R/ChocolArm64/Instructions/InstEmitAluHelper.cs

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using ChocolArm64.Decoders;
using ChocolArm64.State;
using ChocolArm64.Translation;
using System;
using System.Reflection.Emit;
namespace ChocolArm64.Instructions
{
static class InstEmitAluHelper
{
public static void EmitAdcsCCheck(ILEmitterCtx context)
{
//C = (Rd == Rn && CIn) || Rd < Rn
context.EmitSttmp();
context.EmitLdtmp();
context.EmitLdtmp();
EmitAluLoadRn(context);
context.Emit(OpCodes.Ceq);
context.EmitLdflg((int)PState.CBit);
context.Emit(OpCodes.And);
context.EmitLdtmp();
EmitAluLoadRn(context);
context.Emit(OpCodes.Clt_Un);
context.Emit(OpCodes.Or);
context.EmitStflg((int)PState.CBit);
}
public static void EmitAddsCCheck(ILEmitterCtx context)
{
//C = Rd < Rn
context.Emit(OpCodes.Dup);
EmitAluLoadRn(context);
context.Emit(OpCodes.Clt_Un);
context.EmitStflg((int)PState.CBit);
}
public static void EmitAddsVCheck(ILEmitterCtx context)
{
//V = (Rd ^ Rn) & ~(Rn ^ Rm) < 0
context.Emit(OpCodes.Dup);
EmitAluLoadRn(context);
context.Emit(OpCodes.Xor);
EmitAluLoadOpers(context);
context.Emit(OpCodes.Xor);
context.Emit(OpCodes.Not);
context.Emit(OpCodes.And);
context.EmitLdc_I(0);
context.Emit(OpCodes.Clt);
context.EmitStflg((int)PState.VBit);
}
public static void EmitSbcsCCheck(ILEmitterCtx context)
{
//C = (Rn == Rm && CIn) || Rn > Rm
EmitAluLoadOpers(context);
context.Emit(OpCodes.Ceq);
context.EmitLdflg((int)PState.CBit);
context.Emit(OpCodes.And);
EmitAluLoadOpers(context);
context.Emit(OpCodes.Cgt_Un);
context.Emit(OpCodes.Or);
context.EmitStflg((int)PState.CBit);
}
public static void EmitSubsCCheck(ILEmitterCtx context)
{
//C = Rn == Rm || Rn > Rm = !(Rn < Rm)
EmitAluLoadOpers(context);
context.Emit(OpCodes.Clt_Un);
context.EmitLdc_I4(1);
context.Emit(OpCodes.Xor);
context.EmitStflg((int)PState.CBit);
}
public static void EmitSubsVCheck(ILEmitterCtx context)
{
//V = (Rd ^ Rn) & (Rn ^ Rm) < 0
context.Emit(OpCodes.Dup);
EmitAluLoadRn(context);
context.Emit(OpCodes.Xor);
EmitAluLoadOpers(context);
context.Emit(OpCodes.Xor);
context.Emit(OpCodes.And);
context.EmitLdc_I(0);
context.Emit(OpCodes.Clt);
context.EmitStflg((int)PState.VBit);
}
public static void EmitAluLoadRm(ILEmitterCtx context)
{
if (context.CurrOp is IOpCodeAluRs64 op)
{
context.EmitLdintzr(op.Rm);
}
else if (context.CurrOp is OpCode32AluRsImm op32)
{
InstEmit32Helper.EmitLoadFromRegister(context, op32.Rm);
}
else
{
throw new InvalidOperationException();
}
}
public static void EmitAluLoadOpers(ILEmitterCtx context, bool setCarry = true)
{
EmitAluLoadRn(context);
EmitAluLoadOper2(context, setCarry);
}
public static void EmitAluLoadRn(ILEmitterCtx context)
{
if (context.CurrOp is IOpCodeAlu64 op)
{
if (op.DataOp == DataOp.Logical || op is IOpCodeAluRs64)
{
context.EmitLdintzr(op.Rn);
}
else
{
context.EmitLdint(op.Rn);
}
}
else if (context.CurrOp is IOpCode32Alu op32)
{
InstEmit32Helper.EmitLoadFromRegister(context, op32.Rn);
}
else
{
throw new InvalidOperationException();
}
}
public static void EmitAluLoadOper2(ILEmitterCtx context, bool setCarry = true)
{
switch (context.CurrOp)
{
//ARM32.
case OpCode32AluImm op:
context.EmitLdc_I4(op.Imm);
if (op.SetFlags && op.IsRotated)
{
context.EmitLdc_I4((int)((uint)op.Imm >> 31));
context.EmitStflg((int)PState.CBit);
}
break;
case OpCode32AluRsImm op:
EmitLoadRmShiftedByImmediate(context, op, setCarry);
break;
case OpCodeT16AluImm8 op:
context.EmitLdc_I4(op.Imm);
break;
//ARM64.
case IOpCodeAluImm64 op:
context.EmitLdc_I(op.Imm);
break;
case IOpCodeAluRs64 op:
context.EmitLdintzr(op.Rm);
switch (op.ShiftType)
{
case ShiftType.Lsl: context.EmitLsl(op.Shift); break;
case ShiftType.Lsr: context.EmitLsr(op.Shift); break;
case ShiftType.Asr: context.EmitAsr(op.Shift); break;
case ShiftType.Ror: context.EmitRor(op.Shift); break;
}
break;
case IOpCodeAluRx64 op:
context.EmitLdintzr(op.Rm);
context.EmitCast(op.IntType);
context.EmitLsl(op.Shift);
break;
default: throw new InvalidOperationException();
}
}
public static void EmitSetNzcv(ILEmitterCtx context)
{
context.Emit(OpCodes.Dup);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.VBit);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.Shr);
context.Emit(OpCodes.Dup);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.Shr);
context.Emit(OpCodes.Dup);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.ZBit);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.Shr);
context.Emit(OpCodes.Ldc_I4_1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.NBit);
}
//ARM32 helpers.
private static void EmitLoadRmShiftedByImmediate(ILEmitterCtx context, OpCode32AluRsImm op, bool setCarry)
{
int shift = op.Imm;
if (shift == 0)
{
switch (op.ShiftType)
{
case ShiftType.Lsr: shift = 32; break;
case ShiftType.Asr: shift = 32; break;
case ShiftType.Ror: shift = 1; break;
}
}
context.EmitLdint(op.Rm);
if (shift != 0)
{
setCarry &= op.SetFlags;
switch (op.ShiftType)
{
case ShiftType.Lsl: EmitLslC(context, setCarry, shift); break;
case ShiftType.Lsr: EmitLsrC(context, setCarry, shift); break;
case ShiftType.Asr: EmitAsrC(context, setCarry, shift); break;
case ShiftType.Ror:
if (op.Imm != 0)
{
EmitRorC(context, setCarry, shift);
}
else
{
EmitRrxC(context, setCarry);
}
break;
}
}
}
private static void EmitLslC(ILEmitterCtx context, bool setCarry, int shift)
{
if ((uint)shift > 32)
{
EmitShiftByMoreThan32(context, setCarry);
}
else if (shift == 32)
{
if (setCarry)
{
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
}
else
{
context.Emit(OpCodes.Pop);
}
context.EmitLdc_I4(0);
}
else
{
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitLsr(32 - shift);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
}
context.EmitLsl(shift);
}
}
private static void EmitLsrC(ILEmitterCtx context, bool setCarry, int shift)
{
if ((uint)shift > 32)
{
EmitShiftByMoreThan32(context, setCarry);
}
else if (shift == 32)
{
if (setCarry)
{
context.EmitLsr(31);
context.EmitStflg((int)PState.CBit);
}
else
{
context.Emit(OpCodes.Pop);
}
context.EmitLdc_I4(0);
}
else
{
context.Emit(OpCodes.Dup);
context.EmitLsr(shift - 1);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
context.EmitLsr(shift);
}
}
private static void EmitShiftByMoreThan32(ILEmitterCtx context, bool setCarry)
{
context.Emit(OpCodes.Pop);
context.EmitLdc_I4(0);
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitStflg((int)PState.CBit);
}
}
private static void EmitAsrC(ILEmitterCtx context, bool setCarry, int shift)
{
if ((uint)shift >= 32)
{
context.EmitAsr(31);
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
}
}
else
{
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitLsr(shift - 1);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitStflg((int)PState.CBit);
}
context.EmitAsr(shift);
}
}
private static void EmitRorC(ILEmitterCtx context, bool setCarry, int shift)
{
shift &= 0x1f;
context.EmitRor(shift);
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitLsr(31);
context.EmitStflg((int)PState.CBit);
}
}
private static void EmitRrxC(ILEmitterCtx context, bool setCarry)
{
//Rotate right by 1 with carry.
if (setCarry)
{
context.Emit(OpCodes.Dup);
context.EmitLdc_I4(1);
context.Emit(OpCodes.And);
context.EmitSttmp();
}
context.EmitLsr(1);
context.EmitLdflg((int)PState.CBit);
context.EmitLsl(31);
context.Emit(OpCodes.Or);
if (setCarry)
{
context.EmitLdtmp();
context.EmitStflg((int)PState.CBit);
}
}
}
}