rjx-mirror/ARMeilleure/Instructions/InstEmitHelper.cs
FICTURE7 4c7bebf3e6
Do not emit StoreToContext before Return (#1537)
* Do not emit StoreToContext before Return

* Set PPTC version
2020-09-07 12:52:17 +10:00

255 lines
9 KiB
C#

using ARMeilleure.Decoders;
using ARMeilleure.IntermediateRepresentation;
using ARMeilleure.State;
using ARMeilleure.Translation;
using System;
using static ARMeilleure.IntermediateRepresentation.OperandHelper;
namespace ARMeilleure.Instructions
{
static class InstEmitHelper
{
public static bool IsThumb(OpCode op)
{
return op is OpCodeT16;
}
public static Operand GetExtendedM(ArmEmitterContext context, int rm, IntType type)
{
Operand value = GetIntOrZR(context, rm);
switch (type)
{
case IntType.UInt8: value = context.ZeroExtend8 (value.Type, value); break;
case IntType.UInt16: value = context.ZeroExtend16(value.Type, value); break;
case IntType.UInt32: value = context.ZeroExtend32(value.Type, value); break;
case IntType.Int8: value = context.SignExtend8 (value.Type, value); break;
case IntType.Int16: value = context.SignExtend16(value.Type, value); break;
case IntType.Int32: value = context.SignExtend32(value.Type, value); break;
}
return value;
}
public static Operand GetIntA32(ArmEmitterContext context, int regIndex)
{
if (regIndex == RegisterAlias.Aarch32Pc)
{
OpCode32 op = (OpCode32)context.CurrOp;
return Const((int)op.GetPc());
}
else
{
return Register(GetRegisterAlias(context.Mode, regIndex), RegisterType.Integer, OperandType.I32);
}
}
public static Operand GetVecA32(int regIndex)
{
return Register(regIndex, RegisterType.Vector, OperandType.V128);
}
public static void SetIntA32(ArmEmitterContext context, int regIndex, Operand value)
{
if (regIndex == RegisterAlias.Aarch32Pc)
{
if (!IsA32Return(context))
{
context.StoreToContext();
}
EmitBxWritePc(context, value);
}
else
{
if (value.Type == OperandType.I64)
{
value = context.ConvertI64ToI32(value);
}
Operand reg = Register(GetRegisterAlias(context.Mode, regIndex), RegisterType.Integer, OperandType.I32);
context.Copy(reg, value);
}
}
public static int GetRegisterAlias(Aarch32Mode mode, int regIndex)
{
// 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)regIndex < 8)
{
return regIndex;
}
return GetBankedRegisterAlias(mode, regIndex);
}
public static int GetBankedRegisterAlias(Aarch32Mode mode, int regIndex)
{
switch (regIndex)
{
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(regIndex));
}
}
public static bool IsA32Return(ArmEmitterContext context)
{
switch (context.CurrOp)
{
case IOpCode32MemMult op:
return true; // Setting PC using LDM is nearly always a return.
case OpCode32AluRsImm op:
return op.Rm == RegisterAlias.Aarch32Lr;
case OpCode32AluRsReg op:
return op.Rm == RegisterAlias.Aarch32Lr;
case OpCode32AluReg op:
return op.Rm == RegisterAlias.Aarch32Lr;
case OpCode32Mem op:
return op.Rn == RegisterAlias.Aarch32Sp && op.WBack && !op.Index; // Setting PC to an address stored on the stack is nearly always a return.
}
return false;
}
public static void EmitBxWritePc(ArmEmitterContext context, Operand pc, int sourceRegister = 0)
{
bool isReturn = sourceRegister == RegisterAlias.Aarch32Lr || IsA32Return(context);
Operand mode = context.BitwiseAnd(pc, Const(1));
SetFlag(context, PState.TFlag, mode);
Operand addr = context.ConditionalSelect(mode, context.BitwiseOr(pc, Const((int)InstEmitFlowHelper.CallFlag)), context.BitwiseAnd(pc, Const(~3)));
InstEmitFlowHelper.EmitVirtualJump(context, addr, isReturn);
}
public static Operand GetIntOrZR(ArmEmitterContext context, int regIndex)
{
if (regIndex == RegisterConsts.ZeroIndex)
{
OperandType type = context.CurrOp.GetOperandType();
return type == OperandType.I32 ? Const(0) : Const(0L);
}
else
{
return GetIntOrSP(context, regIndex);
}
}
public static void SetIntOrZR(ArmEmitterContext context, int regIndex, Operand value)
{
if (regIndex == RegisterConsts.ZeroIndex)
{
return;
}
SetIntOrSP(context, regIndex, value);
}
public static Operand GetIntOrSP(ArmEmitterContext context, int regIndex)
{
Operand value = Register(regIndex, RegisterType.Integer, OperandType.I64);
if (context.CurrOp.RegisterSize == RegisterSize.Int32)
{
value = context.ConvertI64ToI32(value);
}
return value;
}
public static void SetIntOrSP(ArmEmitterContext context, int regIndex, Operand value)
{
Operand reg = Register(regIndex, RegisterType.Integer, OperandType.I64);
if (value.Type == OperandType.I32)
{
value = context.ZeroExtend32(OperandType.I64, value);
}
context.Copy(reg, value);
}
public static Operand GetVec(int regIndex)
{
return Register(regIndex, RegisterType.Vector, OperandType.V128);
}
public static Operand GetFlag(PState stateFlag)
{
return Register((int)stateFlag, RegisterType.Flag, OperandType.I32);
}
public static Operand GetFpFlag(FPState stateFlag)
{
return Register((int)stateFlag, RegisterType.FpFlag, OperandType.I32);
}
public static void SetFlag(ArmEmitterContext context, PState stateFlag, Operand value)
{
context.Copy(GetFlag(stateFlag), value);
context.MarkFlagSet(stateFlag);
}
public static void SetFpFlag(ArmEmitterContext context, FPState stateFlag, Operand value)
{
context.Copy(GetFpFlag(stateFlag), value);
}
}
}