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path: root/ChocolArm64/Decoder/AOpCodeSimdImm.cs
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Diffstat (limited to 'ChocolArm64/Decoder/AOpCodeSimdImm.cs')
-rw-r--r--ChocolArm64/Decoder/AOpCodeSimdImm.cs94
1 files changed, 94 insertions, 0 deletions
diff --git a/ChocolArm64/Decoder/AOpCodeSimdImm.cs b/ChocolArm64/Decoder/AOpCodeSimdImm.cs
new file mode 100644
index 00000000..2959aee6
--- /dev/null
+++ b/ChocolArm64/Decoder/AOpCodeSimdImm.cs
@@ -0,0 +1,94 @@
+using ChocolArm64.Instruction;
+using ChocolArm64.State;
+
+namespace ChocolArm64.Decoder
+{
+ class AOpCodeSimdImm : AOpCode, IAOpCodeSimd
+ {
+ public int Rd { get; private set; }
+ public long Imm { get; private set; }
+ public int Size { get; private set; }
+
+ public AOpCodeSimdImm(AInst Inst, long Position, int OpCode) : base(Inst, Position, OpCode)
+ {
+ Rd = OpCode & 0x1f;
+
+ int CMode = (OpCode >> 12) & 0xf;
+ int Op = (OpCode >> 29) & 0x1;
+
+ int ModeLow = CMode & 1;
+ int ModeHigh = CMode >> 1;
+
+ long Imm;
+
+ Imm = ((uint)OpCode >> 5) & 0x1f;
+ Imm |= ((uint)OpCode >> 11) & 0xe0;
+
+ if (ModeHigh == 0b111)
+ {
+ Size = ModeLow != 0 ? Op : 3;
+
+ switch (Op | (ModeLow << 1))
+ {
+ case 0:
+ //64-bits Immediate.
+ //Transform abcd efgh into abcd efgh abcd efgh ...
+ Imm = (long)((ulong)Imm * 0x0101010101010101);
+ break;
+
+ case 1:
+ //64-bits Immediate.
+ //Transform abcd efgh into aaaa aaaa bbbb bbbb ...
+ Imm = (Imm & 0xf0) >> 4 | (Imm & 0x0f) << 4;
+ Imm = (Imm & 0xcc) >> 2 | (Imm & 0x33) << 2;
+ Imm = (Imm & 0xaa) >> 1 | (Imm & 0x55) << 1;
+
+ Imm = (long)((ulong)Imm * 0x8040201008040201);
+ Imm = (long)((ulong)Imm & 0x8080808080808080);
+
+ Imm |= Imm >> 4;
+ Imm |= Imm >> 2;
+ Imm |= Imm >> 1;
+ break;
+
+ case 2:
+ case 3:
+ //Floating point Immediate.
+ Imm = ADecoderHelper.DecodeImm8Float(Imm, Size);
+ break;
+ }
+ }
+ else if ((ModeHigh & 0b110) == 0b100)
+ {
+ //16-bits shifted Immediate.
+ Size = 1; Imm <<= (ModeHigh & 1) << 3;
+ }
+ else if ((ModeHigh & 0b100) == 0b000)
+ {
+ //32-bits shifted Immediate.
+ Size = 2; Imm <<= ModeHigh << 3;
+ }
+ else if ((ModeHigh & 0b111) == 0b110)
+ {
+ //32-bits shifted Immediate (fill with ones).
+ Size = 2; Imm = ShlOnes(Imm, 8 << ModeLow);
+ }
+ else
+ {
+ //8 bits without shift.
+ Size = 0;
+ }
+
+ this.Imm = Imm;
+
+ RegisterSize = ((OpCode >> 30) & 1) != 0
+ ? ARegisterSize.SIMD128
+ : ARegisterSize.SIMD64;
+ }
+
+ private static long ShlOnes(long Value, int Shift)
+ {
+ return Value << Shift | (long)(ulong.MaxValue >> (64 - Shift));
+ }
+ }
+} \ No newline at end of file