| /* Round to integer type. dbl-64 version. |
| Copyright (C) 2016-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <fenv.h> |
| #include <math.h> |
| #include <math_private.h> |
| #include <libm-alias-double.h> |
| #include <stdbool.h> |
| #include <stdint.h> |
| |
| #define BIAS 0x3ff |
| #define MANT_DIG 53 |
| |
| #if UNSIGNED |
| # define RET_TYPE uintmax_t |
| #else |
| # define RET_TYPE intmax_t |
| #endif |
| |
| #include <fromfp.h> |
| |
| RET_TYPE |
| FUNC (double x, int round, unsigned int width) |
| { |
| if (width > INTMAX_WIDTH) |
| width = INTMAX_WIDTH; |
| uint64_t ix; |
| EXTRACT_WORDS64 (ix, x); |
| bool negative = (ix & 0x8000000000000000ULL) != 0; |
| if (width == 0) |
| return fromfp_domain_error (negative, width); |
| ix &= 0x7fffffffffffffffULL; |
| if (ix == 0) |
| return 0; |
| int exponent = ix >> (MANT_DIG - 1); |
| exponent -= BIAS; |
| int max_exponent = fromfp_max_exponent (negative, width); |
| if (exponent > max_exponent) |
| return fromfp_domain_error (negative, width); |
| |
| ix &= ((1ULL << (MANT_DIG - 1)) - 1); |
| ix |= 1ULL << (MANT_DIG - 1); |
| uintmax_t uret; |
| bool half_bit, more_bits; |
| if (exponent >= MANT_DIG - 1) |
| { |
| uret = ix; |
| uret <<= exponent - (MANT_DIG - 1); |
| half_bit = false; |
| more_bits = false; |
| } |
| else if (exponent >= -1) |
| { |
| uint64_t h = 1ULL << (MANT_DIG - 2 - exponent); |
| half_bit = (ix & h) != 0; |
| more_bits = (ix & (h - 1)) != 0; |
| uret = ix >> (MANT_DIG - 1 - exponent); |
| } |
| else |
| { |
| uret = 0; |
| half_bit = false; |
| more_bits = true; |
| } |
| return fromfp_round_and_return (negative, uret, half_bit, more_bits, round, |
| exponent, max_exponent, width); |
| } |