I don't want to give up

[mvanthoor]

Why do you want to come up with something new? You already did: you have a well-respected, 2400 ELO+ engine that is an original work. Better yet, you have an entire type of bitboard named after you in the chess programming wiki.

If I was in your position, I'd just try to improve RomiChess and see how far it can be taken with only self-written code.

[Mike Sherwin]

Why do you want to come up with something new? You already did: you have a well-respected, 2400 ELO+ engine that is an original work. Better yet, you have an entire type of bitboard named after you in the chess programming wiki.

If I was in your position, I'd just try to improve RomiChess and see how far it can be taken with only self-written code.

Good questions and thank you for the accolades! RomiChess uses nameless structures which do not seem to be supported in modern compilers. Also, what I am trying to do now is what I wanted to do 30 years ago but settled for something original yet closer to normal. I don't know if those are good enough reasons?

[mvanthoor]

Good questions and thank you for the accolades! RomiChess uses nameless structures which do not seem to be supported in modern compilers. Also, what I am trying to do now is what I wanted to do 30 years ago but settled for something original yet closer to normal. I don't know if those are good enough reasons?

Everything is a good enough reason, if you think it should be.

I've wanted to have my own chess engine for over 20 years. There was no good -reason- to write one though, apart from wanting to write one, because there are so many already. I felt it wasn't worth it because it would just be another C/C++ chess engine among hundreds.

then Rust came out, and since Rust Edition 2018, I feel the language matured enough for a serious project and I wanted to learn it. To do so I need something to program... and as Rust aims to be a replacement for C/C++, that chess engine seemed to be a pretty good idea. Two flies with one stone. Thus, I slowly started to try and write something.

The two goals with regard to playing strength that I have are, for now:
- Beat Fritz 11 (CCRL 2852) as a single-threaded version, in a 100 game match.
- Then implement multi-threading, and beat Deep Fritz 13 (CCRL 3034).

Why? Because I grew up with Fritz, and I happen to own a single-threaded version of version 11, and a multi-threaded version of Deep Fritz 13. (I'm not particularly interested in beating newer versions of "Fritz", because those are just that in name; the engine is not Fritz anymore. Version 13 was the last version by Frans Morsch before he retired.)

So my reason to write the chess engine is to learn Rust, and the goal is to beat both Fritz 11 and Deep Fritz 13 in a 100 game match. (And I'll write the accompanying documentation website.) After that? We'll see. I don't know yet.

So, if your reason to write this is because it's what you INTENDED to do 30 years ago, and you think you can still do it, go for it. In the end, you will succeed. You only need a goal to achieve. That could be as simple as "I want to have a working chess engine using this concept", or it could be "I want it to be at least as strong as RomiChess without actually using any code from RomiChess."

[Mike Sherwin]

Good questions and thank you for the accolades! RomiChess uses nameless structures which do not seem to be supported in modern compilers. Also, what I am trying to do now is what I wanted to do 30 years ago but settled for something original yet closer to normal. I don't know if those are good enough reasons?

Everything is a good enough reason, if you think it should be.

I've wanted to have my own chess engine for over 20 years. There was no good -reason- to write one though, apart from wanting to write one, because there are so many already. I felt it wasn't worth it because it would just be another C/C++ chess engine among hundreds.

then Rust came out, and since Rust Edition 2018, I feel the language matured enough for a serious project and I wanted to learn it. To do so I need something to program... and as Rust aims to be a replacement for C/C++, that chess engine seemed to be a pretty good idea. Two flies with one stone. Thus, I slowly started to try and write something.

The two goals with regard to playing strength that I have are, for now:
- Beat Fritz 11 (CCRL 2852) as a single-threaded version, in a 100 game match.
- Then implement multi-threading, and beat Deep Fritz 13 (CCRL 3034).

Why? Because I grew up with Fritz, and I happen to own a single-threaded version of version 11, and a multi-threaded version of Deep Fritz 13. (I'm not particularly interested in beating newer versions of "Fritz", because those are just that in name; the engine is not Fritz anymore. Version 13 was the last version by Frans Morsch before he retired.)

So my reason to write the chess engine is to learn Rust, and the goal is to beat both Fritz 11 and Deep Fritz 13 in a 100 game match. (And I'll write the accompanying documentation website.) After that? We'll see. I don't know yet.

So, if your reason to write this is because it's what you INTENDED to do 30 years ago, and you think you can still do it, go for it. In the end, you will succeed. You only need a goal to achieve. That could be as simple as "I want to have a working chess engine using this concept", or it could be "I want it to be at least as strong as RomiChess without actually using any code from RomiChess."

I'm looking forward to your engine being released! Everyone has a world view. The way things work. The way things should work. And it seems that everyone has their own standard of measure by which they measure their world view for themselves and unfortunately far too often they use their standard to measure their world view for others. My world view cannot be measured by anyone else's standard. Try waking up with a near memory wipe every morning and then tell me all I need is a goal to achieve. Right now I'm just trying to reconstruct the changes I started to make to my code yesterday. Goals? Sometimes I can't even remember what my short term goals are. My new engine if successful won't be anything like a traditional engine. It won't even have a positional evaluation function, no pst or pawn structure or king safety or anything traditional. So how would you suggest I reuse code from RomiChess? I'm not upset. I just want you to realize that your measuring sticks are not universal. Best wishes for your endeavor!

[mvanthoor]

I'm looking forward to your engine being released! Everyone has a world view. The way things work. The way things should work. And it seems that everyone has their own standard of measure by which they measure their world view for themselves and unfortunately far too often they use their standard to measure their world view for others. My world view cannot be measured by anyone else's standard. Try waking up with a near memory wipe every morning and then tell me all I need is a goal to achieve. Right now I'm just trying to reconstruct the changes I started to make to my code yesterday. Goals? Sometimes I can't even remember what my short term goals are. My new engine if successful won't be anything like a traditional engine. It won't even have a positional evaluation function, no pst or pawn structure or king safety or anything traditional. So how would you suggest I reuse code from RomiChess? I'm not upset. I just want you to realize that your measuring sticks are not universal. Best wishes for your endeavor!

Thanks for your message I can't imagine forgetting everything that happened yesterday and not remembering anything today. I hope it doesn't happen to me... that's the only thing I can say about it.

However, I can imagine going blind from one day to the next. My vision is 34% at the best of times, and everything but 7% of that is in my right eye. I just had a cataract extraction in my right eye. I know this surgery is the one most often performed on humans, and the one with the highest success rate, of about 98% without complications.

All went well. Nevertheless, if I had been one of the 2% of people with complications, I could have gone blind. (All I'd have left would be able to see light and dark, and general colored shapes.) I've been scared *** for months; surgery was postponed because of covid-19. Normally I'm not easily scared.

So I can very well understand that one person's way of measuring life and success are not fit for another.

However, you do need a goal to do something; I assume you don't just do random stuff for nothing all the time. In your case, it seems to be a desire to do something, anything, chess engine related, in an non-traditional way. That can be creating your own variant of bitboards, or an engine without a traditional evaluation. If your desire is to do something that hasn't been done before, then it is your goal to have a working engine using these techniques you come up with. If you create an engine that plays legal chess, you will have achieved it.

I've slowly picked up development of my engine again, and it's going well so far. I hope to release something this year. You did write RomiChess and you finished it. I hope you can achieve the dream of creating the chess engine you wanted 30 years ago.

I'll certainly include RomiChess in my testing tournaments at some point, after my engine actually stands a chance of scoring some points against it. Knowing where that engine came from, it'd be an honor to set it as one of my benchmarks around the 2400 level. I prefer engines of which I have been able to follow the development such as Stash and Weiss, that have some sort of status within the chess programming community such as TSCP and VICE, or that have some sort of interesting story behind them such as yours; and in my case, Fritz, just because I grew up with Frans Morsch programs.

-

[Mike Sherwin]

I'm looking forward to your engine being released! Everyone has a world view. The way things work. The way things should work. And it seems that everyone has their own standard of measure by which they measure their world view for themselves and unfortunately far too often they use their standard to measure their world view for others. My world view cannot be measured by anyone else's standard. Try waking up with a near memory wipe every morning and then tell me all I need is a goal to achieve. Right now I'm just trying to reconstruct the changes I started to make to my code yesterday. Goals? Sometimes I can't even remember what my short term goals are. My new engine if successful won't be anything like a traditional engine. It won't even have a positional evaluation function, no pst or pawn structure or king safety or anything traditional. So how would you suggest I reuse code from RomiChess? I'm not upset. I just want you to realize that your measuring sticks are not universal. Best wishes for your endeavor!

Thanks for your message I can't imagine forgetting everything that happened yesterday and not remembering anything today. I hope it doesn't happen to me... that's the only thing I can say about it.

However, I can imagine going blind from one day to the next. My vision is 34% at the best of times, and everything but 7% of that is in my right eye. I just had a cataract extraction in my right eye. I know this surgery is the one most often performed on humans, and the one with the highest success rate, of about 98% without complications.

All went well. Nevertheless, if I had been one of the 2% of people with complications, I could have gone blind. (All I'd have left would be able to see light and dark, and general colored shapes.) I've been scared *** for months; surgery was postponed because of covid-19. Normally I'm not easily scared.

So I can very well understand that one person's way of measuring life and success are not fit for another.

However, you do need a goal to do something; I assume you don't just do random stuff for nothing all the time. In your case, it seems to be a desire to do something, anything, chess engine related, in an non-traditional way. That can be creating your own variant of bitboards, or an engine without a traditional evaluation. If your desire is to do something that hasn't been done before, then it is your goal to have a working engine using these techniques you come up with. If you create an engine that plays legal chess, you will have achieved it.

I've slowly picked up development of my engine again, and it's going well so far. I hope to release something this year. You did write RomiChess and you finished it. I hope you can achieve the dream of creating the chess engine you wanted 30 years ago.

I'll certainly include RomiChess in my testing tournaments at some point, after my engine actually stands a chance of scoring some points against it. Knowing where that engine came from, it'd be an honor to set it as one of my benchmarks around the 2400 level. I prefer engines of which I have been able to follow the development such as Stash and Weiss, that have some sort of status within the chess programming community such as TSCP and VICE, or that have some sort of interesting story behind them such as yours; and in my case, Fritz, just because I grew up with Frans Morsch programs.

-

Cool! Anyway I was born this way. I was a blue baby born six weeks premature. I was not expected to live. But I did. I also have a hole in my heart between the chambers somewhere along with a very pronounced heart murmur. I was not supposed to live to my 40th birthday. But, here I am. I was told certain intellectual pursuits were beyond my ability. Yet I wrote one of the most successful learning chess engines ever, at the time. I'm hoping that I have one more impossible feat left in me before I'm gone.

[Mike Sherwin]

The changes have been made. It is mechanically sound as many 8 ply searches were made and when all the moves are undone the original position is reached without corruption. The 8 ply searches took anywhere from under a second to several seconds. However, somehow I have skewed the search so that it does not want to win material, lol. At least so far it only makes legal moves and does not crash. I said so far.

Code: Select all

// Bricabrac
// A chess engine by Michael J Sherwin

#include <intrin.h>
#include <iostream>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>

#define equates 1
#ifdef equates
typedef signed char s08;
typedef unsigned char u08;
typedef int s32;
typedef unsigned long u32;
typedef long long s64;
typedef unsigned long long u64;


constexpr auto one = 1ull;
constexpr auto INF = 0x7fff;
constexpr auto STOP = INF;
constexpr auto ColA = 0;
constexpr auto Row8 = 7;
constexpr auto ILLEGAL = 0xffff;
constexpr auto VP = 100;
constexpr auto VN = 300;
constexpr auto VB = 300;
constexpr auto VR = 500;
constexpr auto VQ = 900;
constexpr auto VK = 4000;
constexpr auto Vq = 800;
constexpr auto Vn = 200;
constexpr auto Vr = 400;
constexpr auto Vb = 200;
constexpr auto WOCCS = 0x0000000000000060;
constexpr auto WOCCL = 0x000000000000000e;
constexpr auto BOCCS = 0x6000000000000000;
constexpr auto BOCCL = 0x0e00000000000000;
constexpr auto WATKS = 0x0000000000000070;
constexpr auto WATKL = 0x000000000000001c;
constexpr auto BATKS = 0x7000000000000000;
constexpr auto BATKL = 0x1c00000000000000;

enum { BLACK, WHITE};

enum { B, R, N, Q};

enum { OO, WP, WN, WB, WR, WRC, WQ, WK, WC, BP, BN, BB, BR, BRC, BQ, BK, BC,
       Wd, We, Wb, Wr, Wn, Wq, Bd, Be, Bb, Br, Bn, Bq, WS, WL, BS, BL };

enum { RANK1, RANK2, RANK3, RANK4, RANK5, RANK6, RANK7, RANK8 };

enum { A1, B1, C1, D1, E1, F1, G1, H1,
       A2, B2, C2 ,D2, E2, F2, G2, H2,
       A3, B3, C3, D3, E3, F3, G3, H3,
       A4, B4, C4, D4, E4, F4, G4, H4,
       A5, B5, C5, D5, E5, F5, G5, H5,
       A6, B6, C6, D6, E6, F6, G6, H6,
       A7, B7, C7, D7, E7, F7, G7, H7,
       A8, B8, C8, D8, E8, F8, G8, H8 };

enum { EXIT, GETCMD, BRICABRAC, MOVE};
#endif 

#define definitions 1
#ifdef definitions
struct Move {
  s32 fs;
  s32 ts;
  s32 type;
  s32 score;
  s32 wstats;
  s32 bstats;
  s32 status;
};

struct Thread {
  s32 wtm;
  s32 ply;
  s32 start;
  s32 mat[2];
  s32 board[64];
  u64 piece[2];
  u64 king[2];
  u64 epbb[100];
  s32 fifty[100];
  Move move[10000];
};

#define wtm   t->wtm
#define ply   t->ply
#define fifty t->fifty
#define start t->start
#define mat   t->mat
#define board t->board
#define piece t->piece
#define king  t->king
#define epbb  t->epbb
#define tsbb  t->tsbb
#define move  t->move
#endif

#define variables 1
#ifdef variables
Thread thread;
Thread* t;
s32 bricabrac;
s32 gamePly;
s32 sd;

u64 wPawnMoves[64];
u64 wPawnCapts[64];
u64 bPawnMoves[64];
u64 bPawnCapts[64];
u64 knightMoves[64];
u64 kingMoves[64];

u64 qss[64][256][8];
u64 bob[64];
u64 rob[64];

u64 above[65];
u64 below[65];

Move gameMoves[1000];

s32 value[] = { OO, VP, VN, VB, VR, VR, VQ, VK, VK, VP, VN, VB, VR, VR, VQ, VK, VK,
                Vb, Vr, Vn, Vq, Vb, Vr, Vn, Vq };

u08 startFen[] = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";

#endif

void PrintBoard(Thread* t) {
  s32 x, y, sq, pce;

  u08 fig[] = { ".PNBRRQKKpnbrrqkk" };

  for (y = 7; y >= 0; y--) {
    for (x = 0; x < 8; x++) {
      sq = ((y << 3) + x);
      pce = board[sq];
      std::cout << "  " << fig[pce];
    }
    std::cout << std::endl;
  }
  std::cout << std::endl;
}

s32 LoadFen(Thread* t, u08* f) {
  s32 row, col, sq, fs, pce; 

  for (sq = A1; sq <= H8; sq++) board[sq] = OO;

  col = ColA;
  row = Row8;
  fs = 56;

  mat[WHITE] = OO;
  mat[BLACK] = OO; 
  piece[WHITE] = OO;
  piece[BLACK] = OO;

  for (;; f++) {
    if (*f == ' ') break;
    switch (*f) {
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
      col += *f - '0';
      fs = (row * 8 + col) & 63;
      continue;
    case '/':
      col = ColA;
      row--;
      fs = (row * 8 + col) & 63;
      continue;
    case 'P':
      pce = WP;
      mat[WHITE] += VP;
      piece[WHITE] ^= one << fs;
      break;
    case 'N':
      pce = WN;
      mat[WHITE] += VN;
      piece[WHITE] ^= one << fs;
      break;
    case 'B':
      pce = WB;
      mat[WHITE] += VB;
      piece[WHITE] ^= one << fs;
      break;
    case 'R':
      pce = WR;
      mat[WHITE] += VR;
      piece[WHITE] ^= one << fs;
      break;
    case 'Q':
      pce = WQ;
      mat[WHITE] += VQ;
      piece[WHITE] ^= one << fs;
      break;
    case 'K':
      pce = WK;
      piece[WHITE] ^= one << fs;
      king[WHITE] = one << fs;
      break;
    case 'p':
      pce = BP;
      mat[BLACK] += VP;
      piece[BLACK] ^= one << fs;
      break;
    case 'n':
      pce = BN;
      mat[BLACK] += VN;
      piece[BLACK] ^= one << fs;
      break;
    case 'b':
      pce = BB;
      mat[BLACK] += VB;
      piece[BLACK] ^= one << fs;
      break;
    case 'r':
      pce = BR;
      mat[BLACK] += VR;
      piece[BLACK] ^= one << fs;
      break;
    case 'q':
      pce = BQ;
      mat[BLACK] += VQ;
      piece[BLACK] ^= one << fs;
      break;
    case 'k':
      pce = BK;
      piece[BLACK] ^= one << fs;
      king[BLACK] = one << fs;
      break;
    default:
      return false;
    }
    board[fs] = pce;
    col++;
    fs = (row * 8 + col) & 63;
  }
  f++;
  switch (*f++) {
  case 'w':
    wtm = WHITE;
    break;
  case 'b':
    wtm = BLACK;
    break;
  default:
    return false;
  }
  if (*f++ != ' ') return false;
  if (*f == '-') {
    f++;
    if (*f++ != ' ') return false;
  }
  else {
    for (;;) {
      if (*f == ' ') {
        f++;
        break;
      }
      switch (*f++) {
      case 'K':
        board[E1] = WC;
        board[H1] = WRC;
        break;
      case 'Q':
        board[E1] = WC;
        board[A1] = WRC;
        break;
      case 'k':
        board[E8] = BC;
        board[H8] = BRC;
        break;
      case 'q':
        board[E8] = BC;
        board[A8] = BRC;
        break;
      default:
        return false;
      }
    }
  }
  epbb[OO] = OO;
  if (*f == '-') f++;
  else {
    if (*f < 'a' || *f > 'h') return false;
    if (*(f + 1) < '0' || *(f + 1) > '7') return false;
    row = *(f + 1) - '1';
    col = *f - 'a';
    epbb[OO] = one << (row * 8 + col);
    f += 2;
  }
  if (*f++ != ' ') return false;
  fifty[OO] = OO;
  for (;;) {
    if (!isdigit(*f)) break;
    fifty[OO] *= 10;
    fifty[OO] += *f++ - '0';
  }
  if (*f++ != ' ') return false;
  start = 0;
  for (;;) {
    if (!isdigit(*f)) break;
    start *= 10;
    start += *f++ - '0';
  }
  if (start < 1) return false;
  while (*f == ' ') f++;
  if (*f != '\0') return false;
  return true;
}

void MakeMove(Thread* t, Move* m) {
  s32 ctype = 0, sq;

  board[m->fs] = OO;
  piece[wtm] ^= one << m->fs;
  piece[wtm] ^= one << m->ts;

  switch (m->type) {
  case OO: break;
  case WP:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WP;
    break;
  case WN:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WN;
    break;
  case WB:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WB;
    break;
  case WR:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WR;
    break;
  case WRC:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WR;
    break;
  case WQ:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WQ;
    break;
  case WK:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WK;
    king[WHITE] ^= one << m->fs;
    king[WHITE] ^= one << m->ts;
    break;
  case WC:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WK;
    king[WHITE] ^= one << m->fs;
    king[WHITE] ^= one << m->ts;
    break;
  case BP:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BP;
    break;
  case BN:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BN;
    break;
  case BB:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BB;
    break;
  case BR:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BR;
    break;
  case BRC:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BR;
    break;
  case BQ:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BQ;
    break;
  case BK:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BK;
    king[BLACK] ^= one << m->fs;
    king[BLACK] ^= one << m->ts;
    break;
  case BC:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BK;
    king[BLACK] ^= one << m->fs;
    king[BLACK] ^= one << m->ts;
    break;
  case Wd:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WP;
    epbb[ply + 1] = (u64)(m->fs + 16 == m->ts ) << (m->fs + 8);
    break;
  case We:
    sq = m->ts - ((epbb[ply] == (one << m->ts)) << 3);
    ctype = board[sq];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << sq;
    board[sq] = OO;
    board[m->ts] = WP; 
    break;
  case Wb:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WB;
    mat[WHITE] += 200;
    break;
  case Wr:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WR;
    mat[WHITE] += 400;
    break;
  case Wn:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WN;
    mat[WHITE] += 200;
    break;
  case Wq:
    ctype = board[m->ts];
    mat[BLACK] -= value[ctype];
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = WQ;
    mat[WHITE] += 800;
    break;
  case Bd:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BP;
    epbb[ply + 1] = (u64)(m->fs - 16 == m->ts) << (m->fs - 8);
    break;
  case Be:
    sq = m->ts + ((epbb[ply] == (one << m->ts)) << 3);
    ctype = board[sq];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << sq;
    board[sq] = OO;
    board[m->ts] = BP;
    break;
  case Bb:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BB;
    mat[BLACK] += 200;
    break;
  case Br:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BR;
    mat[BLACK] += 400;
    break;
  case Bn:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BN;
    mat[BLACK] += 200;
    break;
  case Bq:
    ctype = board[m->ts];
    mat[WHITE] -= value[ctype];
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    board[m->ts] = BQ;
    mat[BLACK] += 800;
    break;
  case WS:
    ctype = OO;
    board[G1] = WK;
    board[H1] = OO;
    board[F1] = WR;
    piece[WHITE] ^= one << H1;
    piece[WHITE] ^= one << F1;
    break;
  case WL:
    ctype = OO;
    board[C1] = WK;
    board[A1] = OO;
    board[D1] = WR;
    piece[WHITE] ^= one << A1;
    piece[WHITE] ^= one << D1;
    break;
  case BS:
    ctype = OO;
    board[G8] = BK;
    board[H8] = OO;
    board[F8] = BR;
    piece[BLACK] ^= one << H8;
    piece[BLACK] ^= one << F8;
    break;
  case BL:
    ctype = OO;
    board[C8] = BK;
    board[A8] = OO;
    board[D8] = BR;
    piece[BLACK] ^= one << A8;
    piece[BLACK] ^= one << D8;
    break;
  }
  m->type |= ctype << 6;
  wtm = 1 - wtm;
  ply++;
}

void TakeBack(Thread* t, Move* m) {
  s32 ctype, sq;

  ply--;
  wtm = 1 - wtm;

  piece[wtm] ^= one << m->ts;
  piece[wtm] ^= one << m->fs;
  ctype = m->type >> 6;
  mat[1 - wtm] += value[ctype];
  m->type &= 0x3f;

  switch (m->type) {
  case OO: break;
  case WP:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WN:
    board[m->ts] = ctype;
    board[m->fs] = WN;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WB:
    board[m->ts] = ctype;
    board[m->fs] = WB;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WR:
    board[m->ts] = ctype;
    board[m->fs] = WR;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WRC:
    board[m->ts] = ctype;
    board[m->fs] = WRC;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WQ:
    board[m->ts] = ctype;
    board[m->fs] = WQ;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WK:
    board[m->ts] = ctype;
    board[m->fs] = WK;
    king[WHITE] ^= one << m->fs;
    king[WHITE] ^= one << m->ts;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WC:
    board[m->ts] = ctype;
    board[m->fs] = WC;
    king[WHITE] ^= one << m->fs;
    king[WHITE] ^= one << m->ts;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BP:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BN:
    board[m->ts] = ctype;
    board[m->fs] = BN;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BB:
    board[m->ts] = ctype;
    board[m->fs] = BB;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BR:
    board[m->ts] = ctype;
    board[m->fs] = BR;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BRC:
    board[m->ts] = ctype;
    board[m->fs] = BRC;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BQ:
    board[m->ts] = ctype;
    board[m->fs] = BQ;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BK:
    board[m->ts] = ctype;
    board[m->fs] = BK;
    king[BLACK] ^= one << m->fs;
    king[BLACK] ^= one << m->ts;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case BC:
    board[m->ts] = ctype;
    board[m->fs] = BC;
    king[BLACK] ^= one << m->fs;
    king[BLACK] ^= one << m->ts;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Wd:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    epbb[ply + 1] = OO;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case We:
    sq = m->ts - ((epbb[ply] == (one << m->ts)) << 3);
    board[m->ts] = OO;
    board[sq] = ctype;
    piece[BLACK] ^= (u64)(ctype != OO) << sq;
    board[m->fs] = WP;
    break;
  case Wb:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    mat[WHITE] -= 200;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Wr:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    mat[WHITE] -= 400;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Wn:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    mat[WHITE] -= 200;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Wq:
    board[m->ts] = ctype;
    board[m->fs] = WP;
    mat[WHITE] -= 800;
    piece[BLACK] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Bd:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    epbb[ply + 1] = OO;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Be:
    sq = m->ts + ((epbb[ply] == (one << m->ts)) << 3);
    board[m->ts] = OO;
    board[sq] = ctype;
    piece[WHITE] ^= (u64)(ctype != OO) << sq;
    board[m->fs] = BP;
    break;
  case Bb:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    mat[BLACK] -= 200;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Br:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    mat[BLACK] -= 400;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Bn:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    mat[BLACK] -= 200;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case Bq:
    board[m->ts] = ctype;
    board[m->fs] = BP;
    mat[BLACK] -= 800;
    piece[WHITE] ^= (u64)(ctype != OO) << m->ts;
    break;
  case WS:
    board[G1] = OO;
    board[E1] = WC;
    board[H1] = WRC;
    board[F1] = OO;
    piece[WHITE] ^= one << H1;
    piece[WHITE] ^= one << F1;
    break;
  case WL:
    board[C1] = OO;
    board[E1] = WC;
    board[A1] = WRC;
    board[D1] = OO;
    piece[WHITE] ^= one << A1;
    piece[WHITE] ^= one << D1;
    break;
  case BS:
    board[G8] = OO;
    board[E8] = BC;
    board[H8] = BRC;
    board[F8] = OO;
    piece[BLACK] ^= one << H8;
    piece[BLACK] ^= one << F8;
    break;
  case BL:
    board[C8] = OO;
    board[E8] = BC;
    board[A8] = BRC;
    board[D8] = OO;
    piece[BLACK] ^= one << A8;
    piece[BLACK] ^= one << D8;
    break;
  }
}

s32 AtkByWhite(Thread* t, u64 bb) {
  u32 ts, fs;
  u64 b, aPieces = piece[WHITE] | piece[BLACK];
  do {
    _BitScanForward64(&ts, bb);
    bb ^= one << ts;
    b = bPawnCapts[ts];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == WP) return true;
    }
    b = knightMoves[ts] & piece[WHITE];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == WN) return true;
    }
    b = kingMoves[ts];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == WK) return true;
    }
    b = qss[ts][(aPieces >> (ts & 56)) & 127][0]
      & qss[ts][(aPieces >>  8) & 255][1]
      & qss[ts][(aPieces >> 16) & 255][2]
      & qss[ts][(aPieces >> 24) & 255][3]
      & qss[ts][(aPieces >> 32) & 255][4]
      & qss[ts][(aPieces >> 40) & 255][5]
      & qss[ts][(aPieces >> 48) & 255][6]
      & bob[ts]
      & piece[WHITE];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == WB || board[fs] == WQ) return true;
    }
    b = qss[ts][(aPieces >> (ts & 56)) & 127][0]
      & qss[ts][(aPieces >> 8)  & 255][1]
      & qss[ts][(aPieces >> 16) & 255][2]
      & qss[ts][(aPieces >> 24) & 255][3]
      & qss[ts][(aPieces >> 32) & 255][4]
      & qss[ts][(aPieces >> 40) & 255][5]
      & qss[ts][(aPieces >> 48) & 255][6]
      & rob[ts]
      & piece[WHITE];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == WR || board[fs] == WQ) return true;
    }
  } while (bb);
  return false;
}

s32 AtkByBlack(Thread* t, u64 bb) {
  u32 ts, fs;
  u64 b, aPieces = piece[WHITE] | piece[BLACK];
  do {
    _BitScanForward64(&ts, bb);
    bb ^= one << ts;
    b = wPawnCapts[ts];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == BP) return true;
    }
    b = knightMoves[ts] & piece[BLACK];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == BN) return true;
    }
    b = kingMoves[ts];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == BK) return true;
    }
    b = qss[ts][(aPieces >> (ts & 56)) & 127][0]
      & qss[ts][(aPieces >> 8)  & 255][1]
      & qss[ts][(aPieces >> 16) & 255][2]
      & qss[ts][(aPieces >> 24) & 255][3]
      & qss[ts][(aPieces >> 32) & 255][4]
      & qss[ts][(aPieces >> 40) & 255][5]
      & qss[ts][(aPieces >> 48) & 255][6]
      & bob[ts]
      & piece[BLACK];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == BB || board[fs] == BQ) return true;
    }
    b = qss[ts][(aPieces >> (ts & 56)) & 127][0]
      & qss[ts][(aPieces >> 8)  & 255][1]
      & qss[ts][(aPieces >> 16) & 255][2]
      & qss[ts][(aPieces >> 24) & 255][3]
      & qss[ts][(aPieces >> 32) & 255][4]
      & qss[ts][(aPieces >> 40) & 255][5]
      & qss[ts][(aPieces >> 48) & 255][6]
      & rob[ts]
      & piece[BLACK];
    while (b) {
      _BitScanForward64(&fs, b);
      b ^= one << fs;
      if (board[fs] == BR || board[fs] == BQ) return true;
    }
  } while (bb);
  return false;
}

__forceinline s32 Sort(Thread* t, Move* m, s32 n) {
  s32 i = 0, high = -INF;
  Move* mov;
  for (; n > OO; n--) {
    mov = m - n;
    if (mov->status == false && mov->score > high) {
      high = mov->score;
      i = n;
    }
  }
  (m - i)->status = true;
  return i;
}

__forceinline s32 Qsort(Thread* t, Move* m, s32 n) {
  s32 i = 0, high = -INF;
  Move* mov;
  for (; n > OO; n--) {
    mov = m - n;
    if (!mov->status && mov->score > high) {
      high = mov->score;
      i = n;
    }
  }
  (m - i)->status = true;
  return i;
}

s32 Qsearch(Thread* t, Move* m, s32 alpha, s32 beta) {
  s32 n, i, mi, type, score;
  u32 fs, ts;
  u64 bb, captures, pieces, aPieces, enemy, empty;
  Move* mov;

  score = mat[wtm] - mat[1 - wtm];
  if (score >= beta) return beta;
  if (score > alpha) alpha = score;

  n = 0;
  bb = 0;
  captures = 0;

  pieces = piece[wtm];
  aPieces = piece[BLACK] | piece[WHITE];
  enemy = aPieces ^ pieces;
  empty = 0xffffffffffffffff ^ aPieces;

  do {
    _BitScanForward64(&fs, pieces);
    pieces ^= one << fs;
    type = board[fs];
    switch (type) {
    case OO: break;
    case WP:
      switch (fs >> 3) {
      case RANK1: break;
      case RANK2:
      case RANK3:
      case RANK4:
      case RANK6:
        bb = wPawnCapts[fs] & enemy;
        break;
      case RANK5:
        bb = wPawnCapts[fs] & (enemy | epbb[ply]);
        type = We;
        break;
      case RANK7:
        bb = (wPawnMoves[fs] & empty) | (wPawnCapts[fs] & enemy);
        captures |= bb;
        while (bb) {
          _BitScanForward64(&ts, bb);
          bb ^= one << ts;
          for (i = Q; i >= B; i--) {
            m->fs = (s32)fs;
            m->ts = (s32)ts;
            m->type = Wb + i;
            m->score = value[board[ts]] - value[board[fs]];
            m->status = false;
            m++;
          }
          n += 4;
        }
        continue;
      }
      break;
    case WN:
    case BN:
      bb = knightMoves[fs] & enemy;
      break;
    case WB:
    case BB:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & bob[fs]
         & enemy;
      break;
    case WR:
    case WRC:
    case BR:
    case BRC:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & rob[fs]
         & enemy;
      break;
    case WQ:
    case BQ:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & enemy;
      break;
    case WK:
    case BK:
    case WC:
    case BC:
      bb = kingMoves[fs] & enemy;
      break;
    case BP:
      switch (fs >> 3) {
      case RANK1:
        break;
      case RANK2:
        bb = (bPawnMoves[fs] & empty) | (bPawnCapts[fs] & enemy);
        captures |= bb;
        while (bb) {
          _BitScanForward64(&ts, bb);
          bb ^= one << ts;
          for (i = Q; i >= B; i--) {
            m->fs = (s32)fs;
            m->ts = (s32)ts;
            m->type = Bb + i;
            m->score = value[board[ts]] - value[board[fs]];
            m->status = false;
            m++;
          }
          n += 4;
        }
        continue;
      case RANK3:
      case RANK5:
      case RANK6:
      case RANK7:
        bb = bPawnCapts[fs] & enemy;
        break;
      case RANK4:
        bb = bPawnCapts[fs] & (enemy | epbb[ply]);
        type = Be;
        break;
      }
      break;
    }

    captures |= bb;

    while (bb) {
      _BitScanForward64(&ts, bb);
      bb ^= one << ts;
      m->fs = (s32)fs;
      m->ts = (s32)ts;
      m->type = type;
      m->score = value[board[ts]] - value[board[fs]];
      m->status = false;
      m++;
      n++;
    }

  } while (pieces);

  if (captures & king[1 - wtm]) return -ILLEGAL;

  for (i = n; i > OO; i--) {
    mi = Qsort(t, m, n);
    mov = (m - mi);
    MakeMove(t, mov);
    mov->score = -Qsearch(t, m, -beta, -alpha);
    TakeBack(t, mov);
    if (mov->score == ILLEGAL) continue;
    if (mov->score > alpha) {
      if (mov->score >= beta) {
        return beta;
      }
      alpha = mov->score;
    }
  }
  return alpha;
}

s32 GenMoves(Thread* t, Move *m) {
  s32 i, type;
  u32 fs, ts, sq;
  u64 bb = 0, captures = 0;
  Move* o = m;

  u64 pieces = piece[wtm];
  u64 aPieces = piece[BLACK] | piece[WHITE];
  u64 enemy = aPieces ^ pieces;
  u64 empty = 0xffffffffffffffff ^ aPieces;
  u64 notme = 0xffffffffffffffff ^ pieces;

  do {
    _BitScanForward64(&fs, pieces);
    pieces ^= one << fs;
    type = board[fs];
    switch (type) {
    case OO:
      break;
    case WP:
      switch (fs >> 3) {
      case RANK1: break;
      case RANK2:
        _BitScanForward64(&sq, wPawnMoves[fs] & aPieces);
        bb = (wPawnMoves[fs] & below[sq]) | (wPawnCapts[fs] & enemy);
        type = Wd;
        break;
      case RANK3:
      case RANK4:
      case RANK6:
        bb = (wPawnMoves[fs] & empty) | (wPawnCapts[fs] & enemy);
        break;
      case RANK5:
        bb = (wPawnMoves[fs] & empty) | (wPawnCapts[fs] & (enemy | epbb[ply]));
        type = We;
        break;
      case RANK7:
        bb = (wPawnMoves[fs] & empty) | (wPawnCapts[fs] & enemy);
        while (bb) {
          _BitScanForward64(&ts, bb);
          bb ^= one << ts;
          for (i = Q; i >= B; i--) {
            m->fs = (s32)fs;
            m->ts = (s32)ts;
            m->type = Wb + i;
            m->score = value[board[ts]] - VP;
            m->status = false;
            m++;
          }
        }
        continue;
      }
      break;
    case WN:
    case BN:
      bb = knightMoves[fs] & notme;
      break;
    case WB:
    case BB:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & bob[fs]
         & notme;
      break;
    case WR:
    case WRC:
    case BR:
    case BRC:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & rob[fs]
         & notme;
      break;
    case WQ:
    case BQ:
      bb = qss[fs][(aPieces >> (fs & 56)) & 127][0]
         & qss[fs][(aPieces >>  8) & 255][1]
         & qss[fs][(aPieces >> 16) & 255][2]
         & qss[fs][(aPieces >> 24) & 255][3]
         & qss[fs][(aPieces >> 32) & 255][4]
         & qss[fs][(aPieces >> 40) & 255][5]
         & qss[fs][(aPieces >> 48) & 255][6]
         & notme;
      break;
    case WK:
    case BK:
      bb = kingMoves[fs] & notme;
      break;
    case WC:
      bb = kingMoves[fs] & notme;
      if (board[H1] == WRC && !(WOCCS & aPieces) && !AtkByBlack(t, WATKS)) {
        m->fs = E1;
        m->ts = G1;
        m->type = WS;
        m->score = 40;
        m->status = false;
        m++;
      }
      if (board[A1] == WRC && !(WOCCL & aPieces) && !AtkByBlack(t, WATKL)) {
        m->fs = E1;
        m->ts = C1;
        m->type = WL;
        m->score = 40;
        m->status = false;
        m++;
      }
      break;
    case BP:
      switch (fs >> 3) {
      case RANK1:
        break;
      case RANK2:
        bb = (bPawnMoves[fs] & empty) | (bPawnCapts[fs] & enemy);
        while (bb) {
          _BitScanForward64(&ts, bb);
          bb ^= one << ts;
          for (i = Q; i >= B; i--) {
            m->fs = (s32)fs;
            m->ts = (s32)ts;
            m->type = Bb + i;
            m->score = value[board[ts]] - VP;
            m->status = false;
            m++;
          }
        }  
        continue;
      case RANK3:
      case RANK5:
      case RANK6:
        bb = (bPawnMoves[fs] & empty) | (bPawnCapts[fs] & enemy);
        break;
      case RANK4:
        bb = (bPawnMoves[fs] & empty) | (bPawnCapts[fs] & (enemy | epbb[ply]));
        type = Be;
        break;
      case RANK7:
        _BitScanReverse64(&sq, bPawnMoves[fs] & aPieces);
        bb = (bPawnMoves[fs] & above[sq]) | (bPawnCapts[fs] & enemy);
        type = Bd;
        break;
      }
      break;
    case BC:
      bb = kingMoves[fs] & notme;
      if (board[H8] == BRC && !(BOCCS & aPieces) && !AtkByWhite(t, BATKS)) {
        m->fs = E8;
        m->ts = G8;
        m->type = BS;
        m->score = 40;
        m->status = false;
        m++;
      }
      if (board[A8] == BRC && !(BOCCL & aPieces) && !AtkByWhite(t, BATKL)) {
        m->fs = E8;
        m->ts = C8;
        m->type = BL;
        m->score = 40;
        m->status = false;
        m++;
      }
      break;
    }

    captures |= bb;

    while (bb) {
      _BitScanForward64(&ts, bb);
      bb ^= one << ts;
      m->fs = (s32)fs;
      m->ts = (s32)ts;
      m->type = type;
      m->score = value[board[m->ts]] - value[board[m->fs]];
      m->status = false;
      m++;
    }

  } while (pieces);

  if (captures & king[1 - wtm]) return false;

  m->status = STOP;

  return (u32)(m - o);
}

s32 Search(Thread* t, Move* m, s32 alpha, s32 beta, s32 depth) {
  s32 i, mi, n, score;

  if (depth < 1) return Qsearch(t, m, alpha, beta);
  n = GenMoves(t, m);
  if (!n) return -ILLEGAL;
  m += n;
  for (i = n; i > 0; i-- ) {
    mi = Sort(t, m, n);
    MakeMove(t, m - mi);
    score = -Search(t, m + 1, -beta, -alpha, depth - 1);
    TakeBack(t, m - mi);
    if (score == ILLEGAL) continue;
    if (score >= beta) return beta;
    if (score > alpha) alpha = score;
  }
  return alpha;
}

void Bricabrac(Thread* t) {
  Search(t, &move[0], -INF, INF, sd);
  bricabrac = MOVE;
}

void GetCmd(Thread* t) {
  s32 i, fs, ts;
  char data[256],  mvstr[20];
  bool match;

  match = false;

  PrintBoard(t);

  fgets(data, 256, stdin);
  _strlwr_s(data);

  std::cout << std::endl;

  if (data[0] >= 'a' && data[0] <= 'h' &&
    data[1] >= '1' && data[1] <= '8' &&
    data[2] >= 'a' && data[2] <= 'h' &&
    data[3] >= '1' && data[3] <= '8') {
    GenMoves(t, &move[0]);
    match = false;
    for (i = 0; move[i].status != STOP; i++) {
      fs = move[i].fs;
      ts = move[i].ts;
      sprintf_s(mvstr, 20, "%c%d%c%d\n", (fs & 7) + 'a', (fs >> 3) + 1, (ts & 7) + 'a', (ts >> 3) + 1);
      if (!strcmp(data, mvstr)) {
        match = true;
        gameMoves[gamePly].fs = fs;
        gameMoves[gamePly].ts = ts;
        gameMoves[gamePly].type = move[i].type;
        MakeMove(t, &gameMoves[gamePly]);
        gamePly++;
        ply--;
      }
      if (match == true) return;
    }
  }

  if (!strcmp(data, "go\n")) {
    bricabrac = BRICABRAC;
    return;
  }

  if (!strcmp(data, "u\n") || !strcmp(data, "undo\n")) {
    gamePly--;
    ply++;
    TakeBack(t, &gameMoves[gamePly]);
    return;
  }
}

void DoMove(Thread* t) {
  s32 i, j = 0, score = -INF;

  for (i = 0; move[i].status != STOP; i++) {
    if (move[i].score > score) {
      score = move[i].score;
      j = i;
    }
  }

  gameMoves[gamePly].fs = move[j].fs;
  gameMoves[gamePly].ts = move[j].ts;
  gameMoves[gamePly].type = move[j].type;
  MakeMove(t, &gameMoves[gamePly]);
  ply--;
  gamePly++;

  bricabrac = GETCMD;
}

void InitializeQSS() {
  u08 sq, sqr, k, l;
  s08 x, y, dx, dy;
  s32 i;
  u64 b, bb;

  for (sq = 0; sq < 64; sq++) {
    y = sq >> 3;
    x = sq & 7;
    bob[sq] = 0;
    rob[sq] = 0;
    for (i = 0; i < 256; i++) {
      for (k = 0, l = 0; k <= 56; k += 8, l++) {
        bb = 0;
        b = (u64)i << k;
        for (dx = +1, dy = +1; x + dx < +8 && y + dy < +8; dx++, dy++) {
          sqr = (((y + dy) << 3) + x + dx);
          bb |= one << sqr;
          bob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dx = -1, dy = +1; x + dx > -1 && y + dy < +8; dx--, dy++) {
          sqr = (((y + dy) << 3) + x + dx);
          bb |= one << sqr;
          bob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dx = +1, dy = -1; x + dx < +8 && y + dy > -1; dx++, dy--) {
          sqr = (((y + dy) << 3) + x + dx);
          bb |= one << sqr;
          bob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dx = -1, dy = -1; x + dx > -1 && y + dy > -1; dx--, dy--) {
          sqr = (((y + dy) << 3) + x + dx);
          bb |= one << sqr;
          bob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dx = -1; x + dx > -1; dx--) {
          sqr = (y << 3) + x + dx;
          bb |= one << sqr;
          rob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dx = +1; x + dx < +8; dx++) {
          sqr = (y << 3) + x + dx;
          bb |= one << sqr;
          rob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dy = +1; y + dy < +8; dy++) {
          sqr = ((y + dy) << 3) + x;
          bb |= one << sqr;
          rob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        for (dy = -1; y + dy > -1; dy--) {
          sqr = ((y + dy) << 3) + x;
          bb |= one << sqr;
          rob[sq] |= one << sqr;
          if ((one << sqr) & b) break;
        }
        qss[sq][i][l] = bb;
      }
    }
  }
}

void InitializeRNK() {
  u08 sq, sqr, i;
  s08 x, y, dx, dy;
  u64 bb, b;

  for (sq = 0; sq < 64; sq++) {
    y = sq >> 3;
    x = sq & 7;
    for (i = 0; i < 128; i++) {
      bb = 0;
      b = (u64)i << (sq & 56);
      for (dx = +1, dy = +1; x + dx < +8 && y + dy < +8; dx++, dy++) {
        sqr = (((y + dy) << 3) + x + dx);
        bb |= one << sqr;
        bob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dx = -1, dy = +1; x + dx > -1 && y + dy < +8; dx--, dy++) {
        sqr = (((y + dy) << 3) + x + dx);
        bb |= one << sqr;
        bob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dx = +1, dy = -1; x + dx < +8 && y + dy > -1; dx++, dy--) {
        sqr = (((y + dy) << 3) + x + dx);
        bb |= one << sqr;
        bob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dx = -1, dy = -1; x + dx > -1 && y + dy > -1; dx--, dy--) {
        sqr = (((y + dy) << 3) + x + dx);
        bb |= one << sqr;
        bob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dx = -1; x + dx > -1; dx--) {
        sqr = (y << 3) + x + dx;
        bb |= one << sqr;
        rob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dx = +1; x + dx < +8; dx++) {
        sqr = (y << 3) + x + dx;
        bb |= one << sqr;
        rob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dy = +1; y + dy < +8; dy++) {
        sqr = ((y + dy) << 3) + x;
        bb |= one << sqr;
        rob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      for (dy = -1; y + dy > -1; dy--) {
        sqr = ((y + dy) << 3) + x;
        bb |= one << sqr;
        rob[sq] |= one << sqr;
        if ((one << sqr) & b) break;
      }
      qss[sq][i][0] = bb;
    }
  }
}

void InitPieceBB() {
  s32 sq, x, y;

  above[0] = 0xffffffffffffffff;
  below[0] = 0xffffffffffffffff;

  for (sq = A1; sq <= H8; sq++) {
    x = sq & 7;
    y = sq >> 3;

    above[sq + 1] = ((0xffffffffffffffff >> (sq +1)) ^ 1) << (sq + 1);
    below[sq + 1] = ((0xffffffffffffffff >> (sq + 1)) << (sq + 1)) ^ 0xffffffffffffffff;

    wPawnMoves[sq] = 0;
    wPawnCapts[sq] = 0;
    bPawnMoves[sq] = 0;
    bPawnCapts[sq] = 0;
    if (sq > H1 && sq < A8) {
      // White Pawn Moves
      wPawnMoves[sq] |= one << (sq + 8);
      if (sq < A3) wPawnMoves[sq] |= one << (sq + 16);
      // White Pawn Captures
      if (x + 1 < +8) wPawnCapts[sq] |= one << (sq + 9);
      if (x - 1 > -1) wPawnCapts[sq] |= one << (sq + 7);
      // Black Pawn Moves
      bPawnMoves[sq] |= one << (sq - 8);
      if (sq > H6) bPawnMoves[sq] |= one << (sq - 16);
      // Black Pawn Captures
      if (x + 1 < +8) bPawnCapts[sq] |= one << (sq - 7);
      if (x - 1 > -1) bPawnCapts[sq] |= one << (sq - 9);
    }
    // Knight Moves
    knightMoves[sq] = 0;
    if (y + 2 < +8 && x + 1 < +8) knightMoves[sq] |= one << (sq + 17);
    if (y + 1 < +8 && x + 2 < +8) knightMoves[sq] |= one << (sq + 10);
    if (y - 1 > -1 && x + 2 < +8) knightMoves[sq] |= one << (sq - +6);
    if (y - 2 > -1 && x + 1 < +8) knightMoves[sq] |= one << (sq - 15);
    if (y - 2 > -1 && x - 1 > -1) knightMoves[sq] |= one << (sq - 17);
    if (y - 1 > -1 && x - 2 > -1) knightMoves[sq] |= one << (sq - 10);
    if (y + 1 < +8 && x - 2 > -1) knightMoves[sq] |= one << (sq + +6);
    if (y + 2 < +8 && x - 1 > -1) knightMoves[sq] |= one << (sq + 15);
    // King Moves
    kingMoves[sq] = 0;
    if (y + 1 < +8) kingMoves[sq] |= one << (sq + 8);
    if (y - 1 > -1) kingMoves[sq] |= one << (sq - 8);
    if (x + 1 < +8) kingMoves[sq] |= one << (sq + 1);
    if (x - 1 > -1) kingMoves[sq] |= one << (sq - 1);
    if (y + 1 < +8 && x + 1 < +8) kingMoves[sq] |= one << (sq + 9);
    if (y - 1 > -1 && x + 1 < +8) kingMoves[sq] |= one << (sq - 7);
    if (y - 1 > -1 && x - 1 > -1) kingMoves[sq] |= one << (sq - 9);
    if (y + 1 < +8 && x - 1 > -1) kingMoves[sq] |= one << (sq + 7);
  }
  InitializeQSS();
  InitializeRNK();
}

void NewGame(Thread* t) {
  LoadFen(t, startFen);
}

void Initialize() {
  bricabrac = GETCMD;
  gamePly = OO;
  sd = 8;
  wtm = WHITE;
  ply = OO;
  InitPieceBB();
  NewGame(t);
}

s32 main() {

  t = &thread;

  Initialize();

  do {
    if (bricabrac == BRICABRAC) Bricabrac(t);
    if (bricabrac == MOVE) DoMove(t);
    GetCmd(t);
  } while (bricabrac);

  return 0;
}

[Mike Sherwin]

Going back to my last working sources and going to try and be more careful this time.

[Uri Blass]

When did "giving up" become an option?

I'm tired of explaining this but for those that have not heard it before. I was born with a learning disability. I guess more accurately a memory disability. I can't remember from one minute to the next what I am doing especially when I lose focus. And when I wake up in the morning most of the previous day is gone. It took me about 30 years to write RomiChess. Many starts and stops. Many times I gave up. Then sometime in 2003 or 2004 I quit my pizza delivery job to write RomiChess. I almost failed again. My savings were gone. I only had $7 dollars left when I released RomiChess on Leo Dicksman's site in June of 2005. That is how close to failure I came once again but somehow ... .

It is even harder this time as I'm even older, 63, so I really could use some help debugging what I have so far or giving up for the last time is a real possibility as I do not have another 30 years.

I think most people are with a memory disability.
For example if you ask somebody what he did 234 days ago you will usuaully get the reply
"I do not remember"

Even memorizing the last minute is something most people cannot do and I can easily prove it.
Give people to look at a number of 50 random digits for a minute and after the minute see how many of them can memorize the number.

Most will not be able even to memorize most of the digits so most of what happened in the last minute is gone.

I doubt if you really memorize less than other people and I think that what you consider "can't remember..." is not really not memorizing but not having access to the memory(if you think that you forgot something but later remember what you think that you forgot then it is clear that the memory was always in your brain but you did not have access to it).

[TommyTC]

Hi Mike,

Another bug.

After either side castles, some legal moves are disallowed, and some illegal moves are allowed.

Analysis:

In MakeMove, the 4 castling moves (WS, WL, BS, BL) fail to update king[WHITE] or king[BLACK] for both the "from" and "to" locations.

Fix:

For WS and WL insert the following:

king[WHITE] ^= one << m->fs;
king[WHITE] ^= one << m->ts;

For BS and BL insert the following:

king[BLACK] ^= one << m->fs;
king[BLACK] ^= one << m->ts;

TakeBack needs the same changes.

Tommy