ChocolArm64/Instructions/InstEmit32Helper.cs

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using ChocolArm64.Decoders;
using ChocolArm64.IntermediateRepresentation;
using ChocolArm64.State;
using ChocolArm64.Translation;
using System;
using System.Reflection.Emit;
namespace ChocolArm64.Instructions
{
static class InstEmit32Helper
{
public static bool IsThumb(OpCode64 op)
{
return op is OpCodeT16;
}
public static void EmitLoadFromRegister(ILEmitterCtx context, int register)
{
if (register == RegisterAlias.Aarch32Pc)
{
OpCode32 op = (OpCode32)context.CurrOp;
context.EmitLdc_I4((int)op.GetPc());
}
else
{
context.EmitLdint(GetRegisterAlias(context.Mode, register));
}
}
public static void EmitStoreToRegister(ILEmitterCtx context, int register)
{
if (register == RegisterAlias.Aarch32Pc)
{
context.EmitStoreContext();
EmitBxWritePc(context);
}
else
{
context.EmitStint(GetRegisterAlias(context.Mode, register));
}
}
public static void EmitBxWritePc(ILEmitterCtx context)
{
context.Emit(OpCodes.Dup);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.Emit(OpCodes.Dup);
context.EmitStflg((int)PState.TBit);
ILLabel lblArmMode = new ILLabel();
ILLabel lblEnd = new ILLabel();
context.Emit(OpCodes.Brtrue_S, lblArmMode);
context.EmitLdc_I4(~1);
context.Emit(OpCodes.Br_S, lblEnd);
context.MarkLabel(lblArmMode);
context.EmitLdc_I4(~3);
context.MarkLabel(lblEnd);
context.Emit(OpCodes.And);
context.Emit(OpCodes.Conv_U8);
context.Emit(OpCodes.Ret);
}
public static int GetRegisterAlias(Aarch32Mode mode, int register)
{
//Only registers >= 8 are banked, with registers in the range [8, 12] being
//banked for the FIQ mode, and registers 13 and 14 being banked for all modes.
if ((uint)register < 8)
{
return register;
}
return GetBankedRegisterAlias(mode, register);
}
public static int GetBankedRegisterAlias(Aarch32Mode mode, int register)
{
switch (register)
{
case 8: return mode == Aarch32Mode.Fiq
? RegisterAlias.R8Fiq
: RegisterAlias.R8Usr;
case 9: return mode == Aarch32Mode.Fiq
? RegisterAlias.R9Fiq
: RegisterAlias.R9Usr;
case 10: return mode == Aarch32Mode.Fiq
? RegisterAlias.R10Fiq
: RegisterAlias.R10Usr;
case 11: return mode == Aarch32Mode.Fiq
? RegisterAlias.R11Fiq
: RegisterAlias.R11Usr;
case 12: return mode == Aarch32Mode.Fiq
? RegisterAlias.R12Fiq
: RegisterAlias.R12Usr;
case 13:
switch (mode)
{
case Aarch32Mode.User:
case Aarch32Mode.System: return RegisterAlias.SpUsr;
case Aarch32Mode.Fiq: return RegisterAlias.SpFiq;
case Aarch32Mode.Irq: return RegisterAlias.SpIrq;
case Aarch32Mode.Supervisor: return RegisterAlias.SpSvc;
case Aarch32Mode.Abort: return RegisterAlias.SpAbt;
case Aarch32Mode.Hypervisor: return RegisterAlias.SpHyp;
case Aarch32Mode.Undefined: return RegisterAlias.SpUnd;
default: throw new ArgumentException(nameof(mode));
}
case 14:
switch (mode)
{
case Aarch32Mode.User:
case Aarch32Mode.Hypervisor:
case Aarch32Mode.System: return RegisterAlias.LrUsr;
case Aarch32Mode.Fiq: return RegisterAlias.LrFiq;
case Aarch32Mode.Irq: return RegisterAlias.LrIrq;
case Aarch32Mode.Supervisor: return RegisterAlias.LrSvc;
case Aarch32Mode.Abort: return RegisterAlias.LrAbt;
case Aarch32Mode.Undefined: return RegisterAlias.LrUnd;
default: throw new ArgumentException(nameof(mode));
}
default: throw new ArgumentOutOfRangeException(nameof(register));
}
}
}
}