extern void abort(void); extern void __assert_fail(const char *, const char *, unsigned int, const char *) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__noreturn__)); void reach_error() { __assert_fail("0", "double_req_bl_1072d.c", 3, "reach_error"); } typedef int __int32_t; typedef unsigned int __uint32_t; typedef union { double value; struct { __uint32_t lsw; __uint32_t msw; } parts; } ieee_double_shape_type; // nan check for doubles int isnan_double(double x) { return x != x; } double trunc_double(double x) { int signbit; int msw; unsigned int lsw; int exponent_less_1023; do { ieee_double_shape_type ew_u; ew_u.value = (x); (msw) = ew_u.parts.msw; (lsw) = ew_u.parts.lsw; } while (0); signbit = msw & 0x80000000; exponent_less_1023 = ((msw & 0x7ff00000) >> 20) - 1023; if (exponent_less_1023 < 20) { if (exponent_less_1023 < 0) { do { ieee_double_shape_type iw_u; iw_u.parts.msw = (signbit); iw_u.parts.lsw = (0); (x) = iw_u.value; } while (0); } else { do { ieee_double_shape_type iw_u; iw_u.parts.msw = (signbit | (msw & ~(0x000fffff >> exponent_less_1023))); iw_u.parts.lsw = (0); (x) = iw_u.value; } while (0); } } else if (exponent_less_1023 > 51) { if (exponent_less_1023 == 1024) { return x + x; } } else { do { ieee_double_shape_type iw_u; iw_u.parts.msw = (msw); iw_u.parts.lsw = (lsw & ~(0xffffffffu >> (exponent_less_1023 - 20))); (x) = iw_u.value; } while (0); } return x; } // infinity check for doubles int isinf_double(double x) { __int32_t hx, lx; do { ieee_double_shape_type ew_u; ew_u.value = (x); (hx) = ew_u.parts.msw; (lx) = ew_u.parts.lsw; } while (0); hx &= 0x7fffffff; hx |= (__uint32_t)(lx | (-lx)) >> 31; hx = 0x7ff00000 - hx; return 1 - (int)((__uint32_t)(hx | (-hx)) >> 31); } int main() { /* REQ-BL-1072 * The trunc and truncf procedures shall return the argument, if the argument * x is +-0 or +-Inf . */ double x = -1.0 / 0.0; // INF double res = trunc_double(x); // x is -inf, result shall be x. if (!isinf_double(res)) { {reach_error();} return 1; } return 0; }