@ public:
   bool isMemWithGRPMM16Base() const {
     return isMem() && getMemBase()->isMM16AsmReg();
   }
+  template <unsigned Bits> bool isMemWithUimmOffsetSP() const {
+    return isMem() && isConstantMemOff() && isUInt<Bits>(getConstantMemOff())
+      && getMemBase()->isRegIdx() && (getMemBase()->getGPR32Reg() == Mips::SP);
+  }
+  bool isRegList16() const {
+    if (!isRegList())
+      return false;
+
+    int Size = RegList.List->size();
+    if (Size < 2 || Size > 5 || *RegList.List->begin() != Mips::S0 ||
+        RegList.List->back() != Mips::RA)
+      return false;
+
+    int PrevReg = *RegList.List->begin();
+    for (int i = 1; i < Size - 1; i++) {
+      int Reg = (*(RegList.List))[i];
+      if ( Reg != PrevReg + 1)
+        return false;
+      PrevReg = Reg;
+    }
+
+    return true;
+  }
   bool isInvNum() const { return Kind == k_Immediate; }
   bool isLSAImm() const {
     if (!isConstantImm())
diff --git a/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp b/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
index 58a857b662a..878bc23dbab 100644
--- a/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
+++ b/llvm/lib/Target/Mips/Disassembler/MipsDisassembler.cpp
@@ -380,6 +380,10 @@ static DecodeStatus DecodeRegListOperand(MCInst &Inst, unsigned Insn,
                                          uint64_t Address,
                                          const void *Decoder);
 
+static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
+                                           uint64_t Address,
+                                           const void *Decoder);
+
 namespace llvm {
 extern Target TheMipselTarget, TheMipsTarget, TheMips64Target,
               TheMips64elTarget;
@@ -1609,3 +1613,23 @@ static DecodeStatus DecodeRegListOperand(MCInst &Inst,
 
   return MCDisassembler::Success;
 }
+
+static DecodeStatus DecodeRegListOperand16(MCInst &Inst, unsigned Insn,
+                                           uint64_t Address,
+                                           const void *Decoder) {
+  unsigned Regs[] = {Mips::S0, Mips::S1, Mips::S2, Mips::S3};
+  unsigned RegNum;
+
+  unsigned RegLst = fieldFromInstruction(Insn, 4, 2);
+  // Empty register lists are not allowed.
+  if (RegLst == 0)
+    return MCDisassembler::Fail;
+
+  RegNum = RegLst & 0x3;
+  for (unsigned i = 0; i < RegNum - 1; i++)
+    Inst.addOperand(MCOperand::CreateReg(Regs[i]));
+
+  Inst.addOperand(MCOperand::CreateReg(Mips::RA));
+
+  return MCDisassembler::Success;
+}
diff --git a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
index ab6b22562ce..e8366290c16 100644
--- a/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
+++ b/llvm/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
@@ -233,6 +233,8 @@ printMemOperand(const MCInst *MI, int opNum, raw_ostream &O) {
     break;
   case Mips::SWM32_MM:
   case Mips::LWM32_MM:
+  case Mips::SWM16_MM:
+  case Mips::LWM16_MM:
     opNum = MI->getNumOperands() - 2;
     break;
   }
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
index 6cd1eb2e622..521ef0d0b69 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.cpp
@@ -699,6 +699,30 @@ getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
   return (OffBits & 0x0FFF) | RegBits;
 }
 
+unsigned MipsMCCodeEmitter::
+getMemEncodingMMImm4sp(const MCInst &MI, unsigned OpNo,
+                       SmallVectorImpl<MCFixup> &Fixups,
+                       const MCSubtargetInfo &STI) const {
+  // opNum can be invalid if instruction had reglist as operand
+  // MemOperand is always last operand of instruction (base + offset)
+  switch (MI.getOpcode()) {
+  default:
+    break;
+  case Mips::SWM16_MM:
+  case Mips::LWM16_MM:
+    OpNo = MI.getNumOperands() - 2;
+    break;
+  }
+
+  // Offset is encoded in bits 4-0.
+  assert(MI.getOperand(OpNo).isReg());
+  // Base register is always SP - thus it is not encoded.
+  assert(MI.getOperand(OpNo+1).isImm());
+  unsigned OffBits = getMachineOpValue(MI, MI.getOperand(OpNo+1), Fixups, STI);
+
+  return ((OffBits >> 2) & 0x0F);
+}
+
 unsigned
 MipsMCCodeEmitter::getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
                                       SmallVectorImpl<MCFixup> &Fixups,
@@ -830,4 +854,11 @@ MipsMCCodeEmitter::getRegisterListOpValue(const MCInst &MI, unsigned OpNo,
   return res;
 }
 
+unsigned
+MipsMCCodeEmitter::getRegisterListOpValue16(const MCInst &MI, unsigned OpNo,
+                                            SmallVectorImpl<MCFixup> &Fixups,
+                                            const MCSubtargetInfo &STI) const {
+  return (MI.getNumOperands() - 4);
+}
+
 #include "MipsGenMCCodeEmitter.inc"
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
index 24d0b45bb45..b557f740430 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsMCCodeEmitter.h
@@ -154,6 +154,9 @@ public:
   unsigned getMemEncodingMMImm12(const MCInst &MI, unsigned OpNo,
                                  SmallVectorImpl<MCFixup> &Fixups,
                                  const MCSubtargetInfo &STI) const;
+  unsigned getMemEncodingMMImm4sp(const MCInst &MI, unsigned OpNo,
+                                  SmallVectorImpl<MCFixup> &Fixups,
+                                  const MCSubtargetInfo &STI) const;
   unsigned getSizeExtEncoding(const MCInst &MI, unsigned OpNo,
                               SmallVectorImpl<MCFixup> &Fixups,
                               const MCSubtargetInfo &STI) const;
@@ -187,6 +190,10 @@ public:
   unsigned getRegisterListOpValue(const MCInst &MI, unsigned OpNo,
                                   SmallVectorImpl<MCFixup> &Fixups,
                                   const MCSubtargetInfo &STI) const;
+
+  unsigned getRegisterListOpValue16(const MCInst &MI, unsigned OpNo,
+                                    SmallVectorImpl<MCFixup> &Fixups,
+                                    const MCSubtargetInfo &STI) const;
 }; // class MipsMCCodeEmitter
 } // namespace llvm.
 
diff --git a/llvm/lib/Target/Mips/MicroMipsInstrFormats.td b/llvm/lib/Target/Mips/MicroMipsInstrFormats.td
index dcd0e597178..2301a1ccf8f 100644
--- a/llvm/lib/Target/Mips/MicroMipsInstrFormats.td
+++ b/llvm/lib/Target/Mips/MicroMipsInstrFormats.td
@@ -838,3 +838,15 @@ class LWM_FM_MM<bits<4> funct> : MMArch {
   let Inst{15-12} = funct;
   let Inst{11-0}  = addr{11-0};
 }
+
+class LWM_FM_MM16<bits<4> funct> : MMArch {
+  bits<2> rt;
+  bits<4> addr;
+
+  bits<16> Inst;
+
+  let Inst{15-10} = 0x11;
+  let Inst{9-6}   = funct;
+  let Inst{5-4}   = rt;
+  let Inst{3-0}   = addr;
+}
diff --git a/llvm/lib/Target/Mips/MicroMipsInstrInfo.td b/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
index bfd05303d1d..7180fb449aa 100644
--- a/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
+++ b/llvm/lib/Target/Mips/MicroMipsInstrInfo.td
@@ -86,6 +86,22 @@ def mem_mm_12 : Operand<i32> {
   let OperandType = "OPERAND_MEMORY";
 }
 
+def MipsMemUimm4AsmOperand : AsmOperandClass {
+  let Name = "MemOffsetUimm4";
+  let SuperClasses = [MipsMemAsmOperand];
+  let RenderMethod = "addMemOperands";
+  let ParserMethod = "parseMemOperand";
+  let PredicateMethod = "isMemWithUimmOffsetSP<6>";
+}
+
+def mem_mm_4sp : Operand<i32> {
+  let PrintMethod = "printMemOperand";
+  let MIOperandInfo = (ops GPR32, uimm8);
+  let EncoderMethod = "getMemEncodingMMImm4sp";
+  let ParserMatchClass = MipsMemUimm4AsmOperand;
+  let OperandType = "OPERAND_MEMORY";
+}
+
 def jmptarget_mm : Operand<OtherVT> {
   let EncoderMethod = "getJumpTargetOpValueMM";
 }
@@ -339,6 +355,20 @@ def reglist : Operand<i32> {
   let DecoderMethod = "DecodeRegListOperand";
 }
 
+def RegList16AsmOperand : AsmOperandClass {
+  let Name = "RegList16";
+  let ParserMethod = "parseRegisterList";
+  let PredicateMethod = "isRegList16";
+  let RenderMethod = "addRegListOperands";
+}
+
+def reglist16 : Operand<i32> {
+  let EncoderMethod = "getRegisterListOpValue16";
+  let DecoderMethod = "DecodeRegListOperand16";
+  let PrintMethod = "printRegisterList";
+  let ParserMatchClass = RegList16AsmOperand;
+}
+
 class StoreMultMM<string opstr,
             InstrItinClass Itin = NoItinerary, ComplexPattern Addr = addr> :
   InstSE<(outs), (ins reglist:$rt, mem_mm_12:$addr),
@@ -355,6 +385,22 @@ class LoadMultMM<string opstr,
   let mayLoad = 1;
 }
 
+class StoreMultMM16<string opstr,
+                    InstrItinClass Itin = NoItinerary,
+                    ComplexPattern Addr = addr> :
+  MicroMipsInst16<(outs), (ins reglist16:$rt, mem_mm_4sp:$addr),
+                  !strconcat(opstr, "\t$rt, $addr"), [], Itin, FrmI> {
+  let mayStore = 1;
+}
+
+class LoadMultMM16<string opstr,
+                   InstrItinClass Itin = NoItinerary,
+                   ComplexPattern Addr = addr> :
+  MicroMipsInst16<(outs reglist16:$rt), (ins mem_mm_4sp:$addr),
+                  !strconcat(opstr, "\t$rt, $addr"), [], Itin, FrmI> {
+  let mayLoad = 1;
+}
+
 def ADDU16_MM : ArithRMM16<"addu16", GPRMM16Opnd, 1, II_ADDU, add>,
                 ARITH_FM_MM16<0>;
 def SUBU16_MM : ArithRMM16<"subu16", GPRMM16Opnd, 0, II_SUBU, sub>,
@@ -504,6 +550,8 @@ let DecoderNamespace = "MicroMips", Predicates = [InMicroMips] in {
   /// Load and Store Instructions - multiple
   def SWM32_MM  : StoreMultMM<"swm32">, LWM_FM_MM<0xd>;
   def LWM32_MM  : LoadMultMM<"lwm32">, LWM_FM_MM<0x5>;
+  def SWM16_MM : StoreMultMM16<"swm16">, LWM_FM_MM16<0x5>;
+  def LWM16_MM : LoadMultMM16<"lwm16">, LWM_FM_MM16<0x4>;
 
   /// Move Conditional
   def MOVZ_I_MM : MMRel, CMov_I_I_FT<"movz", GPR32Opnd, GPR32Opnd,