ChocolArm64/Decoders/OpCodeMemImm64.cs
gdkchan 01d9716d20 Misc. CPU improvements (#519)
* Fix and simplify TranslatorCache

* Fix some assignment alignments, remove some unused usings

* Changes to ILEmitter, separate it from ILEmitterCtx

* Rename ILEmitter to ILMethodBuilder

* Rename LdrLit and *_Fix opcodes

* Revert TranslatorCache impl to the more performant one, fix a few issues with it

* Allow EmitOpCode to be called even after everything has been emitted

* Make Emit and AdvanceOpCode private, simplify it a bit now that it starts emiting from the entry point

* Remove unneeded temp use

* Add missing exit call on TestExclusive

* Use better hash

* Implement the == and != operators
2018-12-10 22:58:52 -02:00

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C#

using ChocolArm64.Instructions;
namespace ChocolArm64.Decoders
{
class OpCodeMemImm64 : OpCodeMem64
{
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 OpCodeMemImm64(Inst 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 << 11) >> 23;
}
else
{
//12-bits Unsigned Immediate.
Imm = ((opCode >> 10) & 0xfff) << Size;
}
}
}
}