Ryujinx/ChocolArm64/Instruction32/A32InstInterpretHelper.cs

65 lines
No EOL
2.2 KiB
C#

using ChocolArm64.Decoder;
using ChocolArm64.State;
using System;
namespace ChocolArm64.Instruction32
{
static class A32InstInterpretHelper
{
public static bool IsConditionTrue(AThreadState State, ACond Cond)
{
switch (Cond)
{
case ACond.Eq: return State.Zero;
case ACond.Ne: return !State.Zero;
case ACond.Ge_Un: return State.Carry;
case ACond.Lt_Un: return !State.Carry;
case ACond.Mi: return State.Negative;
case ACond.Pl: return !State.Negative;
case ACond.Vs: return State.Overflow;
case ACond.Vc: return !State.Overflow;
case ACond.Gt_Un: return State.Carry && !State.Zero;
case ACond.Le_Un: return !State.Carry && State.Zero;
case ACond.Ge: return State.Negative == State.Overflow;
case ACond.Lt: return State.Negative != State.Overflow;
case ACond.Gt: return State.Negative == State.Overflow && !State.Zero;
case ACond.Le: return State.Negative != State.Overflow && State.Zero;
}
return true;
}
public unsafe static uint GetReg(AThreadState State, int Reg)
{
if ((uint)Reg > 15)
{
throw new ArgumentOutOfRangeException(nameof(Reg));
}
fixed (uint* Ptr = &State.R0)
{
return *(Ptr + Reg);
}
}
public unsafe static void SetReg(AThreadState State, int Reg, uint Value)
{
if ((uint)Reg > 15)
{
throw new ArgumentOutOfRangeException(nameof(Reg));
}
fixed (uint* Ptr = &State.R0)
{
*(Ptr + Reg) = Value;
}
}
public static uint GetPc(AThreadState State)
{
//Due to the old fetch-decode-execute pipeline of old ARM CPUs,
//the PC is 4 or 8 bytes (2 instructions) ahead of the current instruction.
return State.R15 + (State.Thumb ? 2U : 4U);
}
}
}