Initial commit

2026-10-15 05:58:22 +00:00 · 2026-05-31 01:09:34 +01:00
commit 1d51b29b92
31 changed files with 4874 additions and 0 deletions
@@ -0,0 +1,146 @@
+package vm
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+type Opcode byte
+
+const (
+	OpNop   Opcode = 0x00
+	OpPush  Opcode = 0x01
+	OpPop   Opcode = 0x02
+	OpDup   Opcode = 0x03
+	OpAdd   Opcode = 0x04
+	OpSub   Opcode = 0x05
+	OpMul   Opcode = 0x06
+	OpDiv   Opcode = 0x07
+	OpMod   Opcode = 0x08
+	OpXor   Opcode = 0x09
+	OpAnd   Opcode = 0x0A
+	OpOr    Opcode = 0x0B
+	OpNot   Opcode = 0x0C
+	OpShl   Opcode = 0x0D
+	OpShr   Opcode = 0x0E
+	OpCmpEq Opcode = 0x0F
+	OpCmpLt Opcode = 0x10
+	OpCmpGt Opcode = 0x11
+	OpJmp   Opcode = 0x12
+	OpJz    Opcode = 0x13
+	OpJnz   Opcode = 0x14
+	OpLoad  Opcode = 0x15
+	OpStore Opcode = 0x16
+	OpCall  Opcode = 0x17
+	OpRet   Opcode = 0x18
+	OpHalt  Opcode = 0x19
+	OpSwap  Opcode = 0x1A
+	OpRot   Opcode = 0x1B
+	opJunkA Opcode = 0x1C
+	opJunkB Opcode = 0x1D
+	opJunkC Opcode = 0x1E
+	opJunkD Opcode = 0x1F
+)
+
+const dispatchKey byte = 0xA5
+
+var opcodeNames = map[Opcode]string{
+	OpNop: "NOP", OpPush: "PUSH", OpPop: "POP", OpDup: "DUP",
+	OpAdd: "ADD", OpSub: "SUB", OpMul: "MUL", OpDiv: "DIV",
+	OpMod: "MOD", OpXor: "XOR", OpAnd: "AND", OpOr: "OR",
+	OpNot: "NOT", OpShl: "SHL", OpShr: "SHR", OpCmpEq: "CMP_EQ",
+	OpCmpLt: "CMP_LT", OpCmpGt: "CMP_GT", OpJmp: "JMP", OpJz: "JZ",
+	OpJnz: "JNZ", OpLoad: "LOAD", OpStore: "STORE", OpCall: "CALL",
+	OpRet: "RET", OpHalt: "HALT", OpSwap: "SWAP", OpRot: "ROT",
+}
+
+func (o Opcode) String() string {
+	if name, ok := opcodeNames[o]; ok {
+		return name
+	}
+	return fmt.Sprintf("UNK(0x%02X)", byte(o))
+}
+
+func encodeOp(op Opcode) byte {
+	return byte(op) ^ dispatchKey
+}
+
+func decodeOp(b byte) Opcode {
+	return Opcode(b ^ dispatchKey)
+}
+
+type argEncoding int
+
+const (
+	argNone argEncoding = iota
+	argI8
+	argI16
+	argI32
+	argI64
+)
+
+func opArgEnc(op Opcode) argEncoding {
+	switch op {
+	case OpPush:
+		return argI64
+	case OpShl, OpShr, OpSwap:
+		return argI8
+	case OpJmp, OpJz, OpJnz:
+		return argI32
+	case OpLoad, OpStore, OpCall:
+		return argI16
+	default:
+		return argNone
+	}
+}
+
+func InstrSize(op Opcode) int {
+	switch opArgEnc(op) {
+	case argI64:
+		return 9
+	case argI32:
+		return 5
+	case argI16:
+		return 3
+	case argI8:
+		return 2
+	default:
+		return 1
+	}
+}
+
+func EncodeInstr(op Opcode, arg int64) []byte {
+	size := InstrSize(op)
+	buf := make([]byte, size)
+	buf[0] = encodeOp(op)
+
+	switch opArgEnc(op) {
+	case argI64:
+		binary.LittleEndian.PutUint64(buf[1:], uint64(arg))
+	case argI32:
+		binary.LittleEndian.PutUint32(buf[1:], uint32(arg))
+	case argI16:
+		binary.LittleEndian.PutUint16(buf[1:], uint16(arg))
+	case argI8:
+		buf[1] = byte(arg)
+	}
+	return buf
+}
+
+func DecodeInstr(code []byte, pc int) (Opcode, int64, int) {
+	op := decodeOp(code[pc])
+	size := InstrSize(op)
+
+	var arg int64
+	switch opArgEnc(op) {
+	case argI64:
+		arg = int64(binary.LittleEndian.Uint64(code[pc+1 : pc+9]))
+	case argI32:
+		arg = int64(binary.LittleEndian.Uint32(code[pc+1 : pc+5]))
+	case argI16:
+		arg = int64(binary.LittleEndian.Uint16(code[pc+1 : pc+3]))
+	case argI8:
+		arg = int64(code[pc+1])
+	}
+	return op, arg, size
+}