1  using ARMeilleure.Decoders;
  2  using ARMeilleure.IntermediateRepresentation;
  3  using ARMeilleure.State;
  4  using ARMeilleure.Translation;
  5  using System;
  6  
  7  using static ARMeilleure.IntermediateRepresentation.Operand.Factory;
  8  
  9  namespace ARMeilleure.Instructions
 10  {
 11      static class InstEmitHelper
 12      {
 13          public static Operand GetExtendedM(ArmEmitterContext context, int rm, IntType type)
 14          {
 15              Operand value = GetIntOrZR(context, rm);
 16  
 17              switch (type)
 18              {
 19                  case IntType.UInt8:
 20                      value = context.ZeroExtend8(value.Type, value);
 21                      break;
 22                  case IntType.UInt16:
 23                      value = context.ZeroExtend16(value.Type, value);
 24                      break;
 25                  case IntType.UInt32:
 26                      value = context.ZeroExtend32(value.Type, value);
 27                      break;
 28  
 29                  case IntType.Int8:
 30                      value = context.SignExtend8(value.Type, value);
 31                      break;
 32                  case IntType.Int16:
 33                      value = context.SignExtend16(value.Type, value);
 34                      break;
 35                  case IntType.Int32:
 36                      value = context.SignExtend32(value.Type, value);
 37                      break;
 38              }
 39  
 40              return value;
 41          }
 42  
 43          public static Operand GetIntA32(ArmEmitterContext context, int regIndex)
 44          {
 45              if (regIndex == RegisterAlias.Aarch32Pc)
 46              {
 47                  OpCode32 op = (OpCode32)context.CurrOp;
 48  
 49                  return Const((int)op.GetPc());
 50              }
 51              else
 52              {
 53                  return Register(GetRegisterAlias(context.Mode, regIndex), RegisterType.Integer, OperandType.I32);
 54              }
 55          }
 56  
 57          public static Operand GetIntA32AlignedPC(ArmEmitterContext context, int regIndex)
 58          {
 59              if (regIndex == RegisterAlias.Aarch32Pc)
 60              {
 61                  OpCode32 op = (OpCode32)context.CurrOp;
 62  
 63                  return Const((int)(op.GetPc() & 0xfffffffc));
 64              }
 65              else
 66              {
 67                  return Register(GetRegisterAlias(context.Mode, regIndex), RegisterType.Integer, OperandType.I32);
 68              }
 69          }
 70  
 71          public static Operand GetVecA32(int regIndex)
 72          {
 73              return Register(regIndex, RegisterType.Vector, OperandType.V128);
 74          }
 75  
 76          public static void SetIntA32(ArmEmitterContext context, int regIndex, Operand value)
 77          {
 78              if (regIndex == RegisterAlias.Aarch32Pc)
 79              {
 80                  if (!IsA32Return(context))
 81                  {
 82                      context.StoreToContext();
 83                  }
 84  
 85                  EmitBxWritePc(context, value);
 86              }
 87              else
 88              {
 89                  if (value.Type == OperandType.I64)
 90                  {
 91                      value = context.ConvertI64ToI32(value);
 92                  }
 93                  Operand reg = Register(GetRegisterAlias(context.Mode, regIndex), RegisterType.Integer, OperandType.I32);
 94  
 95                  context.Copy(reg, value);
 96              }
 97          }
 98  
 99          public static int GetRegisterAlias(Aarch32Mode mode, int regIndex)
100          {
101              // Only registers >= 8 are banked,
102              // with registers in the range [8, 12] being
103              // banked for the FIQ mode, and registers
104              // 13 and 14 being banked for all modes.
105              if ((uint)regIndex < 8)
106              {
107                  return regIndex;
108              }
109  
110              return GetBankedRegisterAlias(mode, regIndex);
111          }
112  
113          public static int GetBankedRegisterAlias(Aarch32Mode mode, int regIndex)
114          {
115              return regIndex switch
116              {
117  #pragma warning disable IDE0055 // Disable formatting
118                  8  => mode == Aarch32Mode.Fiq ? RegisterAlias.R8Fiq  : RegisterAlias.R8Usr,
119                  9  => mode == Aarch32Mode.Fiq ? RegisterAlias.R9Fiq  : RegisterAlias.R9Usr,
120                  10 => mode == Aarch32Mode.Fiq ? RegisterAlias.R10Fiq : RegisterAlias.R10Usr,
121                  11 => mode == Aarch32Mode.Fiq ? RegisterAlias.R11Fiq : RegisterAlias.R11Usr,
122                  12 => mode == Aarch32Mode.Fiq ? RegisterAlias.R12Fiq : RegisterAlias.R12Usr,
123                  13 => mode switch
124                  {
125                      Aarch32Mode.User or Aarch32Mode.System => RegisterAlias.SpUsr,
126                      Aarch32Mode.Fiq => RegisterAlias.SpFiq,
127                      Aarch32Mode.Irq => RegisterAlias.SpIrq,
128                      Aarch32Mode.Supervisor => RegisterAlias.SpSvc,
129                      Aarch32Mode.Abort => RegisterAlias.SpAbt,
130                      Aarch32Mode.Hypervisor => RegisterAlias.SpHyp,
131                      Aarch32Mode.Undefined => RegisterAlias.SpUnd,
132                      _ => throw new ArgumentException($"No such AArch32Mode: {mode}", nameof(mode)),
133                  },
134                  14 => mode switch
135                  {
136                      Aarch32Mode.User or Aarch32Mode.Hypervisor or Aarch32Mode.System => RegisterAlias.LrUsr,
137                      Aarch32Mode.Fiq => RegisterAlias.LrFiq,
138                      Aarch32Mode.Irq => RegisterAlias.LrIrq,
139                      Aarch32Mode.Supervisor => RegisterAlias.LrSvc,
140                      Aarch32Mode.Abort => RegisterAlias.LrAbt,
141                      Aarch32Mode.Undefined => RegisterAlias.LrUnd,
142                      _ => throw new ArgumentException($"No such AArch32Mode: {mode}", nameof(mode)),
143                  },
144                  _ => throw new ArgumentOutOfRangeException(nameof(regIndex), regIndex, null),
145  #pragma warning restore IDE0055
146              };
147          }
148  
149          public static bool IsA32Return(ArmEmitterContext context)
150          {
151              return context.CurrOp switch
152              {
153                  IOpCode32MemMult => true, // Setting PC using LDM is nearly always a return.
154                  OpCode32AluRsImm op => op.Rm == RegisterAlias.Aarch32Lr,
155                  OpCode32AluRsReg op => op.Rm == RegisterAlias.Aarch32Lr,
156                  OpCode32AluReg op => op.Rm == RegisterAlias.Aarch32Lr,
157                  OpCode32Mem op => op.Rn == RegisterAlias.Aarch32Sp && op.WBack && !op.Index, // Setting PC to an address stored on the stack is nearly always a return.
158                  _ => false,
159              };
160          }
161  
162          public static void EmitBxWritePc(ArmEmitterContext context, Operand pc, int sourceRegister = 0)
163          {
164              bool isReturn = sourceRegister == RegisterAlias.Aarch32Lr || IsA32Return(context);
165              Operand mode = context.BitwiseAnd(pc, Const(1));
166  
167              SetFlag(context, PState.TFlag, mode);
168  
169              Operand addr = context.ConditionalSelect(mode, context.BitwiseAnd(pc, Const(~1)), context.BitwiseAnd(pc, Const(~3)));
170  
171              InstEmitFlowHelper.EmitVirtualJump(context, addr, isReturn);
172          }
173  
174          public static Operand GetIntOrZR(ArmEmitterContext context, int regIndex)
175          {
176              if (regIndex == RegisterConsts.ZeroIndex)
177              {
178                  OperandType type = context.CurrOp.GetOperandType();
179  
180                  return type == OperandType.I32 ? Const(0) : Const(0L);
181              }
182              else
183              {
184                  return GetIntOrSP(context, regIndex);
185              }
186          }
187  
188          public static void SetIntOrZR(ArmEmitterContext context, int regIndex, Operand value)
189          {
190              if (regIndex == RegisterConsts.ZeroIndex)
191              {
192                  return;
193              }
194  
195              SetIntOrSP(context, regIndex, value);
196          }
197  
198          public static Operand GetIntOrSP(ArmEmitterContext context, int regIndex)
199          {
200              Operand value = Register(regIndex, RegisterType.Integer, OperandType.I64);
201  
202              if (context.CurrOp.RegisterSize == RegisterSize.Int32)
203              {
204                  value = context.ConvertI64ToI32(value);
205              }
206  
207              return value;
208          }
209  
210          public static void SetIntOrSP(ArmEmitterContext context, int regIndex, Operand value)
211          {
212              Operand reg = Register(regIndex, RegisterType.Integer, OperandType.I64);
213  
214              if (value.Type == OperandType.I32)
215              {
216                  value = context.ZeroExtend32(OperandType.I64, value);
217              }
218  
219              context.Copy(reg, value);
220          }
221  
222          public static Operand GetVec(int regIndex)
223          {
224              return Register(regIndex, RegisterType.Vector, OperandType.V128);
225          }
226  
227          public static Operand GetFlag(PState stateFlag)
228          {
229              return Register((int)stateFlag, RegisterType.Flag, OperandType.I32);
230          }
231  
232          public static Operand GetFpFlag(FPState stateFlag)
233          {
234              return Register((int)stateFlag, RegisterType.FpFlag, OperandType.I32);
235          }
236  
237          public static void SetFlag(ArmEmitterContext context, PState stateFlag, Operand value)
238          {
239              context.Copy(GetFlag(stateFlag), value);
240  
241              context.MarkFlagSet(stateFlag);
242          }
243  
244          public static void SetFpFlag(ArmEmitterContext context, FPState stateFlag, Operand value)
245          {
246              context.Copy(GetFpFlag(stateFlag), value);
247          }
248      }
249  }