public static void Parse(IEnumerable<NasmEncodingToken> tokens, VexOpcodeEncoding vexEncoding,
out Opcode opcode, out InstructionEncoding encoding)
{
Contract.Requires(tokens != null);
var parser = new EncodingParser();
parser.Parse(tokens, vexEncoding);
opcode = parser.opcode;
encoding = parser.encoding;
}
private void Parse(IEnumerable<NasmEncodingToken> tokens, VexOpcodeEncoding vexEncoding)
{
state = State.Prefixes;
bool hasVex = false;
NasmEncodingTokenType addressSize = 0;
foreach (var token in tokens)
{
switch (token.Type)
{
case NasmEncodingTokenType.Vex:
Contract.Assert(!hasVex);
SetVex(vexEncoding);
hasVex = true;
break;
case NasmEncodingTokenType.AddressSize_Fixed16:
case NasmEncodingTokenType.AddressSize_Fixed32:
case NasmEncodingTokenType.AddressSize_Fixed64:
case NasmEncodingTokenType.AddressSize_NoOverride:
Contract.Assert(state == State.Prefixes);
Contract.Assert(addressSize == 0);
addressSize = token.Type;
break;
case NasmEncodingTokenType.OperandSize_16:
SetOperandSize(InstructionEncoding.OperandSize_Fixed16);
break;
case NasmEncodingTokenType.OperandSize_32:
SetOperandSize(InstructionEncoding.OperandSize_Fixed32);
break;
case NasmEncodingTokenType.OperandSize_64:
SetOperandSize(InstructionEncoding.OperandSize_Fixed64);
break;
case NasmEncodingTokenType.OperandSize_64WithoutW:
{
InstructionEncoding newOperandSize;
switch (encoding & InstructionEncoding.OperandSize_Mask)
{
case 0:
newOperandSize = InstructionEncoding.OperandSize_16Or32Or64;
break;
case InstructionEncoding.OperandSize_Fixed16:
newOperandSize = InstructionEncoding.OperandSize_16Or32Or64;
break;
case InstructionEncoding.OperandSize_Fixed32:
newOperandSize = InstructionEncoding.OperandSize_32Or64;
break;
default: throw new InvalidDataException();
}
encoding &= ~InstructionEncoding.OperandSize_Mask;
SetOperandSize(newOperandSize);
}
break;
case NasmEncodingTokenType.OperandSize_NoOverride:
// TODO: What does this mean for the instruction encoding?
SetOperandSize(InstructionEncoding.OperandSize_16Or32);
break;
// Legacy prefixes
case NasmEncodingTokenType.LegacyPrefix_F2:
SetSimdPrefix(SimdPrefix._F2);
continue;
case NasmEncodingTokenType.LegacyPrefix_MustRep:
case NasmEncodingTokenType.LegacyPrefix_F3:
SetSimdPrefix(SimdPrefix._F3);
continue;
case NasmEncodingTokenType.LegacyPrefix_NoSimd:
case NasmEncodingTokenType.LegacyPrefix_NoF3:
case NasmEncodingTokenType.LegacyPrefix_HleAlways:
case NasmEncodingTokenType.LegacyPrefix_HleWithLock:
case NasmEncodingTokenType.LegacyPrefix_XReleaseAlways:
case NasmEncodingTokenType.LegacyPrefix_DisassembleRepAsRepE:
case NasmEncodingTokenType.LegacyPrefix_NoRep:
break;
// Rex
case NasmEncodingTokenType.Rex_NoB:
case NasmEncodingTokenType.Rex_NoW: // TODO: handle this?
case NasmEncodingTokenType.Rex_LockAsRexR: // TODO: implies operand size 32
break;
case NasmEncodingTokenType.Byte:
if (state < State.PostSimdPrefix)
{
switch (token.Byte)
{
case 0x66: SetSimdPrefix(SimdPrefix._66); continue;
case 0xF2: SetSimdPrefix(SimdPrefix._F2); continue;
case 0xF3: SetSimdPrefix(SimdPrefix._F3); continue;
}
}
if (state < State.PostOpcode)
{
if (!hasVex)
{
if ((opcode & Opcode.Map_Mask) == Opcode.Map_Default
&& token.Byte == 0x0F)
{
opcode = opcode.WithMap(OpcodeMap.Escape0F);
AdvanceTo(State.Map0F);
continue;
}
if ((opcode & Opcode.Map_Mask) == Opcode.Map_0F
&& (token.Byte == 0x38 || token.Byte == 0x3A))
{
opcode = opcode.WithMap(
token.Byte == 0x38 ? OpcodeMap.Escape0F38 : OpcodeMap.Escape0F3A);
AdvanceTo(State.PostMap);
continue;
}
}
SetOpcode(InstructionEncoding.OpcodeFormat_FixedByte, token.Byte);
continue;
}
if (state == State.PostOpcode)
{
SetModRM(InstructionEncoding.ModRM_Fixed, token.Byte);
continue;
}
Contract.Assert(state == State.PostModRM);
opcode = opcode.WithExtraByte(token.Byte);
AddImmediate(ImmediateSize.Fixed8); // Opcode extension byte
break;
case NasmEncodingTokenType.Byte_PlusRegister:
Contract.Assert((token.Byte & 7) == 0);
if (state < State.PostOpcode)
{
SetOpcode(InstructionEncoding.OpcodeFormat_EmbeddedRegister, token.Byte);
continue;
}
if (state < State.PostModRM)
{
SetModRM(InstructionEncoding.ModRM_FixedModReg, token.Byte);
continue;
}
throw new FormatException();
case NasmEncodingTokenType.Byte_PlusConditionCode:
// TODO: figure out what this means: [i: 71+c jlen e9 rel]
Contract.Assert(state < State.PostOpcode);
SetOpcode(InstructionEncoding.OpcodeFormat_EmbeddedConditionCode, (byte)(token.Byte & 0xF0));
continue;
case NasmEncodingTokenType.ModRM:
SetModRM(InstructionEncoding.ModRM_Any);
break;
case NasmEncodingTokenType.ModRM_FixedReg:
SetModRM(InstructionEncoding.ModRM_FixedReg, (byte)(token.Byte << 3));
break;
// Immediates
case NasmEncodingTokenType.Immediate_Byte:
case NasmEncodingTokenType.Immediate_Byte_Signed:
case NasmEncodingTokenType.Immediate_Byte_Unsigned:
case NasmEncodingTokenType.Immediate_RelativeOffset8:
case NasmEncodingTokenType.Immediate_Is4:
AddImmediate(ImmediateSize.Fixed8);
break;
case NasmEncodingTokenType.Immediate_Word:
case NasmEncodingTokenType.Immediate_Segment: // TODO: Make sure this happens in the right order
AddImmediate(ImmediateSize.Fixed16);
break;
case NasmEncodingTokenType.Immediate_Dword:
case NasmEncodingTokenType.Immediate_Dword_Signed:
AddImmediate(ImmediateSize.Fixed32);
break;
case NasmEncodingTokenType.Immediate_WordOrDword:
AddImmediate(ImmediateSize.Operand16Or32);
break;
case NasmEncodingTokenType.Immediate_WordOrDwordOrQword:
AddImmediate(ImmediateSize.Operand16Or32Or64);
break;
case NasmEncodingTokenType.Immediate_Qword:
AddImmediate(ImmediateSize.Fixed64);
break;
case NasmEncodingTokenType.Immediate_RelativeOffset:
switch (encoding & InstructionEncoding.OperandSize_Mask)
{
case InstructionEncoding.OperandSize_Ignored: AddImmediate(ImmediateSize.Operand16Or32); break;
case InstructionEncoding.OperandSize_Fixed16: AddImmediate(ImmediateSize.Fixed16); break;
case InstructionEncoding.OperandSize_Fixed32: AddImmediate(ImmediateSize.Fixed32); break;
case InstructionEncoding.OperandSize_Fixed64: AddImmediate(ImmediateSize.Fixed64); break;
case InstructionEncoding.OperandSize_16Or32: AddImmediate(ImmediateSize.Operand16Or32); break;
case InstructionEncoding.OperandSize_16Or32Or64: AddImmediate(ImmediateSize.Operand16Or32Or64); break;
default: throw new InvalidDataException();
}
break;
// Jump, it's not clear what additional info these provides so skip
case NasmEncodingTokenType.Jump_8:
case NasmEncodingTokenType.Jump_Conditional8:
case NasmEncodingTokenType.Jump_Length:
break;
// Misc
case NasmEncodingTokenType.VectorSib_XmmDwordIndices:
case NasmEncodingTokenType.VectorSib_XmmQwordIndices:
case NasmEncodingTokenType.VectorSib_YmmDwordIndices:
case NasmEncodingTokenType.VectorSib_YmmQwordIndices:
case NasmEncodingTokenType.VectorSib_ZmmDwordIndices:
case NasmEncodingTokenType.VectorSib_ZmmQwordIndices:
break; // doesn't impact encoding
case NasmEncodingTokenType.Misc_NoHigh8Register:
case NasmEncodingTokenType.Misc_AssembleWaitPrefix: // Implicit WAIT prefix when assembling instruction
case NasmEncodingTokenType.Misc_Resb:
break;
default:
throw new NotImplementedException("Handling NASM encoding tokens of type '{0}'".FormatInvariant(token.Type));
}
}
}
private void SetVex(VexOpcodeEncoding vexEncoding)
{
Contract.Requires((opcode & Opcode.XexType_Mask) == Opcode.XexType_LegacyOrRex);
Contract.Requires((opcode & Opcode.SimdPrefix_Mask) == Opcode.SimdPrefix_None);
Opcode opcodeFromVex;
InstructionEncoding encodingFromVex;
vexEncoding.ToOpcodeEncoding(out opcodeFromVex, out encodingFromVex);
// TODO: Make sure these or's are safe
opcode |= opcodeFromVex;
encoding |= encodingFromVex;
AdvanceTo(State.PostMap);
}
private static void ParseVex_RexW(ref VexOpcodeEncoding encoding, string[] tokens, ref int tokenIndex)
{
if (tokenIndex == tokens.Length) return;
switch (tokens[tokenIndex++])
{
case "w0": encoding |= VexOpcodeEncoding.RexW_0; break;
case "w1": encoding |= VexOpcodeEncoding.RexW_1; break;
case "wig": encoding |= VexOpcodeEncoding.RexW_Ignored; break;
default: encoding |= VexOpcodeEncoding.RexW_Ignored; return;
}
}
private static void ParseVex_Map(ref VexOpcodeEncoding encoding, string[] tokens, ref int tokenIndex)
{
switch (tokens[tokenIndex++]) // Mandatory
{
case "0f": encoding |= VexOpcodeEncoding.Map_0F; break;
case "0f38": encoding |= VexOpcodeEncoding.Map_0F38; break;
case "m3": case "0f3a": encoding |= VexOpcodeEncoding.Map_0F3A; break;
case "m8": encoding |= VexOpcodeEncoding.Map_Xop8; break;
case "m9": encoding |= VexOpcodeEncoding.Map_Xop9; break;
case "m10": encoding |= VexOpcodeEncoding.Map_Xop10; break;
default: throw new FormatException();
}
}
private static void ParseVex_SimdPrefix_AmdStyle(ref VexOpcodeEncoding encoding, string[] tokens, ref int tokenIndex)
{
switch (tokens[tokenIndex])
{
case "p0": encoding |= VexOpcodeEncoding.SimdPrefix_None; break;
case "p1": encoding |= VexOpcodeEncoding.SimdPrefix_66; break;
default: encoding |= VexOpcodeEncoding.SimdPrefix_None; return;
}
++tokenIndex;
}
private static void ParseVex_VectorLength(ref VexOpcodeEncoding encoding, string[] tokens, ref int tokenIndex)
{
switch (tokens[tokenIndex])
{
case "lz": case "l0": case "128": encoding |= VexOpcodeEncoding.VectorLength_0; break;
case "l1": case "256": encoding |= VexOpcodeEncoding.VectorLength_1; break;
case "512": encoding |= VexOpcodeEncoding.VectorLength_2; break;
case "lig": encoding |= VexOpcodeEncoding.VectorLength_Ignored; break;
default: encoding |= VexOpcodeEncoding.VectorLength_Ignored; return;
}
++tokenIndex;
}
private static void ParseVex_Vvvv(ref VexOpcodeEncoding encoding, string[] tokens, ref int tokenIndex)
{
switch (tokens[tokenIndex])
{
case "nds": encoding |= VexOpcodeEncoding.NonDestructiveReg_Source; break;
case "ndd": encoding |= VexOpcodeEncoding.NonDestructiveReg_Dest; break;
case "dds": encoding |= VexOpcodeEncoding.NonDestructiveReg_SecondSource; break;
default: encoding |= VexOpcodeEncoding.NonDestructiveReg_Invalid; return;
}
++tokenIndex;
}
