MIPS: Refactor simulator and add selection instructions for r6.

src/mips64/disasm-mips64.cc

Index: src/mips64/disasm-mips64.cc
diff --git a/src/mips64/disasm-mips64.cc b/src/mips64/disasm-mips64.cc
index 3f0642db2c02d691fcd5fcba8d8b96c50410e62e..fc83955fe350ded4f5dbf8b95bc90aaee6411cc5 100644
--- a/src/mips64/disasm-mips64.cc
+++ b/src/mips64/disasm-mips64.cc
@@ -101,8 +101,23 @@ class Decoder {
   int DecodeBreakInstr(Instruction* instr);
 
   // Each of these functions decodes one particular instruction type.
+  void DecodeTypeRegisterDRsType(Instruction* instr);
+  void DecodeTypeRegisterLRsType(Instruction* instr);
+  void DecodeTypeRegisterSPECIAL(Instruction* instr);
+  void DecodeTypeRegisterSPECIAL2(Instruction* instr);
+  void DecodeTypeRegisterSPECIAL3(Instruction* instr);
+  void DecodeTypeRegisterCOP1(Instruction* instr);
+  void DecodeTypeRegisterCOP1X(Instruction* instr);
   int DecodeTypeRegister(Instruction* instr);
+
+  void DecodeTypeImmediateCOP1W(Instruction* instr);
+  void DecodeTypeImmediateCOP1L(Instruction* instr);
+  void DecodeTypeImmediateCOP1S(Instruction* instr);
+  void DecodeTypeImmediateCOP1D(Instruction* instr);
+  void DecodeTypeImmediateCOP1(Instruction* instr);
+  void DecodeTypeImmediateREGIMM(Instruction* instr);
   void DecodeTypeImmediate(Instruction* instr);
+
   void DecodeTypeJump(Instruction* instr);
 
   const disasm::NameConverter& converter_;
@@ -474,503 +489,547 @@ int Decoder::DecodeBreakInstr(Instruction* instr) {
 }
 
 
-int Decoder::DecodeTypeRegister(Instruction* instr) {
-  switch (instr->OpcodeFieldRaw()) {
-    case COP1:    // Coprocessor instructions.
-      switch (instr->RsFieldRaw()) {
-        case MFC1:
-          Format(instr, "mfc1    'rt, 'fs");
-          break;
-        case DMFC1:
-          Format(instr, "dmfc1    'rt, 'fs");
-          break;
-        case MFHC1:
-          Format(instr, "mfhc1   'rt, 'fs");
-          break;
-        case MTC1:
-          Format(instr, "mtc1    'rt, 'fs");
-          break;
-        case DMTC1:
-          Format(instr, "dmtc1    'rt, 'fs");
-          break;
-        // These are called "fs" too, although they are not FPU registers.
-        case CTC1:
-          Format(instr, "ctc1    'rt, 'fs");
-          break;
-        case CFC1:
-          Format(instr, "cfc1    'rt, 'fs");
-          break;
-        case MTHC1:
-          Format(instr, "mthc1   'rt, 'fs");
-          break;
-        case D:
-          switch (instr->FunctionFieldRaw()) {
-            case ADD_D:
-              Format(instr, "add.d   'fd, 'fs, 'ft");
-              break;
-            case SUB_D:
-              Format(instr, "sub.d   'fd, 'fs, 'ft");
-              break;
-            case MUL_D:
-              Format(instr, "mul.d   'fd, 'fs, 'ft");
-              break;
-            case DIV_D:
-              Format(instr, "div.d   'fd, 'fs, 'ft");
-              break;
-            case ABS_D:
-              Format(instr, "abs.d   'fd, 'fs");
-              break;
-            case MOV_D:
-              Format(instr, "mov.d   'fd, 'fs");
-              break;
-            case NEG_D:
-              Format(instr, "neg.d   'fd, 'fs");
-              break;
-            case SQRT_D:
-              Format(instr, "sqrt.d  'fd, 'fs");
-              break;
-            case CVT_W_D:
-              Format(instr, "cvt.w.d 'fd, 'fs");
-              break;
-            case CVT_L_D:
-              Format(instr, "cvt.l.d 'fd, 'fs");
-              break;
-            case TRUNC_W_D:
-              Format(instr, "trunc.w.d 'fd, 'fs");
-              break;
-            case TRUNC_L_D:
-              Format(instr, "trunc.l.d 'fd, 'fs");
-              break;
-            case ROUND_W_D:
-              Format(instr, "round.w.d 'fd, 'fs");
-              break;
-            case ROUND_L_D:
-              Format(instr, "round.l.d 'fd, 'fs");
-              break;
-            case FLOOR_W_D:
-              Format(instr, "floor.w.d 'fd, 'fs");
-              break;
-            case FLOOR_L_D:
-              Format(instr, "floor.l.d 'fd, 'fs");
-              break;
-            case CEIL_W_D:
-              Format(instr, "ceil.w.d 'fd, 'fs");
-              break;
-            case CEIL_L_D:
-              Format(instr, "ceil.l.d 'fd, 'fs");
-              break;
-            case CVT_S_D:
-              Format(instr, "cvt.s.d 'fd, 'fs");
-              break;
-            case C_F_D:
-              Format(instr, "c.f.d   'fs, 'ft, 'Cc");
-              break;
-            case C_UN_D:
-              Format(instr, "c.un.d  'fs, 'ft, 'Cc");
-              break;
-            case C_EQ_D:
-              Format(instr, "c.eq.d  'fs, 'ft, 'Cc");
-              break;
-            case C_UEQ_D:
-              Format(instr, "c.ueq.d 'fs, 'ft, 'Cc");
-              break;
-            case C_OLT_D:
-              Format(instr, "c.olt.d 'fs, 'ft, 'Cc");
-              break;
-            case C_ULT_D:
-              Format(instr, "c.ult.d 'fs, 'ft, 'Cc");
-              break;
-            case C_OLE_D:
-              Format(instr, "c.ole.d 'fs, 'ft, 'Cc");
-              break;
-            case C_ULE_D:
-              Format(instr, "c.ule.d 'fs, 'ft, 'Cc");
-              break;
-            default:
-              Format(instr, "unknown.cop1.d");
-              break;
-          }
-          break;
-        case W:
-          switch (instr->FunctionFieldRaw()) {
-            case CVT_D_W:   // Convert word to double.
-              Format(instr, "cvt.d.w 'fd, 'fs");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        case L:
-          switch (instr->FunctionFieldRaw()) {
-            case CVT_D_L:
-              Format(instr, "cvt.d.l 'fd, 'fs");
-              break;
-            case CVT_S_L:
-              Format(instr, "cvt.s.l 'fd, 'fs");
-              break;
-            case CMP_UN:
-              Format(instr, "cmp.un.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_EQ:
-              Format(instr, "cmp.eq.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_UEQ:
-              Format(instr, "cmp.ueq.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_LT:
-              Format(instr, "cmp.lt.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_ULT:
-              Format(instr, "cmp.ult.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_LE:
-              Format(instr, "cmp.le.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_ULE:
-              Format(instr, "cmp.ule.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_OR:
-              Format(instr, "cmp.or.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_UNE:
-              Format(instr, "cmp.une.d  'fd,  'fs, 'ft");
-              break;
-            case CMP_NE:
-              Format(instr, "cmp.ne.d  'fd,  'fs, 'ft");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        default:
-          UNREACHABLE();
-      }
+void Decoder::DecodeTypeRegisterDRsType(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case SELEQZ_C:
+      Format(instr, "seleqz.D    'ft, 'fs, 'fd");
       break;
-    case COP1X:
+    case SELNEZ_C:
+      Format(instr, "selnez.D    'ft, 'fs, 'fd");
+      break;
+    case ADD_D:
+      Format(instr, "add.d   'fd, 'fs, 'ft");
+      break;
+    case SUB_D:
+      Format(instr, "sub.d   'fd, 'fs, 'ft");
+      break;
+    case MUL_D:
+      Format(instr, "mul.d   'fd, 'fs, 'ft");
+      break;
+    case DIV_D:
+      Format(instr, "div.d   'fd, 'fs, 'ft");
+      break;
+    case ABS_D:
+      Format(instr, "abs.d   'fd, 'fs");
+      break;
+    case MOV_D:
+      Format(instr, "mov.d   'fd, 'fs");
+      break;
+    case NEG_D:
+      Format(instr, "neg.d   'fd, 'fs");
+      break;
+    case SQRT_D:
+      Format(instr, "sqrt.d  'fd, 'fs");
+      break;
+    case CVT_W_D:
+      Format(instr, "cvt.w.d 'fd, 'fs");
+      break;
+    case CVT_L_D:
+      Format(instr, "cvt.l.d 'fd, 'fs");
+      break;
+    case TRUNC_W_D:
+      Format(instr, "trunc.w.d 'fd, 'fs");
+      break;
+    case TRUNC_L_D:
+      Format(instr, "trunc.l.d 'fd, 'fs");
+      break;
+    case ROUND_W_D:
+      Format(instr, "round.w.d 'fd, 'fs");
+      break;
+    case ROUND_L_D:
+      Format(instr, "round.l.d 'fd, 'fs");
+      break;
+    case FLOOR_W_D:
+      Format(instr, "floor.w.d 'fd, 'fs");
+      break;
+    case FLOOR_L_D:
+      Format(instr, "floor.l.d 'fd, 'fs");
+      break;
+    case CEIL_W_D:
+      Format(instr, "ceil.w.d 'fd, 'fs");
+      break;
+    case CEIL_L_D:
+      Format(instr, "ceil.l.d 'fd, 'fs");
+      break;
+    case CVT_S_D:
+      Format(instr, "cvt.s.d 'fd, 'fs");
+      break;
+    case C_F_D:
+      Format(instr, "c.f.d   'fs, 'ft, 'Cc");
+      break;
+    case C_UN_D:
+      Format(instr, "c.un.d  'fs, 'ft, 'Cc");
+      break;
+    case C_EQ_D:
+      Format(instr, "c.eq.d  'fs, 'ft, 'Cc");
+      break;
+    case C_UEQ_D:
+      Format(instr, "c.ueq.d 'fs, 'ft, 'Cc");
+      break;
+    case C_OLT_D:
+      Format(instr, "c.olt.d 'fs, 'ft, 'Cc");
+      break;
+    case C_ULT_D:
+      Format(instr, "c.ult.d 'fs, 'ft, 'Cc");
+      break;
+    case C_OLE_D:
+      Format(instr, "c.ole.d 'fs, 'ft, 'Cc");
+      break;
+    case C_ULE_D:
+      Format(instr, "c.ule.d 'fs, 'ft, 'Cc");
+      break;
+    default:
+      Format(instr, "unknown.cop1.d");
+      break;
+  }
+}
+
+
+void Decoder::DecodeTypeRegisterLRsType(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case CVT_D_L:
+      Format(instr, "cvt.d.l 'fd, 'fs");
+      break;
+    case CVT_S_L:
+      Format(instr, "cvt.s.l 'fd, 'fs");
+      break;
+    case CMP_UN:
+      Format(instr, "cmp.un.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_EQ:
+      Format(instr, "cmp.eq.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_UEQ:
+      Format(instr, "cmp.ueq.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_LT:
+      Format(instr, "cmp.lt.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_ULT:
+      Format(instr, "cmp.ult.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_LE:
+      Format(instr, "cmp.le.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_ULE:
+      Format(instr, "cmp.ule.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_OR:
+      Format(instr, "cmp.or.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_UNE:
+      Format(instr, "cmp.une.d  'fd,  'fs, 'ft");
+      break;
+    case CMP_NE:
+      Format(instr, "cmp.ne.d  'fd,  'fs, 'ft");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeRegisterCOP1(Instruction* instr) {
+  switch (instr->RsFieldRaw()) {
+    case MFC1:
+      Format(instr, "mfc1    'rt, 'fs");
+      break;
+    case DMFC1:
+      Format(instr, "dmfc1    'rt, 'fs");
+      break;
+    case MFHC1:
+      Format(instr, "mfhc1   'rt, 'fs");
+      break;
+    case MTC1:
+      Format(instr, "mtc1    'rt, 'fs");
+      break;
+    case DMTC1:
+      Format(instr, "dmtc1    'rt, 'fs");
+      break;
+    // These are called "fs" too, although they are not FPU registers.
+    case CTC1:
+      Format(instr, "ctc1    'rt, 'fs");
+      break;
+    case CFC1:
+      Format(instr, "cfc1    'rt, 'fs");
+      break;
+    case MTHC1:
+      Format(instr, "mthc1   'rt, 'fs");
+      break;
+    case D:
+      DecodeTypeRegisterDRsType(instr);
+      break;
+    case W:
       switch (instr->FunctionFieldRaw()) {
-        case MADD_D:
-          Format(instr, "madd.d  'fd, 'fr, 'fs, 'ft");
+        case CVT_D_W:  // Convert word to double.
+          Format(instr, "cvt.d.w 'fd, 'fs");
           break;
         default:
           UNREACHABLE();
       }
       break;
-    case SPECIAL:
-      switch (instr->FunctionFieldRaw()) {
-        case JR:
-          Format(instr, "jr      'rs");
-          break;
-        case JALR:
-          Format(instr, "jalr    'rs");
-          break;
-        case SLL:
-          if (0x0 == static_cast<int>(instr->InstructionBits()))
-            Format(instr, "nop");
-          else
-            Format(instr, "sll     'rd, 'rt, 'sa");
-          break;
-        case DSLL:
-            Format(instr, "dsll    'rd, 'rt, 'sa");
-          break;
-        case D_MUL_MUH:  // Equals to DMUL.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "dmult   'rs, 'rt");
-          } else {
-            if (instr->SaValue() == MUL_OP) {
-              Format(instr, "dmul   'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "dmuh   'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case DSLL32:
-          Format(instr, "dsll32  'rd, 'rt, 'sa");
-          break;
-        case SRL:
-          if (instr->RsValue() == 0) {
-            Format(instr, "srl     'rd, 'rt, 'sa");
-          } else {
-            if (kArchVariant == kMips64r2) {
-              Format(instr, "rotr    'rd, 'rt, 'sa");
-            } else {
-              Unknown(instr);
-            }
-          }
-          break;
-        case DSRL:
-          if (instr->RsValue() == 0) {
-            Format(instr, "dsrl    'rd, 'rt, 'sa");
-          } else {
-            if (kArchVariant == kMips64r2) {
-              Format(instr, "drotr   'rd, 'rt, 'sa");
-            } else {
-              Unknown(instr);
-            }
-          }
-          break;
-        case DSRL32:
-          Format(instr, "dsrl32  'rd, 'rt, 'sa");
-          break;
-        case SRA:
-          Format(instr, "sra     'rd, 'rt, 'sa");
-          break;
-        case DSRA:
-          Format(instr, "dsra    'rd, 'rt, 'sa");
-          break;
-        case DSRA32:
-          Format(instr, "dsra32  'rd, 'rt, 'sa");
-          break;
-        case SLLV:
-          Format(instr, "sllv    'rd, 'rt, 'rs");
-          break;
-        case DSLLV:
-          Format(instr, "dsllv   'rd, 'rt, 'rs");
-          break;
-        case SRLV:
-          if (instr->SaValue() == 0) {
-            Format(instr, "srlv    'rd, 'rt, 'rs");
-          } else {
-            if (kArchVariant == kMips64r2) {
-              Format(instr, "rotrv   'rd, 'rt, 'rs");
-            } else {
-              Unknown(instr);
-            }
-          }
-          break;
-        case DSRLV:
-          if (instr->SaValue() == 0) {
-            Format(instr, "dsrlv   'rd, 'rt, 'rs");
-          } else {
-            if (kArchVariant == kMips64r2) {
-              Format(instr, "drotrv  'rd, 'rt, 'rs");
-            } else {
-              Unknown(instr);
-            }
-          }
-          break;
-        case SRAV:
-          Format(instr, "srav    'rd, 'rt, 'rs");
-          break;
-        case DSRAV:
-          Format(instr, "dsrav   'rd, 'rt, 'rs");
-          break;
-        case MFHI:
-          if (instr->Bits(25, 16) == 0) {
-            Format(instr, "mfhi    'rd");
-          } else {
-            if ((instr->FunctionFieldRaw() == CLZ_R6)
-                && (instr->FdValue() == 1)) {
-              Format(instr, "clz     'rd, 'rs");
-            } else if ((instr->FunctionFieldRaw() == CLO_R6)
-                && (instr->FdValue() == 1)) {
-              Format(instr, "clo     'rd, 'rs");
-            }
-          }
-          break;
-        case MFLO:
-          Format(instr, "mflo    'rd");
-          break;
-        case D_MUL_MUH_U:  // Equals to DMULTU.
-          if (kArchVariant != kMips64r6) {
-              Format(instr, "dmultu  'rs, 'rt");
-          } else {
-            if (instr->SaValue() == MUL_OP) {
-              Format(instr, "dmulu  'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "dmuhu  'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case MULT:  // @Mips64r6 == MUL_MUH.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "mult    'rs, 'rt");
-          } else {
-            if (instr->SaValue() == MUL_OP) {
-              Format(instr, "mul    'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "muh    'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case MULTU:  // @Mips64r6 == MUL_MUH_U.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "multu   'rs, 'rt");
-          } else {
-            if (instr->SaValue() == MUL_OP) {
-              Format(instr, "mulu   'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "muhu   'rd, 'rs, 'rt");
-            }
-          }
+    case L:
+      DecodeTypeRegisterLRsType(instr);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
 
-          break;
-        case DIV:  // @Mips64r6 == DIV_MOD.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "div     'rs, 'rt");
-          } else {
-            if (instr->SaValue() == DIV_OP) {
-              Format(instr, "div    'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "mod    'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case DDIV:  // @Mips64r6 == D_DIV_MOD.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "ddiv    'rs, 'rt");
-          } else {
-            if (instr->SaValue() == DIV_OP) {
-              Format(instr, "ddiv   'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "dmod   'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case DIVU:  // @Mips64r6 == DIV_MOD_U.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "divu    'rs, 'rt");
-          } else {
-            if (instr->SaValue() == DIV_OP) {
-              Format(instr, "divu   'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "modu   'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case DDIVU:  // @Mips64r6 == D_DIV_MOD_U.
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "ddivu   'rs, 'rt");
-          } else {
-            if (instr->SaValue() == DIV_OP) {
-              Format(instr, "ddivu  'rd, 'rs, 'rt");
-            } else {
-              Format(instr, "dmodu  'rd, 'rs, 'rt");
-            }
-          }
-          break;
-        case ADD:
-          Format(instr, "add     'rd, 'rs, 'rt");
-          break;
-        case DADD:
-          Format(instr, "dadd    'rd, 'rs, 'rt");
-          break;
-        case ADDU:
-          Format(instr, "addu    'rd, 'rs, 'rt");
-          break;
-        case DADDU:
-          Format(instr, "daddu   'rd, 'rs, 'rt");
-          break;
-        case SUB:
-          Format(instr, "sub     'rd, 'rs, 'rt");
-          break;
-        case DSUB:
-          Format(instr, "dsub    'rd, 'rs, 'rt");
-          break;
-        case SUBU:
-          Format(instr, "subu    'rd, 'rs, 'rt");
-          break;
-        case DSUBU:
-          Format(instr, "dsubu   'rd, 'rs, 'rt");
-          break;
-        case AND:
-          Format(instr, "and     'rd, 'rs, 'rt");
-          break;
-        case OR:
-          if (0 == instr->RsValue()) {
-            Format(instr, "mov     'rd, 'rt");
-          } else if (0 == instr->RtValue()) {
-            Format(instr, "mov     'rd, 'rs");
-          } else {
-            Format(instr, "or      'rd, 'rs, 'rt");
-          }
-          break;
-        case XOR:
-          Format(instr, "xor     'rd, 'rs, 'rt");
-          break;
-        case NOR:
-          Format(instr, "nor     'rd, 'rs, 'rt");
-          break;
-        case SLT:
-          Format(instr, "slt     'rd, 'rs, 'rt");
-          break;
-        case SLTU:
-          Format(instr, "sltu    'rd, 'rs, 'rt");
-          break;
-        case BREAK:
-          return DecodeBreakInstr(instr);
-        case TGE:
-          Format(instr, "tge     'rs, 'rt, code: 'code");
-          break;
-        case TGEU:
-          Format(instr, "tgeu    'rs, 'rt, code: 'code");
-          break;
-        case TLT:
-          Format(instr, "tlt     'rs, 'rt, code: 'code");
-          break;
-        case TLTU:
-          Format(instr, "tltu    'rs, 'rt, code: 'code");
-          break;
-        case TEQ:
-          Format(instr, "teq     'rs, 'rt, code: 'code");
-          break;
-        case TNE:
-          Format(instr, "tne     'rs, 'rt, code: 'code");
-          break;
-        case MOVZ:
-          Format(instr, "movz    'rd, 'rs, 'rt");
-          break;
-        case MOVN:
-          Format(instr, "movn    'rd, 'rs, 'rt");
-          break;
-        case MOVCI:
-          if (instr->Bit(16)) {
-            Format(instr, "movt    'rd, 'rs, 'bc");
-          } else {
-            Format(instr, "movf    'rd, 'rs, 'bc");
-          }
-          break;
-        case SELEQZ_S:
-          Format(instr, "seleqz    'rd, 'rs, 'rt");
-          break;
-        case SELNEZ_S:
-          Format(instr, "selnez    'rd, 'rs, 'rt");
-          break;
-        default:
-          UNREACHABLE();
+
+void Decoder::DecodeTypeRegisterCOP1X(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case MADD_D:
+      Format(instr, "madd.d  'fd, 'fr, 'fs, 'ft");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeRegisterSPECIAL(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case JR:
+      Format(instr, "jr      'rs");
+      break;
+    case JALR:
+      Format(instr, "jalr    'rs");
+      break;
+    case SLL:
+      if (0x0 == static_cast<int>(instr->InstructionBits()))
+        Format(instr, "nop");
+      else
+        Format(instr, "sll     'rd, 'rt, 'sa");
+      break;
+    case DSLL:
+      Format(instr, "dsll    'rd, 'rt, 'sa");
+      break;
+    case D_MUL_MUH:  // Equals to DMUL.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "dmult   'rs, 'rt");
+      } else {
+        if (instr->SaValue() == MUL_OP) {
+          Format(instr, "dmul   'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "dmuh   'rd, 'rs, 'rt");
+        }
       }
       break;
-    case SPECIAL2:
-      switch (instr->FunctionFieldRaw()) {
-        case MUL:
-          Format(instr, "mul     'rd, 'rs, 'rt");
-          break;
-        case CLZ:
-          if (kArchVariant != kMips64r6) {
-            Format(instr, "clz     'rd, 'rs");
-          }
-          break;
-        default:
-          UNREACHABLE();
+    case DSLL32:
+      Format(instr, "dsll32  'rd, 'rt, 'sa");
+      break;
+    case SRL:
+      if (instr->RsValue() == 0) {
+        Format(instr, "srl     'rd, 'rt, 'sa");
+      } else {
+        if (kArchVariant == kMips64r2) {
+          Format(instr, "rotr    'rd, 'rt, 'sa");
+        } else {
+          Unknown(instr);
+        }
       }
       break;
-    case SPECIAL3:
-      switch (instr->FunctionFieldRaw()) {
-        case INS: {
-          Format(instr, "ins     'rt, 'rs, 'sa, 'ss2");
-          break;
+    case DSRL:
+      if (instr->RsValue() == 0) {
+        Format(instr, "dsrl    'rd, 'rt, 'sa");
+      } else {
+        if (kArchVariant == kMips64r2) {
+          Format(instr, "drotr   'rd, 'rt, 'sa");
+        } else {
+          Unknown(instr);
         }
-        case EXT: {
-          Format(instr, "ext     'rt, 'rs, 'sa, 'ss1");
-          break;
+      }
+      break;
+    case DSRL32:
+      Format(instr, "dsrl32  'rd, 'rt, 'sa");
+      break;
+    case SRA:
+      Format(instr, "sra     'rd, 'rt, 'sa");
+      break;
+    case DSRA:
+      Format(instr, "dsra    'rd, 'rt, 'sa");
+      break;
+    case DSRA32:
+      Format(instr, "dsra32  'rd, 'rt, 'sa");
+      break;
+    case SLLV:
+      Format(instr, "sllv    'rd, 'rt, 'rs");
+      break;
+    case DSLLV:
+      Format(instr, "dsllv   'rd, 'rt, 'rs");
+      break;
+    case SRLV:
+      if (instr->SaValue() == 0) {
+        Format(instr, "srlv    'rd, 'rt, 'rs");
+      } else {
+        if (kArchVariant == kMips64r2) {
+          Format(instr, "rotrv   'rd, 'rt, 'rs");
+        } else {
+          Unknown(instr);
         }
-        case DEXT: {
-          Format(instr, "dext    'rt, 'rs, 'sa, 'ss1");
-          break;
+      }
+      break;
+    case DSRLV:
+      if (instr->SaValue() == 0) {
+        Format(instr, "dsrlv   'rd, 'rt, 'rs");
+      } else {
+        if (kArchVariant == kMips64r2) {
+          Format(instr, "drotrv  'rd, 'rt, 'rs");
+        } else {
+          Unknown(instr);
+        }
+      }
+      break;
+    case SRAV:
+      Format(instr, "srav    'rd, 'rt, 'rs");
+      break;
+    case DSRAV:
+      Format(instr, "dsrav   'rd, 'rt, 'rs");
+      break;
+    case MFHI:
+      if (instr->Bits(25, 16) == 0) {
+        Format(instr, "mfhi    'rd");
+      } else {
+        if ((instr->FunctionFieldRaw() == CLZ_R6) && (instr->FdValue() == 1)) {
+          Format(instr, "clz     'rd, 'rs");
+        } else if ((instr->FunctionFieldRaw() == CLO_R6) &&
+                   (instr->FdValue() == 1)) {
+          Format(instr, "clo     'rd, 'rs");
         }
+      }
+      break;
+    case MFLO:
+      Format(instr, "mflo    'rd");
+      break;
+    case D_MUL_MUH_U:  // Equals to DMULTU.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "dmultu  'rs, 'rt");
+      } else {
+        if (instr->SaValue() == MUL_OP) {
+          Format(instr, "dmulu  'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "dmuhu  'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case MULT:  // @Mips64r6 == MUL_MUH.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "mult    'rs, 'rt");
+      } else {
+        if (instr->SaValue() == MUL_OP) {
+          Format(instr, "mul    'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "muh    'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case MULTU:  // @Mips64r6 == MUL_MUH_U.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "multu   'rs, 'rt");
+      } else {
+        if (instr->SaValue() == MUL_OP) {
+          Format(instr, "mulu   'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "muhu   'rd, 'rs, 'rt");
+        }
+      }
+
+      break;
+    case DIV:  // @Mips64r6 == DIV_MOD.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "div     'rs, 'rt");
+      } else {
+        if (instr->SaValue() == DIV_OP) {
+          Format(instr, "div    'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "mod    'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case DDIV:  // @Mips64r6 == D_DIV_MOD.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "ddiv    'rs, 'rt");
+      } else {
+        if (instr->SaValue() == DIV_OP) {
+          Format(instr, "ddiv   'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "dmod   'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case DIVU:  // @Mips64r6 == DIV_MOD_U.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "divu    'rs, 'rt");
+      } else {
+        if (instr->SaValue() == DIV_OP) {
+          Format(instr, "divu   'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "modu   'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case DDIVU:  // @Mips64r6 == D_DIV_MOD_U.
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "ddivu   'rs, 'rt");
+      } else {
+        if (instr->SaValue() == DIV_OP) {
+          Format(instr, "ddivu  'rd, 'rs, 'rt");
+        } else {
+          Format(instr, "dmodu  'rd, 'rs, 'rt");
+        }
+      }
+      break;
+    case ADD:
+      Format(instr, "add     'rd, 'rs, 'rt");
+      break;
+    case DADD:
+      Format(instr, "dadd    'rd, 'rs, 'rt");
+      break;
+    case ADDU:
+      Format(instr, "addu    'rd, 'rs, 'rt");
+      break;
+    case DADDU:
+      Format(instr, "daddu   'rd, 'rs, 'rt");
+      break;
+    case SUB:
+      Format(instr, "sub     'rd, 'rs, 'rt");
+      break;
+    case DSUB:
+      Format(instr, "dsub    'rd, 'rs, 'rt");
+      break;
+    case SUBU:
+      Format(instr, "subu    'rd, 'rs, 'rt");
+      break;
+    case DSUBU:
+      Format(instr, "dsubu   'rd, 'rs, 'rt");
+      break;
+    case AND:
+      Format(instr, "and     'rd, 'rs, 'rt");
+      break;
+    case OR:
+      if (0 == instr->RsValue()) {
+        Format(instr, "mov     'rd, 'rt");
+      } else if (0 == instr->RtValue()) {
+        Format(instr, "mov     'rd, 'rs");
+      } else {
+        Format(instr, "or      'rd, 'rs, 'rt");
+      }
+      break;
+    case XOR:
+      Format(instr, "xor     'rd, 'rs, 'rt");
+      break;
+    case NOR:
+      Format(instr, "nor     'rd, 'rs, 'rt");
+      break;
+    case SLT:
+      Format(instr, "slt     'rd, 'rs, 'rt");
+      break;
+    case SLTU:
+      Format(instr, "sltu    'rd, 'rs, 'rt");
+      break;
+    case TGE:
+      Format(instr, "tge     'rs, 'rt, code: 'code");
+      break;
+    case TGEU:
+      Format(instr, "tgeu    'rs, 'rt, code: 'code");
+      break;
+    case TLT:
+      Format(instr, "tlt     'rs, 'rt, code: 'code");
+      break;
+    case TLTU:
+      Format(instr, "tltu    'rs, 'rt, code: 'code");
+      break;
+    case TEQ:
+      Format(instr, "teq     'rs, 'rt, code: 'code");
+      break;
+    case TNE:
+      Format(instr, "tne     'rs, 'rt, code: 'code");
+      break;
+    case MOVZ:
+      Format(instr, "movz    'rd, 'rs, 'rt");
+      break;
+    case MOVN:
+      Format(instr, "movn    'rd, 'rs, 'rt");
+      break;
+    case MOVCI:
+      if (instr->Bit(16)) {
+        Format(instr, "movt    'rd, 'rs, 'bc");
+      } else {
+        Format(instr, "movf    'rd, 'rs, 'bc");
+      }
+      break;
+    case SELEQZ_S:
+      Format(instr, "seleqz    'rs, 'rt, 'rd");
+      break;
+    case SELNEZ_S:
+      Format(instr, "selnez    'rs, 'rt, 'rd");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeRegisterSPECIAL2(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case MUL:
+      Format(instr, "mul     'rd, 'rs, 'rt");
+      break;
+    case CLZ:
+      if (kArchVariant != kMips64r6) {
+        Format(instr, "clz     'rd, 'rs");
+      }
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeRegisterSPECIAL3(Instruction* instr) {
+  switch (instr->FunctionFieldRaw()) {
+    case INS: {
+      Format(instr, "ins     'rt, 'rs, 'sa, 'ss2");
+      break;
+    }
+    case EXT: {
+      Format(instr, "ext     'rt, 'rs, 'sa, 'ss1");
+      break;
+    }
+    case DEXT: {
+      Format(instr, "dext    'rt, 'rs, 'sa, 'ss1");
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+int Decoder::DecodeTypeRegister(Instruction* instr) {
+  switch (instr->OpcodeFieldRaw()) {
+    case COP1:  // Coprocessor instructions.
+      DecodeTypeRegisterCOP1(instr);
+      break;
+    case COP1X:
+      DecodeTypeRegisterCOP1X(instr);
+      break;
+    case SPECIAL:
+      switch (instr->FunctionFieldRaw()) {
+        case BREAK:
+          return DecodeBreakInstr(instr);
         default:
-          UNREACHABLE();
+          DecodeTypeRegisterSPECIAL(instr);
+          break;
       }
       break;
+    case SPECIAL2:
+      DecodeTypeRegisterSPECIAL2(instr);
+      break;
+    case SPECIAL3:
+      DecodeTypeRegisterSPECIAL3(instr);
+      break;
     default:
       UNREACHABLE();
   }
@@ -978,187 +1037,216 @@ int Decoder::DecodeTypeRegister(Instruction* instr) {
 }
 
 
+void Decoder::DecodeTypeImmediateCOP1D(Instruction* instr) {
+  switch (instr->FunctionValue()) {
+    case SEL:
+      Format(instr, "sel.D    'ft, 'fs, 'fd");
+      break;
+    case SELEQZ_C:
+      Format(instr, "seleqz.D 'ft, 'fs, 'fd");
+      break;
+    case SELNEZ_C:
+      Format(instr, "selnez.D 'ft, 'fs, 'fd");
+      break;
+    case MIN:
+      Format(instr, "min.D    'ft, 'fs, 'fd");
+      break;
+    case MINA:
+      Format(instr, "mina.D   'ft, 'fs, 'fd");
+      break;
+    case MAX:
+      Format(instr, "max.D    'ft, 'fs, 'fd");
+      break;
+    case MAXA:
+      Format(instr, "maxa.D   'ft, 'fs, 'fd");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeImmediateCOP1L(Instruction* instr) {
+  switch (instr->FunctionValue()) {
+    case CMP_AF:
+      Format(instr, "cmp.af.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_UN:
+      Format(instr, "cmp.un.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_EQ:
+      Format(instr, "cmp.eq.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_UEQ:
+      Format(instr, "cmp.ueq.D   'ft, 'fs, 'fd");
+      break;
+    case CMP_LT:
+      Format(instr, "cmp.lt.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_ULT:
+      Format(instr, "cmp.ult.D   'ft, 'fs, 'fd");
+      break;
+    case CMP_LE:
+      Format(instr, "cmp.le.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_ULE:
+      Format(instr, "cmp.ule.D   'ft, 'fs, 'fd");
+      break;
+    case CMP_OR:
+      Format(instr, "cmp.or.D    'ft, 'fs, 'fd");
+      break;
+    case CMP_UNE:
+      Format(instr, "cmp.une.D   'ft, 'fs, 'fd");
+      break;
+    case CMP_NE:
+      Format(instr, "cmp.ne.D    'ft, 'fs, 'fd");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeImmediateCOP1S(Instruction* instr) {
+  switch (instr->FunctionValue()) {
+    case SEL:
+      Format(instr, "sel.S    'ft, 'fs, 'fd");
+      break;
+    case SELEQZ_C:
+      Format(instr, "seleqz.S 'ft, 'fs, 'fd");
+      break;
+    case SELNEZ_C:
+      Format(instr, "selnez.S 'ft, 'fs, 'fd");
+      break;
+    case MIN:
+      Format(instr, "min.S    'ft, 'fs, 'fd");
+      break;
+    case MINA:
+      Format(instr, "mina.S   'ft, 'fs, 'fd");
+      break;
+    case MAX:
+      Format(instr, "max.S    'ft, 'fs, 'fd");
+      break;
+    case MAXA:
+      Format(instr, "maxa.S   'ft, 'fs, 'fd");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeImmediateCOP1W(Instruction* instr) {
+  switch (instr->FunctionValue()) {
+    case CMP_AF:
+      Format(instr, "cmp.af.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_UN:
+      Format(instr, "cmp.un.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_EQ:
+      Format(instr, "cmp.eq.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_UEQ:
+      Format(instr, "cmp.ueq.S   'ft, 'fs, 'fd");
+      break;
+    case CMP_LT:
+      Format(instr, "cmp.lt.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_ULT:
+      Format(instr, "cmp.ult.S   'ft, 'fs, 'fd");
+      break;
+    case CMP_LE:
+      Format(instr, "cmp.le.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_ULE:
+      Format(instr, "cmp.ule.S   'ft, 'fs, 'fd");
+      break;
+    case CMP_OR:
+      Format(instr, "cmp.or.S    'ft, 'fs, 'fd");
+      break;
+    case CMP_UNE:
+      Format(instr, "cmp.une.S   'ft, 'fs, 'fd");
+      break;
+    case CMP_NE:
+      Format(instr, "cmp.ne.S    'ft, 'fs, 'fd");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeImmediateCOP1(Instruction* instr) {
+  switch (instr->RsFieldRaw()) {
+    case BC1:
+      if (instr->FBtrueValue()) {
+        Format(instr, "bc1t    'bc, 'imm16u");
+      } else {
+        Format(instr, "bc1f    'bc, 'imm16u");
+      }
+      break;
+    case BC1EQZ:
+      Format(instr, "bc1eqz    'ft, 'imm16u");
+      break;
+    case BC1NEZ:
+      Format(instr, "bc1nez    'ft, 'imm16u");
+      break;
+    case W:  // CMP.S instruction.
+      DecodeTypeImmediateCOP1W(instr);
+      break;
+    case L:  // CMP.D instruction.
+      DecodeTypeImmediateCOP1L(instr);
+      break;
+    case S:
+      DecodeTypeImmediateCOP1S(instr);
+      break;
+    case D:
+      DecodeTypeImmediateCOP1D(instr);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Decoder::DecodeTypeImmediateREGIMM(Instruction* instr) {
+  switch (instr->RtFieldRaw()) {
+    case BLTZ:
+      Format(instr, "bltz    'rs, 'imm16u");
+      break;
+    case BLTZAL:
+      Format(instr, "bltzal  'rs, 'imm16u");
+      break;
+    case BGEZ:
+      Format(instr, "bgez    'rs, 'imm16u");
+      break;
+    case BGEZAL:
+      Format(instr, "bgezal  'rs, 'imm16u");
+      break;
+    case BGEZALL:
+      Format(instr, "bgezall 'rs, 'imm16u");
+      break;
+    case DAHI:
+      Format(instr, "dahi    'rs, 'imm16u");
+      break;
+    case DATI:
+      Format(instr, "dati    'rs, 'imm16u");
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
 void Decoder::DecodeTypeImmediate(Instruction* instr) {
   switch (instr->OpcodeFieldRaw()) {
     case COP1:
-      switch (instr->RsFieldRaw()) {
-        case BC1:
-          if (instr->FBtrueValue()) {
-            Format(instr, "bc1t    'bc, 'imm16u");
-          } else {
-            Format(instr, "bc1f    'bc, 'imm16u");
-          }
-          break;
-        case BC1EQZ:
-          Format(instr, "bc1eqz    'ft, 'imm16u");
-          break;
-        case BC1NEZ:
-          Format(instr, "bc1nez    'ft, 'imm16u");
-          break;
-        case W:  // CMP.S instruction.
-          switch (instr->FunctionValue()) {
-            case CMP_AF:
-              Format(instr, "cmp.af.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_UN:
-              Format(instr, "cmp.un.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_EQ:
-              Format(instr, "cmp.eq.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_UEQ:
-              Format(instr, "cmp.ueq.S   'ft, 'fs, 'fd");
-              break;
-            case CMP_LT:
-              Format(instr, "cmp.lt.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_ULT:
-              Format(instr, "cmp.ult.S   'ft, 'fs, 'fd");
-              break;
-            case CMP_LE:
-              Format(instr, "cmp.le.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_ULE:
-              Format(instr, "cmp.ule.S   'ft, 'fs, 'fd");
-              break;
-            case CMP_OR:
-              Format(instr, "cmp.or.S    'ft, 'fs, 'fd");
-              break;
-            case CMP_UNE:
-              Format(instr, "cmp.une.S   'ft, 'fs, 'fd");
-              break;
-            case CMP_NE:
-              Format(instr, "cmp.ne.S    'ft, 'fs, 'fd");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        case L:  // CMP.D instruction.
-          switch (instr->FunctionValue()) {
-            case CMP_AF:
-              Format(instr, "cmp.af.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_UN:
-              Format(instr, "cmp.un.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_EQ:
-              Format(instr, "cmp.eq.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_UEQ:
-              Format(instr, "cmp.ueq.D   'ft, 'fs, 'fd");
-              break;
-            case CMP_LT:
-              Format(instr, "cmp.lt.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_ULT:
-              Format(instr, "cmp.ult.D   'ft, 'fs, 'fd");
-              break;
-            case CMP_LE:
-              Format(instr, "cmp.le.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_ULE:
-              Format(instr, "cmp.ule.D   'ft, 'fs, 'fd");
-              break;
-            case CMP_OR:
-              Format(instr, "cmp.or.D    'ft, 'fs, 'fd");
-              break;
-            case CMP_UNE:
-              Format(instr, "cmp.une.D   'ft, 'fs, 'fd");
-              break;
-            case CMP_NE:
-              Format(instr, "cmp.ne.D    'ft, 'fs, 'fd");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        case S:
-          switch (instr->FunctionValue()) {
-            case SEL:
-              Format(instr, "sel.S    'ft, 'fs, 'fd");
-              break;
-            case SELEQZ_C:
-              Format(instr, "seleqz.S 'ft, 'fs, 'fd");
-              break;
-            case SELNEZ_C:
-              Format(instr, "selnez.S 'ft, 'fs, 'fd");
-              break;
-            case MIN:
-              Format(instr, "min.S    'ft, 'fs, 'fd");
-              break;
-            case MINA:
-              Format(instr, "mina.S   'ft, 'fs, 'fd");
-              break;
-            case MAX:
-              Format(instr, "max.S    'ft, 'fs, 'fd");
-              break;
-            case MAXA:
-              Format(instr, "maxa.S   'ft, 'fs, 'fd");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        case D:
-          switch (instr->FunctionValue()) {
-            case SEL:
-              Format(instr, "sel.D    'ft, 'fs, 'fd");
-              break;
-            case SELEQZ_C:
-              Format(instr, "seleqz.D 'ft, 'fs, 'fd");
-              break;
-            case SELNEZ_C:
-              Format(instr, "selnez.D 'ft, 'fs, 'fd");
-              break;
-            case MIN:
-              Format(instr, "min.D    'ft, 'fs, 'fd");
-              break;
-            case MINA:
-              Format(instr, "mina.D   'ft, 'fs, 'fd");
-              break;
-            case MAX:
-              Format(instr, "max.D    'ft, 'fs, 'fd");
-              break;
-            case MAXA:
-              Format(instr, "maxa.D   'ft, 'fs, 'fd");
-              break;
-            default:
-              UNREACHABLE();
-          }
-          break;
-        default:
-          UNREACHABLE();
-      }
-
+      DecodeTypeImmediateCOP1(instr);
       break;  // Case COP1.
     // ------------- REGIMM class.
     case REGIMM:
-      switch (instr->RtFieldRaw()) {
-        case BLTZ:
-          Format(instr, "bltz    'rs, 'imm16u");
-          break;
-        case BLTZAL:
-          Format(instr, "bltzal  'rs, 'imm16u");
-          break;
-        case BGEZ:
-          Format(instr, "bgez    'rs, 'imm16u");
-          break;
-        case BGEZAL:
-          Format(instr, "bgezal  'rs, 'imm16u");
-          break;
-        case BGEZALL:
-          Format(instr, "bgezall 'rs, 'imm16u");
-          break;
-        case DAHI:
-          Format(instr, "dahi    'rs, 'imm16u");
-          break;
-        case DATI:
-          Format(instr, "dati    'rs, 'imm16u");
-          break;
-        default:
-          UNREACHABLE();
-      }
+
     break;  // Case REGIMM.
     // ------------- Branch instructions.
     case BEQ: