refactor(magic): moving script to scripts/ folder

1 files changed, 0 insertions, 224 deletions

diff --git a/magic_finder.c b/magic_finder.c
deleted file mode 100644
index ee21587..0000000
--- a/magic_finder.c
+++ /dev/null
@@ -1,224 +0,0 @@
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
-// TODO: make magic bitboards use diffrent shift for each magic number (maybe)
-
-static int popcount(uint64_t b) { return __builtin_popcountll(b); }
-
-static uint64_t computeRookMask(int sq) {
-  uint64_t mask = 0;
-  int r = sq / 8, f = sq % 8;
-  for (int i = r + 1; i < 7; i++)
-    mask |= 1ULL << (i * 8 + f);
-  for (int i = r - 1; i > 0; i--)
-    mask |= 1ULL << (i * 8 + f);
-  for (int j = f + 1; j < 7; j++)
-    mask |= 1ULL << (r * 8 + j);
-  for (int j = f - 1; j > 0; j--)
-    mask |= 1ULL << (r * 8 + j);
-  return mask;
-}
-
-static uint64_t computeBishopMask(int sq) {
-  uint64_t mask = 0;
-  int r = sq / 8, f = sq % 8;
-  for (int i = r + 1, j = f + 1; i < 7 && j < 7; i++, j++)
-    mask |= 1ULL << (i * 8 + j);
-  for (int i = r + 1, j = f - 1; i < 7 && j > 0; i++, j--)
-    mask |= 1ULL << (i * 8 + j);
-  for (int i = r - 1, j = f + 1; i > 0 && j < 7; i--, j++)
-    mask |= 1ULL << (i * 8 + j);
-  for (int i = r - 1, j = f - 1; i > 0 && j > 0; i--, j--)
-    mask |= 1ULL << (i * 8 + j);
-  return mask;
-}
-
-static uint64_t computeRookAttacks(int sq, uint64_t occ) {
-  uint64_t att = 0;
-  int r = sq / 8, f = sq % 8;
-  for (int i = r + 1; i < 8; i++) {
-    att |= 1ULL << (i * 8 + f);
-    if (occ & (1ULL << (i * 8 + f)))
-      break;
-  }
-  for (int i = r - 1; i >= 0; i--) {
-    att |= 1ULL << (i * 8 + f);
-    if (occ & (1ULL << (i * 8 + f)))
-      break;
-  }
-  for (int j = f + 1; j < 8; j++) {
-    att |= 1ULL << (r * 8 + j);
-    if (occ & (1ULL << (r * 8 + j)))
-      break;
-  }
-  for (int j = f - 1; j >= 0; j--) {
-    att |= 1ULL << (r * 8 + j);
-    if (occ & (1ULL << (r * 8 + j)))
-      break;
-  }
-  return att;
-}
-
-static uint64_t computeBishopAttacks(int sq, uint64_t occ) {
-  uint64_t att = 0;
-  int r = sq / 8, f = sq % 8;
-  for (int i = r + 1, j = f + 1; i < 8 && j < 8; i++, j++) {
-    att |= 1ULL << (i * 8 + j);
-    if (occ & (1ULL << (i * 8 + j)))
-      break;
-  }
-  for (int i = r + 1, j = f - 1; i < 8 && j >= 0; i++, j--) {
-    att |= 1ULL << (i * 8 + j);
-    if (occ & (1ULL << (i * 8 + j)))
-      break;
-  }
-  for (int i = r - 1, j = f + 1; i >= 0 && j < 8; i--, j++) {
-    att |= 1ULL << (i * 8 + j);
-    if (occ & (1ULL << (i * 8 + j)))
-      break;
-  }
-  for (int i = r - 1, j = f - 1; i >= 0 && j >= 0; i--, j--) {
-    att |= 1ULL << (i * 8 + j);
-    if (occ & (1ULL << (i * 8 + j)))
-      break;
-  }
-  return att;
-}
-
-static uint64_t mapSquaresToMask(uint64_t index, uint64_t mask) {
-  uint64_t result = 0;
-  int bits = __builtin_popcountll(mask);
-  for (int i = 0; i < bits; i++) {
-    int sq = __builtin_ctzll(mask);
-    mask &= mask - 1;
-    if (index & (1ULL << i))
-      result |= (1ULL << sq);
-  }
-  return result;
-}
-
-static int findMagic(uint64_t mask, uint64_t (*attackFn)(int, uint64_t), int sq,
-                     int shift, uint64_t *outMagic) {
-  int nbits = popcount(mask);
-  uint64_t nocc = 1ULL << nbits;
-
-  uint64_t *occs = malloc(nocc * sizeof(uint64_t));
-  uint64_t *atts = malloc(nocc * sizeof(uint64_t));
-  for (uint64_t i = 0; i < nocc; i++) {
-    occs[i] = mapSquaresToMask(i, mask);
-    atts[i] = attackFn(sq, occs[i]);
-  }
-
-  uint64_t tableSize = 1ULL << (64 - shift);
-  uint64_t *table = malloc(tableSize * sizeof(uint64_t));
-  uint64_t *epoch = calloc(tableSize, sizeof(uint64_t));
-  uint64_t cnt = 0;
-
-  for (unsigned long long attempt = 0; attempt < 10000000000ULL; attempt++) {
-    uint64_t magic;
-    do {
-      magic =
-          ((uint64_t)rand() << 32 | rand()) & ((uint64_t)rand() << 32 | rand());
-    } while (popcount((mask * magic) & 0xFF00000000000000ULL) < 6);
-
-    cnt++;
-    int ok = 1;
-    for (uint64_t i = 0; i < nocc; i++) {
-      uint64_t idx = (occs[i] * magic) >> shift;
-      if (epoch[idx] < cnt) {
-        epoch[idx] = cnt;
-        table[idx] = atts[i];
-      } else if (table[idx] != atts[i]) {
-        ok = 0;
-        break;
-      }
-    }
-    if (ok) {
-      *outMagic = magic;
-      free(occs);
-      free(atts);
-      free(table);
-      free(epoch);
-      return 1;
-    }
-  }
-
-  free(occs);
-  free(atts);
-  free(table);
-  free(epoch);
-  return 0;
-}
-
-int main(int argc, char *argv[]) {
-  int shift = 52;
-  if (argc > 1) {
-    shift = atoi(argv[1]);
-    if (shift < 32 || shift > 63) {
-      fprintf(stderr, "Usage: %s [shift]  (32..63, default 52)\n", argv[0]);
-      return 1;
-    }
-  }
-  srand(time(NULL));
-
-  uint64_t rookMags[64], bishopMags[64];
-  uint64_t rookMasks[64], bishopMasks[64];
-
-  fprintf(stderr,
-          "Finding per-square rook magics (shift %d, table size %llu)...\n",
-          shift, (unsigned long long)(1ULL << (64 - shift)));
-  for (int sq = 0; sq < 64; sq++) {
-    rookMasks[sq] = computeRookMask(sq);
-    if (!findMagic(rookMasks[sq], computeRookAttacks, sq, shift,
-                   &rookMags[sq])) {
-      fprintf(stderr, "FAILED to find rook magic for square %d\n", sq);
-      return 1;
-    }
-    fprintf(stderr, "  sq %2d: %d bits, magic 0x%016llx\n", sq,
-            popcount(rookMasks[sq]), (unsigned long long)rookMags[sq]);
-  }
-
-  fprintf(stderr, "\nFinding per-square bishop magics (shift %d)...\n", shift);
-  for (int sq = 0; sq < 64; sq++) {
-    bishopMasks[sq] = computeBishopMask(sq);
-    if (!findMagic(bishopMasks[sq], computeBishopAttacks, sq, shift,
-                   &bishopMags[sq])) {
-      fprintf(stderr, "FAILED to find bishop magic for square %d\n", sq);
-      return 1;
-    }
-    fprintf(stderr, "  sq %2d: %d bits, magic 0x%016llx\n", sq,
-            popcount(bishopMasks[sq]), (unsigned long long)bishopMags[sq]);
-  }
-
-  fprintf(stderr, "\nDone! Writing magics.txt\n");
-
-  FILE *f = fopen("magics.txt", "w");
-  if (!f) {
-    fprintf(stderr, "Cannot open magics.txt\n");
-    return 1;
-  }
-
-  fprintf(f, "// shift = %d\n", shift);
-  fprintf(f, "constexpr int MAGIC_SHIFT = %d;\n\n", shift);
-
-  fprintf(f, "constexpr std::array<uint64_t, 64> rookMagics = {\n");
-  for (int i = 0; i < 64; i++) {
-    fprintf(f, "    0x%016llxULL%c // %c%d\n", (unsigned long long)rookMags[i],
-            i < 63 ? ',' : ' ', 'a' + i % 8, i / 8 + 1);
-  }
-  fprintf(f, "};\n\n");
-
-  fprintf(f, "constexpr std::array<uint64_t, 64> bishopMagics = {\n");
-  for (int i = 0; i < 64; i++) {
-    fprintf(f, "    0x%016llxULL%c // %c%d\n",
-            (unsigned long long)bishopMags[i], i < 63 ? ',' : ' ', 'a' + i % 8,
-            i / 8 + 1);
-  }
-  fprintf(f, "};\n");
-
-  fclose(f);
-  return 0;
-}