diff options
| author | TSR Berry <20988865+TSRBerry@users.noreply.github.com> | 2023-04-08 01:22:00 +0200 |
|---|---|---|
| committer | Mary <thog@protonmail.com> | 2023-04-27 23:51:14 +0200 |
| commit | cee712105850ac3385cd0091a923438167433f9f (patch) | |
| tree | 4a5274b21d8b7f938c0d0ce18736d3f2993b11b1 /src/ARMeilleure/Decoders/OpCodeMemImm.cs | |
| parent | cd124bda587ef09668a971fa1cac1c3f0cfc9f21 (diff) | |
Move solution and projects to src
Diffstat (limited to 'src/ARMeilleure/Decoders/OpCodeMemImm.cs')
| -rw-r--r-- | src/ARMeilleure/Decoders/OpCodeMemImm.cs | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/ARMeilleure/Decoders/OpCodeMemImm.cs b/src/ARMeilleure/Decoders/OpCodeMemImm.cs new file mode 100644 index 00000000..d6ed2282 --- /dev/null +++ b/src/ARMeilleure/Decoders/OpCodeMemImm.cs @@ -0,0 +1,53 @@ +namespace ARMeilleure.Decoders +{ + class OpCodeMemImm : OpCodeMem + { + public long Immediate { get; protected set; } + public bool WBack { get; protected set; } + public bool PostIdx { get; protected set; } + protected bool Unscaled { get; } + + private enum MemOp + { + Unscaled = 0, + PostIndexed = 1, + Unprivileged = 2, + PreIndexed = 3, + Unsigned + } + + public new static OpCode Create(InstDescriptor inst, ulong address, int opCode) => new OpCodeMemImm(inst, address, opCode); + + public OpCodeMemImm(InstDescriptor inst, ulong address, int opCode) : base(inst, address, 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. + Immediate = (opCode << 11) >> 23; + } + else + { + // 12-bits Unsigned Immediate. + Immediate = ((opCode >> 10) & 0xfff) << Size; + } + } + } +}
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