53 lines
1.6 KiB
C#
53 lines
1.6 KiB
C#
|
using ChocolArm64.Instruction;
|
||
|
|
|
||
|
|
namespace ChocolArm64.Decoder
|
||
|
|
{
|
||
|
|
class AOpCodeMemImm : AOpCodeMem
|
||
|
|
{
|
||
|
|
public long Imm { get; protected set; }
|
||
|
|
public bool WBack { get; protected set; }
|
||
|
|
public bool PostIdx { get; protected set; }
|
||
|
|
protected bool Unscaled { get; private set; }
|
||
|
|
|
||
|
|
private enum MemOp
|
||
|
|
{
|
||
|
|
Unscaled = 0,
|
||
|
|
PostIndexed = 1,
|
||
|
|
Unprivileged = 2,
|
||
|
|
PreIndexed = 3,
|
||
|
|
Unsigned
|
||
|
|
}
|
||
|
|
|
||
|
|
public AOpCodeMemImm(AInst Inst, long Position, int OpCode) : base(Inst, Position, OpCode)
|
||
|
|
{
|
||
|
|
Extend64 = ((OpCode >> 22) & 3) == 2;
|
||
|
|
WBack = ((OpCode >> 24) & 1) == 0;
|
||
|
|
|
||
|
|
//The type is not valid for the Unsigned Immediate 12-bits encoding,
|
||
|
|
//because the bits 11:10 are used for the larger Immediate offset.
|
||
|
|
MemOp Type = WBack ? (MemOp)((OpCode >> 10) & 3) : MemOp.Unsigned;
|
||
|
|
|
||
|
|
PostIdx = Type == MemOp.PostIndexed;
|
||
|
|
Unscaled = Type == MemOp.Unscaled ||
|
||
|
|
Type == MemOp.Unprivileged;
|
||
|
|
|
||
|
|
//Unscaled and Unprivileged doesn't write back,
|
||
|
|
//but they do use the 9-bits Signed Immediate.
|
||
|
|
if (Unscaled)
|
||
|
|
{
|
||
|
|
WBack = false;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (WBack || Unscaled)
|
||
|
|
{
|
||
|
|
//9-bits Signed Immediate.
|
||
|
|
Imm = (OpCode << 43) >> 55;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
//12-bits Unsigned Immediate.
|
||
|
|
Imm = ((OpCode >> 10) & 0xfff) << Size;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|