Ryujinx/ChocolArm64/Decoders/OpCode32MemMult.cs
gdkchan c1bdf19061
Implement some ARM32 memory instructions and CMP (#565)
* Implement ARM32 memory instructions: LDM, LDR, LDRB, LDRD, LDRH, LDRSB, LDRSH, STM, STR, STRB, STRD, STRH (immediate and register + immediate variants), implement CMP (immediate and register shifted by immediate variants)

* Rename some opcode classes and flag masks for consistency

* Fix a few suboptimal ARM32 codegen issues, only loads should be considered on decoder when checking if Rt == PC, and only NZCV flags should be considered for comparison optimizations

* Take into account Rt2 for LDRD instructions aswell when checking if the instruction changes PC

* Re-align arm32 instructions on the opcode table
2019-01-29 13:06:11 -03:00

57 lines
1.4 KiB
C#

using ChocolArm64.Instructions;
namespace ChocolArm64.Decoders
{
class OpCode32MemMult : OpCode32, IOpCode32MemMult
{
public int Rn { get; private set; }
public int RegisterMask { get; private set; }
public int Offset { get; private set; }
public int PostOffset { get; private set; }
public bool IsLoad { get; private set; }
public OpCode32MemMult(Inst inst, long position, int opCode) : base(inst, position, opCode)
{
Rn = (opCode >> 16) & 0xf;
bool isLoad = (opCode & (1 << 20)) != 0;
bool w = (opCode & (1 << 21)) != 0;
bool u = (opCode & (1 << 23)) != 0;
bool p = (opCode & (1 << 24)) != 0;
RegisterMask = opCode & 0xffff;
int regsSize = 0;
for (int index = 0; index < 16; index++)
{
regsSize += (RegisterMask >> index) & 1;
}
regsSize *= 4;
if (!u)
{
Offset -= regsSize;
}
if (u == p)
{
Offset += 4;
}
if (w)
{
PostOffset = u ? regsSize : -regsSize;
}
else
{
PostOffset = 0;
}
IsLoad = isLoad;
}
}
}