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diff --git a/hook/src/x86.zig b/hook/src/x86.zig
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@@ -0,0 +1,670 @@
+const std = @import("std");
+const testing = std.testing;
+
+const makeHex = @import("utils.zig").makeHex;
+
+pub const Opcode = struct {
+ pub const Prefixes = struct {
+ pub const es = 0x26;
+ pub const cs = 0x2E;
+ pub const ss = 0x36;
+ pub const ds = 0x3E;
+ pub const fs = 0x64;
+ pub const gs = 0x65;
+ pub const opsz = 0x66;
+ pub const adsz = 0x67;
+ pub const lock = 0xF0;
+ pub const repn = 0xF2;
+ pub const rep = 0xF3;
+ };
+
+ pub const Op1No = struct {
+ pub const pushes = 0x06;
+ pub const popes = 0x07;
+ pub const pushcs = 0x0E;
+ pub const pushss = 0x16;
+ pub const popss = 0x17;
+ pub const pushds = 0x1E;
+ pub const popds = 0x1F;
+ pub const daa = 0x27;
+ pub const das = 0x2F;
+ pub const aaa = 0x37;
+ pub const aas = 0x3F;
+ pub const inceax = 0x40;
+ pub const incecx = 0x41;
+ pub const incedx = 0x42;
+ pub const incebx = 0x43;
+ pub const incesp = 0x44;
+ pub const incebp = 0x45;
+ pub const incesi = 0x46;
+ pub const incedi = 0x47;
+ pub const deceax = 0x48;
+ pub const dececx = 0x49;
+ pub const decedx = 0x4A;
+ pub const decebx = 0x4B;
+ pub const decesp = 0x4C;
+ pub const decebp = 0x4D;
+ pub const decesi = 0x4E;
+ pub const decedi = 0x4F;
+ pub const pusheax = 0x50;
+ pub const pushecx = 0x51;
+ pub const pushedx = 0x52;
+ pub const pushebx = 0x53;
+ pub const pushesp = 0x54;
+ pub const pushebp = 0x55;
+ pub const pushesi = 0x56;
+ pub const pushedi = 0x57;
+ pub const popeax = 0x58;
+ pub const popecx = 0x59;
+ pub const popedx = 0x5A;
+ pub const popebx = 0x5B;
+ pub const popesp = 0x5C;
+ pub const popebp = 0x5D;
+ pub const popesi = 0x5E;
+ pub const popedi = 0x5F;
+ pub const pusha = 0x60;
+ pub const popa = 0x61;
+ pub const nop = 0x90;
+ pub const xchgecxeax = 0x91;
+ pub const xchgedxeax = 0x92;
+ pub const xchgebxeax = 0x93;
+ pub const xchgespeax = 0x94;
+ pub const xchgebpeax = 0x95;
+ pub const xchgesieax = 0x96;
+ pub const xchgedieax = 0x97;
+ pub const cwde = 0x98;
+ pub const cdq = 0x99;
+ pub const wait = 0x9B;
+ pub const pushf = 0x9C;
+ pub const popf = 0x9D;
+ pub const sahf = 0x9E;
+ pub const lahf = 0x9F;
+ pub const movs8 = 0xA4;
+ pub const movsw = 0xA5;
+ pub const cmps8 = 0xA6;
+ pub const cmpsw = 0xA7;
+ pub const stos8 = 0xAA;
+ pub const stosd = 0xAB;
+ pub const lods8 = 0xAC;
+ pub const lodsd = 0xAD;
+ pub const scas8 = 0xAE;
+ pub const scasd = 0xAF;
+ pub const ret = 0xC3;
+ pub const leave = 0xC9;
+ pub const retf = 0xCB;
+ pub const int3 = 0xCC;
+ pub const into = 0xCE;
+ pub const xlat = 0xD7;
+ pub const cmc = 0xF5;
+ pub const clc = 0xF8;
+ pub const stc = 0xF9;
+ pub const cli = 0xFA;
+ pub const sti = 0xFB;
+ pub const cld = 0xFC;
+ pub const std = 0xFD;
+ };
+ pub const Op1I8 = struct {
+ pub const addali = 0x04;
+ pub const orali = 0x0C;
+ pub const adcali = 0x14;
+ pub const sbbali = 0x1C;
+ pub const andali = 0x24;
+ pub const subali = 0x2C;
+ pub const xorali = 0x34;
+ pub const cmpali = 0x3C;
+ pub const pushi8 = 0x6A;
+ pub const testali = 0xA8;
+ pub const jo = 0x70;
+ pub const jno = 0x71;
+ pub const jb = 0x72;
+ pub const jnb = 0x73;
+ pub const jz = 0x74;
+ pub const jnz = 0x75;
+ pub const jna = 0x76;
+ pub const ja = 0x77;
+ pub const js = 0x78;
+ pub const jns = 0x79;
+ pub const jp = 0x7A;
+ pub const jnp = 0x7B;
+ pub const jl = 0x7C;
+ pub const jnl = 0x7D;
+ pub const jng = 0x7E;
+ pub const jg = 0x7F;
+ pub const movali = 0xB0;
+ pub const movcli = 0xB1;
+ pub const movdli = 0xB2;
+ pub const movbli = 0xB3;
+ pub const movahi = 0xB4;
+ pub const movchi = 0xB5;
+ pub const movdhi = 0xB6;
+ pub const movbhi = 0xB7;
+ pub const int = 0xCD;
+ pub const amx = 0xD4;
+ pub const adx = 0xD5;
+ pub const loopnz = 0xE0;
+ pub const loopz = 0xE1;
+ pub const loop = 0xE2;
+ pub const jcxz = 0xE3;
+ pub const jmpi8 = 0xEB;
+ };
+ pub const Op1IW = struct {
+ pub const addeaxi = 0x05;
+ pub const oreaxi = 0x0D;
+ pub const adceaxi = 0x15;
+ pub const sbbeaxi = 0x1D;
+ pub const andeaxi = 0x25;
+ pub const subeaxi = 0x2D;
+ pub const xoreaxi = 0x35;
+ pub const cmpeaxi = 0x3D;
+ pub const pushiw = 0x68;
+ pub const testeaxi = 0xA9;
+ pub const moveaxi = 0xB8;
+ pub const movecxi = 0xB9;
+ pub const movedxi = 0xBA;
+ pub const movebxi = 0xBB;
+ pub const movespi = 0xBC;
+ pub const movebpi = 0xBD;
+ pub const movesii = 0xBE;
+ pub const movedii = 0xBF;
+ pub const call = 0xE8;
+ pub const jmpiw = 0xE9;
+ };
+ pub const Op1IWI = struct {
+ pub const movalii = 0xA0;
+ pub const moveaxii = 0xA1;
+ pub const moviial = 0xA2;
+ pub const moviieax = 0xA3;
+ };
+ pub const Op1I16 = struct {
+ pub const reti16 = 0xC2;
+ pub const retfi16 = 0xCA;
+ };
+ pub const Op1Mrm = struct {
+ pub const addmr8 = 0x00;
+ pub const addmrw = 0x01;
+ pub const addrm8 = 0x02;
+ pub const addrmw = 0x03;
+ pub const ormr8 = 0x08;
+ pub const ormrw = 0x09;
+ pub const orrm8 = 0x0A;
+ pub const orrmw = 0x0B;
+ pub const adcmr8 = 0x10;
+ pub const adcmrw = 0x11;
+ pub const adcrm8 = 0x12;
+ pub const adcrmw = 0x13;
+ pub const sbbmr8 = 0x18;
+ pub const sbbmrw = 0x19;
+ pub const sbbrm8 = 0x1A;
+ pub const sbbrmw = 0x1B;
+ pub const andmr8 = 0x20;
+ pub const andmrw = 0x21;
+ pub const andrm8 = 0x22;
+ pub const andrmw = 0x23;
+ pub const submr8 = 0x28;
+ pub const submrw = 0x29;
+ pub const subrm8 = 0x2A;
+ pub const subrmw = 0x2B;
+ pub const xormr8 = 0x30;
+ pub const xormrw = 0x31;
+ pub const xorrm8 = 0x32;
+ pub const xorrmw = 0x33;
+ pub const cmpmr8 = 0x38;
+ pub const cmpmrw = 0x39;
+ pub const cmprm8 = 0x3A;
+ pub const cmprmw = 0x3B;
+ pub const arpl = 0x63;
+ pub const testmr8 = 0x84;
+ pub const testmrw = 0x85;
+ pub const xchgmr8 = 0x86;
+ pub const xchgmrw = 0x87;
+ pub const movmr8 = 0x88;
+ pub const movmrw = 0x89;
+ pub const movrm8 = 0x8A;
+ pub const movrmw = 0x8B;
+ pub const movms = 0x8C;
+ pub const lea = 0x8D;
+ pub const movsm = 0x8E;
+ pub const popm = 0x8F;
+ pub const shiftm18 = 0xD0;
+ pub const shiftm1w = 0xD1;
+ pub const shiftmcl8 = 0xD2;
+ pub const shiftmclw = 0xD3;
+ pub const fltblk1 = 0xD8;
+ pub const fltblk2 = 0xD9;
+ pub const fltblk3 = 0xDA;
+ pub const fltblk4 = 0xDB;
+ pub const fltblk5 = 0xDC;
+ pub const fltblk6 = 0xDD;
+ pub const fltblk7 = 0xDE;
+ pub const fltblk8 = 0xDF;
+ pub const miscm8 = 0xFE;
+ pub const miscmw = 0xFF;
+ };
+ pub const Op1MrmI8 = struct {
+ pub const imulmi8 = 0x6B;
+ pub const alumi8 = 0x80;
+ pub const alumi8x = 0x82;
+ pub const alumi8s = 0x83;
+ pub const shiftmi8 = 0xC0;
+ pub const shiftmiw = 0xC1;
+ pub const movmi8 = 0xC6;
+ };
+ pub const Op1MrmIW = struct {
+ pub const imulmiw = 0x69;
+ pub const alumiw = 0x81;
+ pub const movmiw = 0xC7;
+ };
+
+ pub const Op1Extra = struct {
+ const enter = 0xC8;
+ const crazy8 = 0xF6;
+ const crazyw = 0xF7;
+ };
+
+ pub const Op2No = struct {
+ pub const rdtsc = 0x31;
+ pub const rdpmd = 0x33;
+ pub const sysenter = 0x34;
+ pub const pushfs = 0xA0;
+ pub const popfs = 0xA1;
+ pub const cpuid = 0xA2;
+ pub const pushgs = 0xA8;
+ pub const popgs = 0xA9;
+ pub const rsm = 0xAA;
+ pub const bswapeax = 0xC8;
+ pub const bswapecx = 0xC9;
+ pub const bswapedx = 0xCA;
+ pub const bswapebx = 0xCB;
+ pub const bswapesp = 0xCC;
+ pub const bswapebp = 0xCD;
+ pub const bswapesi = 0xCE;
+ pub const bswapedi = 0xCF;
+ pub const emms = 0x77;
+ };
+ pub const Op2IW = struct {
+ pub const joii = 0x80;
+ pub const jnoii = 0x81;
+ pub const jbii = 0x82;
+ pub const jnbii = 0x83;
+ pub const jzii = 0x84;
+ pub const jnzii = 0x85;
+ pub const jnaii = 0x86;
+ pub const jaii = 0x87;
+ pub const jsii = 0x88;
+ pub const jnsii = 0x89;
+ pub const jpii = 0x8A;
+ pub const jnpii = 0x8B;
+ pub const jlii = 0x8C;
+ pub const jnlii = 0x8D;
+ pub const jngii = 0x8E;
+ pub const jgii = 0x8F;
+ };
+ pub const Op2Mrm = struct {
+ pub const nop = 0x0D;
+ pub const hints1 = 0x18;
+ pub const hints2 = 0x19;
+ pub const hints3 = 0x1A;
+ pub const hints4 = 0x1B;
+ pub const hints5 = 0x1C;
+ pub const hints6 = 0x1D;
+ pub const hints7 = 0x1E;
+ pub const hints8 = 0x1F;
+ pub const cmovo = 0x40;
+ pub const cmovno = 0x41;
+ pub const cmovb = 0x42;
+ pub const cmovnb = 0x43;
+ pub const cmovz = 0x44;
+ pub const cmovnz = 0x45;
+ pub const cmovna = 0x46;
+ pub const cmova = 0x47;
+ pub const cmovs = 0x48;
+ pub const cmovns = 0x49;
+ pub const cmovp = 0x4A;
+ pub const cmovnp = 0x4B;
+ pub const cmovl = 0x4C;
+ pub const cmovnl = 0x4D;
+ pub const cmovng = 0x4E;
+ pub const cmovg = 0x4F;
+ pub const seto = 0x90;
+ pub const setno = 0x91;
+ pub const setb = 0x92;
+ pub const setnb = 0x93;
+ pub const setz = 0x94;
+ pub const setnz = 0x95;
+ pub const setna = 0x96;
+ pub const seta = 0x97;
+ pub const sets = 0x98;
+ pub const setns = 0x99;
+ pub const setp = 0x9A;
+ pub const setnp = 0x9B;
+ pub const setl = 0x9C;
+ pub const setnl = 0x9D;
+ pub const setng = 0x9E;
+ pub const setg = 0x9F;
+ pub const btmr = 0xA3;
+ pub const shldmrcl = 0xA5;
+ pub const bts = 0xAB;
+ pub const shrdmrcl = 0xAD;
+ pub const misc = 0xAE;
+ pub const imul = 0xAF;
+ pub const cmpxchg8 = 0xB0;
+ pub const cmpxchgw = 0xB1;
+ pub const movzx8 = 0xB6;
+ pub const movzxw = 0xB7;
+ pub const popcnt = 0xB8;
+ pub const btcrm = 0xBB;
+ pub const bsf = 0xBC;
+ pub const bsr = 0xBD;
+ pub const movsx8 = 0xBE;
+ pub const movsxw = 0xBF;
+ pub const xaddrm8 = 0xC0;
+ pub const xaddrmw = 0xC1;
+ pub const cmpxchg64 = 0xC7;
+ pub const movrm128 = 0x10;
+ pub const movmr128 = 0x11;
+ pub const movlrm = 0x12;
+ pub const movlmr = 0x13;
+ pub const unpckl = 0x14;
+ pub const unpckh = 0x15;
+ pub const movhrm = 0x16;
+ pub const movhmr = 0x17;
+ pub const movarm = 0x28;
+ pub const movamr = 0x29;
+ pub const cvtif64 = 0x2A;
+ pub const movnt = 0x2B;
+ pub const cvtft64 = 0x2C;
+ pub const cvtfi64 = 0x2D;
+ pub const ucomi = 0x2E;
+ pub const comi = 0x2F;
+ pub const movmsk = 0x50;
+ pub const sqrt = 0x51;
+ pub const rsqrt = 0x52;
+ pub const rcp = 0x53;
+ pub const and_ = 0x54;
+ pub const andn = 0x55;
+ pub const or_ = 0x56;
+ pub const xor = 0x57;
+ pub const add = 0x58;
+ pub const mul = 0x59;
+ pub const cvtff128 = 0x5A;
+ pub const cvtfi128 = 0x5B;
+ pub const sub = 0x5C;
+ pub const div = 0x5D;
+ pub const min = 0x5E;
+ pub const max = 0x5F;
+ pub const punpcklbw = 0x60;
+ pub const punpcklbd = 0x61;
+ pub const punpckldq = 0x62;
+ pub const packsswb = 0x63;
+ pub const pcmpgtb = 0x64;
+ pub const pcmpgtw = 0x65;
+ pub const pcmpgtd = 0x66;
+ pub const packuswb = 0x67;
+ pub const punpckhbw = 0x68;
+ pub const punpckhwd = 0x69;
+ pub const punpckhdq = 0x6A;
+ pub const packssdw = 0x6B;
+ pub const punpcklqdq = 0x6C;
+ pub const punpckhqdq = 0x6D;
+ pub const movdrm = 0x6E;
+ pub const movqrm = 0x6F;
+ pub const pcmpeqb = 0x74;
+ pub const pcmpeqw = 0x75;
+ pub const pcmpeqd = 0x76;
+ pub const movdmr = 0x7E;
+ pub const movqmr = 0x7F;
+ pub const movnti = 0xC3;
+ pub const addsub = 0xD0;
+ pub const psrlw = 0xD1;
+ pub const psrld = 0xD2;
+ pub const psrlq = 0xD3;
+ pub const paddq = 0xD4;
+ pub const pmullw = 0xD5;
+ pub const movqrr = 0xD6;
+ pub const pmovmskb = 0xD7;
+ pub const psubusb = 0xD8;
+ pub const psubusw = 0xD9;
+ pub const pminub = 0xDA;
+ pub const pand = 0xDB;
+ pub const paddusb = 0xDC;
+ pub const paddusw = 0xDD;
+ pub const pmaxub = 0xDE;
+ pub const pandn = 0xDF;
+ pub const pavgb = 0xE0;
+ pub const psraw = 0xE1;
+ pub const psrad = 0xE2;
+ pub const pavgw = 0xE3;
+ pub const pmulhuw = 0xE4;
+ pub const pmulhw = 0xE5;
+ pub const cvtq = 0xE6;
+ pub const movntq = 0xE7;
+ pub const psubsb = 0xE8;
+ pub const psubsw = 0xE9;
+ pub const pminsb = 0xEA;
+ pub const pminsw = 0xEB;
+ pub const paddsb = 0xEC;
+ pub const paddsw = 0xED;
+ pub const pmaxsw = 0xEE;
+ pub const pxor = 0xEF;
+ pub const lddqu = 0xF0;
+ pub const psllw = 0xF1;
+ pub const pslld = 0xF2;
+ pub const psllq = 0xF3;
+ pub const pmuludq = 0xF4;
+ pub const pmaddwd = 0xF5;
+ pub const psabdw = 0xF6;
+ pub const maskmovq = 0xF7;
+ pub const psubb = 0xF8;
+ pub const psubw = 0xF9;
+ pub const psubd = 0xFA;
+ pub const psubq = 0xFB;
+ pub const paddb = 0xFC;
+ pub const paddw = 0xFD;
+ pub const paddd = 0xFE;
+ };
+ pub const Op2MrmI8 = struct {
+ pub const shldmri = 0xA4;
+ pub const shrdmri = 0xAC;
+ pub const btxmi = 0xBA;
+ pub const pshuf = 0x70;
+ pub const pswi = 0x71;
+ pub const psdi = 0x72;
+ pub const psqi = 0x73;
+ pub const cmpsi = 0xC2;
+ pub const pinsrw = 0xC4;
+ pub const pextrw = 0xC5;
+ pub const shuf = 0xC6;
+ };
+
+ pub const op2_byte = 0x0F;
+ pub const op3_1 = 0x38;
+ pub const op3_2 = 0x3A;
+ pub const op3dnow = 0x0F;
+};
+
+// Constructs a ModRM byte
+pub fn modrm(mod: u8, reg: u8, rm: u8) u8 {
+ return mod << 6 | reg << 3 | rm;
+}
+
+fn mrmsib(b: [*]const u8, address_len: usize) usize {
+ if (address_len == 4 or b[0] & 0xC0 != 0) {
+ const sib: usize = if (address_len == 4 and b[0] < 0xC0 and (b[0] & 7) == 4) 1 else 0;
+ if ((b[0] & 0xC0) == 0x40) {
+ return 2 + sib;
+ }
+ if ((b[0] & 0xC0) == 0x00) {
+ if ((b[0] & 7) != 5) {
+ if (sib == 1 and (b[1] & 7) == 5) {
+ return if (b[0] & 0x40 != 0) 3 else 6;
+ }
+ return 1 + sib;
+ }
+ return 1 + address_len + sib;
+ }
+ if ((b[0] & 0xC0) == 0x80) {
+ return 1 + address_len + sib;
+ }
+ }
+ if (address_len == 2 and (b[0] & 0xC7) == 0x06) {
+ return 3;
+ }
+ return 1;
+}
+
+fn is_field(comptime T: type, byte: u8) bool {
+ @setEvalBranchQuota(100000);
+ for (@typeInfo(T).@"struct".decls) |decl| {
+ const decl_ptr = &@field(T, decl.name);
+ if (decl_ptr.* == byte) {
+ return true;
+ }
+ }
+ return false;
+}
+
+pub fn x86_len(address: [*]const u8) !usize {
+ var b = address;
+
+ var prefix_len: usize = 0;
+ var operand_len: usize = 4;
+ var address_len: usize = 4;
+
+ // prefixes
+ while (prefix_len < 14 and switch (b[0]) {
+ inline 0x00...0xFF => |byte| blk: {
+ break :blk comptime is_field(Opcode.Prefixes, byte);
+ },
+ }) : ({
+ prefix_len += 1;
+ b += 1;
+ }) {
+ if (b[0] == Opcode.Prefixes.opsz) {
+ operand_len = 2;
+ } else if (b[0] == Opcode.Prefixes.adsz) {
+ address_len = 2;
+ }
+ }
+
+ // opcode
+ return switch (b[0]) {
+ Opcode.op2_byte => switch (b[1]) {
+ Opcode.op3_1,
+ Opcode.op3_2,
+ Opcode.op3dnow,
+ => error.UnsupportedInstruction,
+ inline else => |byte| blk: {
+ if (comptime is_field(Opcode.Op2No, byte)) {
+ break :blk prefix_len + 2;
+ }
+ if (comptime is_field(Opcode.Op2IW, byte)) {
+ break :blk prefix_len + 2 + operand_len;
+ }
+ if (comptime is_field(Opcode.Op2Mrm, byte)) {
+ break :blk prefix_len + 2 + mrmsib(b + 2, address_len);
+ }
+ if (comptime is_field(Opcode.Op2MrmI8, byte)) {
+ operand_len = 1;
+ break :blk prefix_len + 2 + operand_len + mrmsib(b + 2, address_len);
+ }
+ break :blk error.UnsupportedInstruction;
+ },
+ },
+ inline else => |byte| blk: {
+ if (comptime is_field(Opcode.Op1No, byte)) {
+ break :blk prefix_len + 1;
+ }
+ if (comptime is_field(Opcode.Op1I8, byte)) {
+ operand_len = 1;
+ break :blk prefix_len + 1 + operand_len;
+ }
+ if (comptime is_field(Opcode.Op1IW, byte)) {
+ break :blk prefix_len + 1 + operand_len;
+ }
+ if (comptime is_field(Opcode.Op1IWI, byte)) {
+ break :blk prefix_len + 1 + address_len;
+ }
+ if (comptime is_field(Opcode.Op1I16, byte)) {
+ break :blk prefix_len + 3;
+ }
+ if (comptime is_field(Opcode.Op1Mrm, byte)) {
+ break :blk prefix_len + 1 + mrmsib(b + 1, address_len);
+ }
+ if (comptime is_field(Opcode.Op1MrmI8, byte)) {
+ operand_len = 1;
+ break :blk prefix_len + 1 + operand_len + mrmsib(b + 1, address_len);
+ }
+ if (comptime is_field(Opcode.Op1MrmIW, byte)) {
+ break :blk prefix_len + 1 + operand_len + mrmsib(b + 1, address_len);
+ }
+ if (byte == Opcode.Op1Extra.enter) {
+ break :blk prefix_len + 4;
+ }
+ if (byte == Opcode.Op1Extra.crazy8 or byte == Opcode.Op1Extra.crazyw) {
+ if (byte == Opcode.Op1Extra.crazy8) {
+ operand_len = 1;
+ }
+
+ if ((b[1] & 0x38) >= 0x10) {
+ operand_len = 0;
+ }
+
+ break :blk prefix_len + 1 + operand_len + mrmsib(b + 1, address_len);
+ }
+ break :blk error.UnsupportedInstruction;
+ },
+ };
+}
+
+test "Simple x86 instruction lengths" {
+ const nop = makeHex("90");
+ try testing.expectEqual(1, try x86_len(nop.ptr));
+ const push_eax = makeHex("50");
+ try testing.expectEqual(1, try x86_len(push_eax.ptr));
+ const mov_eax = makeHex("B8 78 56 34 12");
+ try testing.expectEqual(5, try x86_len(mov_eax.ptr));
+ const add_mem_eax = makeHex("00 00");
+ try testing.expectEqual(2, try x86_len(add_mem_eax.ptr));
+ const mov_ax = makeHex("66 B8 34 12");
+ try testing.expectEqual(4, try x86_len(mov_ax.ptr));
+ const add_mem_disp32 = makeHex("00 80 78 56 34 12");
+ try testing.expectEqual(6, try x86_len(add_mem_disp32.ptr));
+ const add_eax_imm = makeHex("05 78 56 34 12");
+ try testing.expectEqual(5, try x86_len(add_eax_imm.ptr));
+}
+
+test "The \"crazy\" instructions should be given correct lengths" {
+ const test8 = makeHex("F6 05 12 34 56 78 12");
+ try testing.expectEqual(7, try x86_len(test8.ptr));
+ const test16 = makeHex("66 F7 05 12 34 56 78 12");
+ try testing.expectEqual(9, try x86_len(test16.ptr));
+ const test32 = makeHex("F7 05 12 34 56 78 12 34 56 78");
+ try testing.expectEqual(10, try x86_len(test32.ptr));
+ const not8 = makeHex("F6 15 12 34 56 78");
+ try testing.expectEqual(6, try x86_len(not8.ptr));
+ const not16 = makeHex("66 F7 15 12 34 56 78");
+ try testing.expectEqual(7, try x86_len(not16.ptr));
+ const not32 = makeHex("F7 15 12 34 56 78");
+ try testing.expectEqual(6, try x86_len(not32.ptr));
+}
+
+test "SIB bytes should be decoded correctly" {
+ const fstp = makeHex("D9 1C 24");
+ try testing.expectEqual(3, try x86_len(fstp.ptr));
+}
+
+test "mov AL, moff8 instructions should be decoded correctly" {
+ const mov_moff8_al = makeHex("A2 DA 78 B4 0D");
+ try testing.expectEqual(5, try x86_len(mov_moff8_al.ptr));
+ const mov_al_moff8 = makeHex("A0 28 DF 5C 66");
+ try testing.expectEqual(5, try x86_len(mov_al_moff8.ptr));
+}
+
+test "16-bit MRM instructions should be decoded correctly" {
+ const fiadd_off16 = makeHex("67 DA 06 DF 11");
+ try testing.expectEqual(5, try x86_len(fiadd_off16.ptr));
+ const fld_tword = makeHex("67 DB 2E 99 C4");
+ try testing.expectEqual(5, try x86_len(fld_tword.ptr));
+ const add_off16_bl = makeHex("67 00 1E F5 BB");
+ try testing.expectEqual(5, try x86_len(add_off16_bl.ptr));
+}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2025-08-16 09:35:04 +0000