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pre { line-height: 125%; }
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span.linenos { color: inherit; background-color: transparent; padding-left: 5px; padding-right: 5px; }
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span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
.highlight .hll { background-color: #ffffcc }
.highlight .c { color: #888888 } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { color: #008800; font-weight: bold } /* Keyword */
.highlight .ch { color: #888888 } /* Comment.Hashbang */
.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #666666 } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */
.highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */
.highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */
.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
.highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */
.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
.highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */
.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
DEFAULT mu

LABEL mu
        LINUX /boot/kernel.xz
        APPEND vga=nomodeset
        INITRD /boot/rootfs.xz
n191' href='#n191'>191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691
//: Since we're tagging operands with their types, let's start checking these
//: operand types for each instruction.

void test_check_missing_imm8_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "cd\n"  // interrupt ??
  );
  CHECK_TRACE_CONTENTS(
      "error: 'cd' (software interrupt): missing imm8 operand\n"
  );
}

:(before "Pack Operands(segment code)")
check_operands(code);
if (trace_contains_errors()) return;

:(code)
void check_operands(const segment& code) {
  trace(3, "transform") << "-- check operands" << end();
  for (int i = 0;  i < SIZE(code.lines);  ++i) {
    check_operands(code.lines.at(i));
    if (trace_contains_errors()) return;  // stop at the first mal-formed instruction
  }
}

void check_operands(const line& inst) {
  word op = preprocess_op(inst.words.at(0));
  if (op.data == "0f") {
    check_operands_0f(inst);
    return;
  }
  if (op.data == "f3") {
    check_operands_f3(inst);
    return;
  }
  check_operands(inst, op);
}

word preprocess_op(word/*copy*/ op) {
  op.data = tolower(op.data.c_str());
  // opcodes can't be negative
  if (starts_with(op.data, "0x"))
    op.data = op.data.substr(2);
  if (SIZE(op.data) == 1)
    op.data = string("0")+op.data;
  return op;
}

void test_preprocess_op() {
  word w1;  w1.data = "0xf";
  word w2;  w2.data = "0f";
  CHECK_EQ(preprocess_op(w1).data, preprocess_op(w2).data);
}

//: To check the operands for an opcode, we'll track the permitted operands
//: for each supported opcode in a bitvector. That way we can often compute the
//: 'received' operand bitvector for each instruction's operands and compare
//: it with the 'expected' bitvector.
//:
//: The 'expected' and 'received' bitvectors can be different; the MODRM bit
//: in the 'expected' bitvector maps to multiple 'received' operand types in
//: an instruction. We deal in expected bitvectors throughout.

:(before "End Types")
enum expected_operand_type {
  // start from the least significant bit
  MODRM,  // more complex, may also involve disp8 or disp32
  SUBOP,
  DISP8,
  DISP16,
  DISP32,
  IMM8,
  IMM32,
  NUM_OPERAND_TYPES
};
:(before "End Globals")
vector<string> Operand_type_name;
map<string, expected_operand_type> Operand_type;
:(before "End One-time Setup")
init_op_types();
:(code)
void init_op_types() {
  assert(NUM_OPERAND_TYPES <= /*bits in a uint8_t*/8);
  Operand_type_name.resize(NUM_OPERAND_TYPES);
  #define DEF(type) Operand_type_name.at(type) = tolower(#type), put(Operand_type, tolower(#type), type);
  DEF(MODRM);
  DEF(SUBOP);
  DEF(DISP8);
  DEF(DISP16);
  DEF(DISP32);
  DEF(IMM8);
  DEF(IMM32);
  #undef DEF
}

:(before "End Globals")
map</*op*/string, /*bitvector*/uint8_t> Permitted_operands;
const uint8_t INVALID_OPERANDS = 0xff;  // no instruction uses all the operand types
:(before "End One-time Setup")
init_permitted_operands();
:(code)
void init_permitted_operands() {
  //// Class A: just op, no operands
  // halt
  put(Permitted_operands, "f4", 0x00);
  // inc
  put(Permitted_operands, "40", 0x00);
  put(Permitted_operands, "41", 0x00);
  put(Permitted_operands, "42", 0x00);
  put(Permitted_operands, "43", 0x00);
  put(Permitted_operands, "44", 0x00);
  put(Permitted_operands, "45", 0x00);
  put(Permitted_operands, "46", 0x00);
  put(Permitted_operands, "47", 0x00);
  // dec
  put(Permitted_operands, "48", 0x00);
  put(Permitted_operands, "49", 0x00);
  put(Permitted_operands, "4a", 0x00);
  put(Permitted_operands, "4b", 0x00);
  put(Permitted_operands, "4c", 0x00);
  put(Permitted_operands, "4d", 0x00);
  put(Permitted_operands, "4e", 0x00);
  put(Permitted_operands, "4f", 0x00);
  // push
  put(Permitted_operands, "50", 0x00);
  put(Permitted_operands, "51", 0x00);
  put(Permitted_operands, "52", 0x00);
  put(Permitted_operands, "53", 0x00);
  put(Permitted_operands, "54", 0x00);
  put(Permitted_operands, "55", 0x00);
  put(Permitted_operands, "56", 0x00);
  put(Permitted_operands, "57", 0x00);
  // pop
  put(Permitted_operands, "58", 0x00);
  put(Permitted_operands, "59", 0x00);
  put(Permitted_operands, "5a", 0x00);
  put(Permitted_operands, "5b", 0x00);
  put(Permitted_operands, "5c", 0x00);
  put(Permitted_operands, "5d", 0x00);
  put(Permitted_operands, "5e", 0x00);
  put(Permitted_operands, "5f", 0x00);
  // sign-extend EAX into EDX
  put(Permitted_operands, "99", 0x00);
  // return
  put(Permitted_operands, "c3", 0x00);

  //// Class B: just op and disp8
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     0     0      |0       1     0     0

  // jump
  put(Permitted_operands, "eb", 0x04);
  put(Permitted_operands, "72", 0x04);
  put(Permitted_operands, "73", 0x04);
  put(Permitted_operands, "74", 0x04);
  put(Permitted_operands, "75", 0x04);
  put(Permitted_operands, "76", 0x04);
  put(Permitted_operands, "77", 0x04);
  put(Permitted_operands, "7c", 0x04);
  put(Permitted_operands, "7d", 0x04);
  put(Permitted_operands, "7e", 0x04);
  put(Permitted_operands, "7f", 0x04);

  //// Class D: just op and disp32
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     0     1      |0       0     0     0
  put(Permitted_operands, "e8", 0x10);  // call
  put(Permitted_operands, "e9", 0x10);  // jump

  //// Class E: just op and imm8
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     1     0      |0       0     0     0
  put(Permitted_operands, "cd", 0x20);  // software interrupt

  //// Class F: just op and imm32
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  1     0     0      |0       0     0     0
  put(Permitted_operands, "05", 0x40);  // add
  put(Permitted_operands, "2d", 0x40);  // subtract
  put(Permitted_operands, "25", 0x40);  // and
  put(Permitted_operands, "0d", 0x40);  // or
  put(Permitted_operands, "35", 0x40);  // xor
  put(Permitted_operands, "3d", 0x40);  // compare
  put(Permitted_operands, "68", 0x40);  // push
  // copy
  put(Permitted_operands, "b8", 0x40);
  put(Permitted_operands, "b9", 0x40);
  put(Permitted_operands, "ba", 0x40);
  put(Permitted_operands, "bb", 0x40);
  put(Permitted_operands, "bc", 0x40);
  put(Permitted_operands, "bd", 0x40);
  put(Permitted_operands, "be", 0x40);
  put(Permitted_operands, "bf", 0x40);

  //// Class M: using ModR/M byte
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     0     0      |0       0     0     1

  // add
  put(Permitted_operands, "01", 0x01);
  put(Permitted_operands, "03", 0x01);
  // subtract
  put(Permitted_operands, "29", 0x01);
  put(Permitted_operands, "2b", 0x01);
  // and
  put(Permitted_operands, "21", 0x01);
  put(Permitted_operands, "23", 0x01);
  // or
  put(Permitted_operands, "09", 0x01);
  put(Permitted_operands, "0b", 0x01);
  // xor
  put(Permitted_operands, "31", 0x01);
  put(Permitted_operands, "33", 0x01);
  // compare
  put(Permitted_operands, "39", 0x01);
  put(Permitted_operands, "3b", 0x01);
  // copy
  put(Permitted_operands, "88", 0x01);
  put(Permitted_operands, "89", 0x01);
  put(Permitted_operands, "8a", 0x01);
  put(Permitted_operands, "8b", 0x01);
  // swap
  put(Permitted_operands, "87", 0x01);
  // copy address (lea)
  put(Permitted_operands, "8d", 0x01);

  //// Class N: op, ModR/M and subop (not r32)
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     0     0      |0       0     1     1
  put(Permitted_operands, "8f", 0x03);  // pop
  put(Permitted_operands, "d3", 0x03);  // shift
  put(Permitted_operands, "f7", 0x03);  // test/not/mul/div
  put(Permitted_operands, "ff", 0x03);  // jump/push/call

  //// Class O: op, ModR/M, subop (not r32) and imm8
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  0     1     0      |0       0     1     1
  put(Permitted_operands, "c1", 0x23);  // combine
  put(Permitted_operands, "c6", 0x23);  // copy

  //// Class P: op, ModR/M, subop (not r32) and imm32
  //  imm32 imm8  disp32 |disp16  disp8 subop modrm
  //  1     0     0      |0       0     1     1
  put(Permitted_operands, "81", 0x43);  // combine
  put(Permitted_operands, "c7", 0x43);  // copy

  // End Init Permitted Operands
}

#define HAS(bitvector, bit)  ((bitvector) & (1 << (bit)))
#define SET(bitvector, bit)  ((bitvector) | (1 << (bit)))
#define CLEAR(bitvector, bit)  ((bitvector) & (~(1 << (bit))))

void check_operands(const line& inst, const word& op) {
  if (!is_hex_byte(op)) return;
  uint8_t expected_bitvector = get(Permitted_operands, op.data);
  if (HAS(expected_bitvector, MODRM)) {
    check_operands_modrm(inst, op);
    compare_bitvector_modrm(inst, expected_bitvector, op);
  }
  else {
    compare_bitvector(inst, expected_bitvector, op);
  }
}

//: Many instructions can be checked just by comparing bitvectors.

void compare_bitvector(const line& inst, uint8_t expected, const word& op) {
  if (all_hex_bytes(inst) && has_operands(inst)) return;  // deliberately programming in raw hex; we'll raise a warning elsewhere
  uint8_t bitvector = compute_expected_operand_bitvector(inst);
  if (trace_contains_errors()) return;  // duplicate operand type
  if (bitvector == expected) return;  // all good with this instruction
  for (int i = 0;  i < NUM_OPERAND_TYPES;  ++i, bitvector >>= 1, expected >>= 1) {
//?     cerr << "comparing " << HEXBYTE << NUM(bitvector) << " with " << NUM(expected) << '\n';
    if ((bitvector & 0x1) == (expected & 0x1)) continue;  // all good with this operand
    const string& optype = Operand_type_name.at(i);
    if ((bitvector & 0x1) > (expected & 0x1))
      raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
    else
      raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << optype << " operand\n" << end();
    // continue giving all errors for a single instruction
  }
  // ignore settings in any unused bits
}

string maybe_name(const word& op) {
  if (!is_hex_byte(op)) return "";
  if (!contains_key(Name, op.data)) return "";
  // strip stuff in parens from the name
  const string& s = get(Name, op.data);
  return " ("+s.substr(0, s.find(" ("))+')';
}

uint32_t compute_expected_operand_bitvector(const line& inst) {
  set<string> operands_found;
  uint32_t bitvector = 0;
  for (int i = /*skip op*/1;  i < SIZE(inst.words);  ++i) {
    bitvector = bitvector | expected_bit_for_received_operand(inst.words.at(i), operands_found, inst);
    if (trace_contains_errors()) return INVALID_OPERANDS;  // duplicate operand type
  }
  return bitvector;
}

bool has_operands(const line& inst) {
  return SIZE(inst.words) > first_operand(inst);
}

int first_operand(const line& inst) {
  if (inst.words.at(0).data == "0f") return 2;
  if (inst.words.at(0).data == "f2" || inst.words.at(0).data == "f3") {
    if (inst.words.at(1).data == "0f")
      return 3;
    else
      return 2;
  }
  return 1;
}

// Scan the metadata of 'w' and return the expected bit corresponding to any operand type.
// Also raise an error if metadata contains multiple operand types.
uint32_t expected_bit_for_received_operand(const word& w, set<string>& instruction_operands, const line& inst) {
  uint32_t bv = 0;
  bool found = false;
  for (int i = 0;  i < SIZE(w.metadata);  ++i) {
    string/*copy*/ curr = w.metadata.at(i);
    string expected_metadata = curr;
    if (curr == "mod" || curr == "rm32" || curr == "r32" || curr == "scale" || curr == "index" || curr == "base")
      expected_metadata = "modrm";
    else if (!contains_key(Operand_type, curr)) continue;  // ignore unrecognized metadata
    if (found) {
      raise << "'" << w.original << "' has conflicting operand types; it should have only one\n" << end();
      return INVALID_OPERANDS;
    }
    if (instruction_operands.find(curr) != instruction_operands.end()) {
      raise << "'" << to_string(inst) << "': duplicate " << curr << " operand\n" << end();
      return INVALID_OPERANDS;
    }
    instruction_operands.insert(curr);
    bv = (1 << get(Operand_type, expected_metadata));
    found = true;
  }
  return bv;
}

void test_conflicting_operand_type() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "cd/software-interrupt 80/imm8/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '80/imm8/imm32' has conflicting operand types; it should have only one\n"
  );
}

//: Instructions computing effective addresses have more complex rules, so
//: we'll hard-code a common set of instruction-decoding rules.

void test_check_missing_mod_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81 0/add/subop       3/rm32/ebx 1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/add/subop 3/rm32/ebx 1/imm32' (combine rm32 with imm32 based on subop): missing mod operand\n"
  );
}

void check_operands_modrm(const line& inst, const word& op) {
  if (all_hex_bytes(inst)) return;  // deliberately programming in raw hex; we'll raise a warning elsewhere
  check_operand_metadata_present(inst, "mod", op);
  check_operand_metadata_present(inst, "rm32", op);
  // no check for r32; some instructions don't use it; just assume it's 0 if missing
  if (op.data == "81" || op.data == "8f" || op.data == "ff") {  // keep sync'd with 'help subop'
    check_operand_metadata_present(inst, "subop", op);
    check_operand_metadata_absent(inst, "r32", op, "should be replaced by subop");
  }
  if (trace_contains_errors()) return;
  if (metadata(inst, "rm32").data != "4") return;
  // SIB byte checks
  uint8_t mod = hex_byte(metadata(inst, "mod").data);
  if (mod != /*direct*/3) {
    check_operand_metadata_present(inst, "base", op);
    check_operand_metadata_present(inst, "index", op);  // otherwise why go to SIB?
  }
  else {
    check_operand_metadata_absent(inst, "base", op, "direct mode");
    check_operand_metadata_absent(inst, "index", op, "direct mode");
  }
  // no check for scale; 0 (2**0 = 1) by default
}

// same as compare_bitvector, with one additional exception for modrm-based
// instructions: they may use an extra displacement on occasion
void compare_bitvector_modrm(const line& inst, uint8_t expected, const word& op) {
  if (all_hex_bytes(inst) && has_operands(inst)) return;  // deliberately programming in raw hex; we'll raise a warning elsewhere
  uint8_t bitvector = compute_expected_operand_bitvector(inst);
  if (trace_contains_errors()) return;  // duplicate operand type
  // update 'expected' bitvector for the additional exception
  if (has_operand_metadata(inst, "mod")) {
    int32_t mod = parse_int(metadata(inst, "mod").data);
    switch (mod) {
    case 0:
      if (has_operand_metadata(inst, "rm32") && parse_int(metadata(inst, "rm32").data) == 5)
        expected |= (1<<DISP32);
      break;
    case 1:
      expected |= (1<<DISP8);
      break;
    case 2:
      expected |= (1<<DISP32);
      break;
    }
  }
  if (bitvector == expected) return;  // all good with this instruction
  for (int i = 0;  i < NUM_OPERAND_TYPES;  ++i, bitvector >>= 1, expected >>= 1) {
//?     cerr << "comparing for modrm " << HEXBYTE << NUM(bitvector) << " with " << NUM(expected) << '\n';
    if ((bitvector & 0x1) == (expected & 0x1)) continue;  // all good with this operand
    const string& optype = Operand_type_name.at(i);
    if ((bitvector & 0x1) > (expected & 0x1))
      raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << optype << " operand\n" << end();
    else
      raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << optype << " operand\n" << end();
    // continue giving all errors for a single instruction
  }
  // ignore settings in any unused bits
}

void check_operand_metadata_present(const line& inst, const string& type, const word& op) {
  if (!has_operand_metadata(inst, type))
    raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": missing " << type << " operand\n" << end();
}

void check_operand_metadata_absent(const line& inst, const string& type, const word& op, const string& msg) {
  if (has_operand_metadata(inst, type))
    raise << "'" << to_string(inst) << "'" << maybe_name(op) << ": unexpected " << type << " operand (" << msg << ")\n" << end();
}

void test_modrm_with_displacement() {
  Reg[EAX].u = 0x1;
  transform(
      "== code 0x1\n"
      // just avoid null pointer
      "8b/copy 1/mod/lookup+disp8 0/rm32/EAX 2/r32/EDX 4/disp8\n"  // copy *(EAX+4) to EDX
  );
  CHECK_TRACE_COUNT("error", 0);
}

void test_check_missing_disp8() {
  Hide_errors = true;
  transform(
      "== code 0x1\n"
      "89/copy 1/mod/lookup+disp8 0/rm32/EAX 1/r32/ECX\n"  // missing disp8
  );
  CHECK_TRACE_CONTENTS(
      "error: '89/copy 1/mod/lookup+disp8 0/rm32/EAX 1/r32/ECX' (copy r32 to rm32): missing disp8 operand\n"
  );
}

void test_check_missing_disp32() {
  Hide_errors = true;
  transform(
      "== code 0x1\n"
      "8b/copy 0/mod/indirect 5/rm32/.disp32 2/r32/EDX\n"  // missing disp32
  );
  CHECK_TRACE_CONTENTS(
      "error: '8b/copy 0/mod/indirect 5/rm32/.disp32 2/r32/EDX' (copy rm32 to r32): missing disp32 operand\n"
  );
}

void test_conflicting_operands_in_modrm_instruction() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "01/add 0/mod 3/mod\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '01/add 0/mod 3/mod' has conflicting mod operands\n"
  );
}

void test_conflicting_operand_type_modrm() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "01/add 0/mod 3/rm32/r32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '3/rm32/r32' has conflicting operand types; it should have only one\n"
  );
}

void test_check_missing_rm32_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81 0/add/subop 0/mod            1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/add/subop 0/mod 1/imm32' (combine rm32 with imm32 based on subop): missing rm32 operand\n"
  );
}

void test_check_missing_subop_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81             0/mod 3/rm32/ebx 1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/mod 3/rm32/ebx 1/imm32' (combine rm32 with imm32 based on subop): missing subop operand\n"
  );
}

void test_check_missing_base_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81 0/add/subop 0/mod/indirect 4/rm32/use-sib 1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 1/imm32' (combine rm32 with imm32 based on subop): missing base operand\n"
  );
}

void test_check_missing_index_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81 0/add/subop 0/mod/indirect 4/rm32/use-sib 0/base 1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 0/base 1/imm32' (combine rm32 with imm32 based on subop): missing index operand\n"
  );
}

void test_check_missing_base_operand_2() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "81 0/add/subop 0/mod/indirect 4/rm32/use-sib 2/index 3/scale 1/imm32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '81 0/add/subop 0/mod/indirect 4/rm32/use-sib 2/index 3/scale 1/imm32' (combine rm32 with imm32 based on subop): missing base operand\n"
  );
}

void test_check_extra_displacement() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 4/disp8\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 4/disp8' (copy r32 to rm32): unexpected disp8 operand\n"
  );
}

void test_check_duplicate_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 1/r32\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '89/copy 0/mod/indirect 0/rm32/EAX 1/r32/ECX 1/r32': duplicate r32 operand\n"
  );
}

void test_check_base_operand_not_needed_in_direct_mode() {
  run(
      "== code 0x1\n"
      "81 0/add/subop 3/mod/indirect 4/rm32/use-sib 1/imm32\n"
  );
  CHECK_TRACE_COUNT("error", 0);
}

void test_extra_modrm() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "59/pop-to-ECX  3/mod/direct 1/rm32/ECX 4/r32/ESP\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '59/pop-to-ECX 3/mod/direct 1/rm32/ECX 4/r32/ESP' (pop top of stack to ECX): unexpected modrm operand\n"
  );
}

//:: similarly handle multi-byte opcodes

void check_operands_0f(const line& inst) {
  assert(inst.words.at(0).data == "0f");
  if (SIZE(inst.words) == 1) {
    raise << "opcode '0f' requires a second opcode\n" << end();
    return;
  }
  word op = preprocess_op(inst.words.at(1));
  if (!contains_key(Name_0f, op.data)) {
    raise << "unknown 2-byte opcode '0f " << op.data << "'\n" << end();
    return;
  }
  check_operands_0f(inst, op);
}

void check_operands_f3(const line& /*unused*/) {
  raise << "no supported opcodes starting with f3\n" << end();
}

void test_check_missing_disp32_operand() {
  Hide_errors = true;
  run(
      "== code 0x1\n"
      "  0f 84  # jmp if ZF to ??\n"
  );
  CHECK_TRACE_CONTENTS(
      "error: '0f 84' (jump disp32 bytes away if equal, if ZF is set): missing disp32 operand\n"
  );
}

:(before "End Globals")
map</*op*/string, /*bitvector*/uint8_t> Permitted_operands_0f;
:(before "End Init Permitted Operands")
//// Class D: just op and disp32
//  imm32 imm8  disp32 |disp16  disp8 subop modrm
//  0     0     1      |0       0     0     0
put_new(Permitted_operands_0f, "82", 0x10);
put_new(Permitted_operands_0f, "83", 0x10);
put_new(Permitted_operands_0f, "84", 0x10);
put_new(Permitted_operands_0f, "85", 0x10);
put_new(Permitted_operands_0f, "86", 0x10);
put_new(Permitted_operands_0f, "87", 0x10);
put_new(Permitted_operands_0f, "8c", 0x10);
put_new(Permitted_operands_0f, "8d", 0x10);
put_new(Permitted_operands_0f, "8e", 0x10);
put_new(Permitted_operands_0f, "8f", 0x10);

//// Class M: using ModR/M byte
//  imm32 imm8  disp32 |disp16  disp8 subop modrm
//  0     0     0      |0       0     0     1
put_new(Permitted_operands_0f, "af", 0x01);

:(code)
void check_operands_0f(const line& inst, const word& op) {
  uint8_t expected_bitvector = get(Permitted_operands_0f, op.data);
  if (HAS(expected_bitvector, MODRM))
    check_operands_modrm(inst, op);
  compare_bitvector_0f(inst, CLEAR(expected_bitvector, MODRM), op);
}

void compare_bitvector_0f(const line& inst, uint8_t expected, const word& op) {
  if (all_hex_bytes(inst) && has_operands(inst)) return;  // deliberately programming in raw hex; we'll raise a warning elsewhere
  uint8_t bitvector = compute_expected_operand_bitvector(inst);
  if (trace_contains_errors()) return;  // duplicate operand type
  if (bitvector == expected) return;  // all good with this instruction
  for (int i = 0;  i < NUM_OPERAND_TYPES;  ++i, bitvector >>= 1, expected >>= 1) {
//?     cerr << "comparing " << HEXBYTE << NUM(bitvector) << " with " << NUM(expected) << '\n';
    if ((bitvector & 0x1) == (expected & 0x1)) continue;  // all good with this operand
    const string& optype = Operand_type_name.at(i);
    if ((bitvector & 0x1) > (expected & 0x1))
      raise << "'" << to_string(inst) << "'" << maybe_name_0f(op) << ": unexpected " << optype << " operand\n" << end();
    else
      raise << "'" << to_string(inst) << "'" << maybe_name_0f(op) << ": missing " << optype << " operand\n" << end();
    // continue giving all errors for a single instruction
  }
  // ignore settings in any unused bits
}

string maybe_name_0f(const word& op) {
  if (!is_hex_byte(op)) return "";
  if (!contains_key(Name_0f, op.data)) return "";
  // strip stuff in parens from the name
  const string& s = get(Name_0f, op.data);
  return " ("+s.substr(0, s.find(" ("))+')';
}

string tolower(const char* s) {
  ostringstream out;
  for (/*nada*/;  *s;  ++s)
    out << static_cast<char>(tolower(*s));
  return out.str();
}

#undef HAS
#undef SET
#undef CLEAR

:(before "End Includes")
#include<cctype>