#include #include double remquo(double x, double y, int *quo) { union {double f; uint64_t i;} ux = {x}, uy = {y}; int ex = ux.i>>52 & 0x7ff; int ey = uy.i>>52 & 0x7ff; int sx = ux.i>>63; int sy = uy.i>>63; uint32_t q; uint64_t i; uint64_t uxi = ux.i; *quo = 0; if (uy.i<<1 == 0 || isnan(y) || ex == 0x7ff) return (x*y)/(x*y); if (ux.i<<1 == 0) return x; /* normalize x and y */ if (!ex) { for (i = uxi<<12; i>>63 == 0; ex--, i <<= 1); uxi <<= -ex + 1; } else { uxi &= -1ULL >> 12; uxi |= 1ULL << 52; } if (!ey) { for (i = uy.i<<12; i>>63 == 0; ey--, i <<= 1); uy.i <<= -ey + 1; } else { uy.i &= -1ULL >> 12; uy.i |= 1ULL << 52; } q = 0; if (ex < ey) { if (ex+1 == ey) goto end; return x; } /* x mod y */ for (; ex > ey; ex--) { i = uxi - uy.i; if (i >> 63 == 0) { uxi = i; q++; } uxi <<= 1; q <<= 1; } i = uxi - uy.i; if (i >> 63 == 0) { uxi = i; q++; } if (uxi == 0) ex = -60; else for (; uxi>>52 == 0; uxi <<= 1, ex--); end: /* scale result and decide between |x| and |x|-|y| */ if (ex > 0) { uxi -= 1ULL << 52; uxi |= (uint64_t)ex << 52; } else { uxi >>= -ex + 1; } ux.i = uxi; x = ux.f; if (sy) y = -y; if (ex == ey || (ex+1 == ey && (2*x > y || (2*x == y && q%2)))) { x -= y; q++; } q &= 0x7fffffff; *quo = sx^sy ? -(int)q : (int)q; return sx ? -x : x; }