#include "libm.h" #if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1 #define EPS DBL_EPSILON #elif FLT_EVAL_METHOD==2 #define EPS LDBL_EPSILON #endif static const double_t toint = 1/EPS; double ceil(double x) { union {double f; uint64_t i;} u = {x}; int e = u.i >> 52 & 0x7ff; double_t y; if (e >= 0x3ff+52 || x == 0) return x; /* y = int(x) - x, where int(x) is an integer neighbor of x */ if (u.i >> 63) y = x - toint + toint - x; else y = x + toint - toint - x; /* special case because of non-nearest rounding modes */ if (e <= 0x3ff-1) { FORCE_EVAL(y); return u.i >> 63 ? -0.0 : 1; } if (y < 0) return x + y + 1; return x + y; }