floatunditf_ieee754.c revision 1.1.4.2
1 1.1.4.2 yamt /* $NetBSD: floatunditf_ieee754.c,v 1.1.4.2 2014/05/22 11:36:52 yamt Exp $ */ 2 1.1.4.2 yamt 3 1.1.4.2 yamt /*- 4 1.1.4.2 yamt * Copyright (c) 2014 Joerg Sonnenberger <joerg (at) NetBSD.org>. 5 1.1.4.2 yamt * All rights reserved. 6 1.1.4.2 yamt * 7 1.1.4.2 yamt * Redistribution and use in source and binary forms, with or without 8 1.1.4.2 yamt * modification, are permitted provided that the following conditions 9 1.1.4.2 yamt * are met: 10 1.1.4.2 yamt * 11 1.1.4.2 yamt * 1. Redistributions of source code must retain the above copyright 12 1.1.4.2 yamt * notice, this list of conditions and the following disclaimer. 13 1.1.4.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 14 1.1.4.2 yamt * notice, this list of conditions and the following disclaimer in 15 1.1.4.2 yamt * the documentation and/or other materials provided with the 16 1.1.4.2 yamt * distribution. 17 1.1.4.2 yamt * 18 1.1.4.2 yamt * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 1.1.4.2 yamt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 1.1.4.2 yamt * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21 1.1.4.2 yamt * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22 1.1.4.2 yamt * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 1.1.4.2 yamt * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 1.1.4.2 yamt * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 1.1.4.2 yamt * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 1.1.4.2 yamt * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 1.1.4.2 yamt * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28 1.1.4.2 yamt * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 1.1.4.2 yamt * SUCH DAMAGE. 30 1.1.4.2 yamt */ 31 1.1.4.2 yamt 32 1.1.4.2 yamt #include <sys/cdefs.h> 33 1.1.4.2 yamt __RCSID("$NetBSD: floatunditf_ieee754.c,v 1.1.4.2 2014/05/22 11:36:52 yamt Exp $"); 34 1.1.4.2 yamt 35 1.1.4.2 yamt #include <math.h> 36 1.1.4.2 yamt #include <machine/ieee.h> 37 1.1.4.2 yamt #include <limits.h> 38 1.1.4.2 yamt 39 1.1.4.2 yamt #ifdef __HAVE_LONG_DOUBLE 40 1.1.4.2 yamt 41 1.1.4.2 yamt long double __floatunditf(uint64_t x); 42 1.1.4.2 yamt 43 1.1.4.2 yamt /* 44 1.1.4.2 yamt * Convert uint64_t to long double. 45 1.1.4.2 yamt */ 46 1.1.4.2 yamt long double 47 1.1.4.2 yamt __floatunditf(uint64_t x) 48 1.1.4.2 yamt { 49 1.1.4.2 yamt int exponent, zeros; 50 1.1.4.2 yamt union ieee_ext_u ux; 51 1.1.4.2 yamt 52 1.1.4.2 yamt /* Use the easier conversion routine for uint32_t if possible. */ 53 1.1.4.2 yamt if (x <= UINT32_MAX) 54 1.1.4.2 yamt return (long double)(uint32_t)x; 55 1.1.4.2 yamt 56 1.1.4.2 yamt zeros = __builtin_clzll(x); 57 1.1.4.2 yamt #ifdef LDBL_IMPLICIT_NBIT 58 1.1.4.2 yamt exponent = 64 - zeros; 59 1.1.4.2 yamt x <<= zeros + 1; 60 1.1.4.2 yamt #else 61 1.1.4.2 yamt exponent = 63 - zeros; 62 1.1.4.2 yamt x <<= zeros; 63 1.1.4.2 yamt #endif 64 1.1.4.2 yamt 65 1.1.4.2 yamt ux.extu_exp = EXT_EXP_BIAS + exponent; 66 1.1.4.2 yamt ux.extu_frach = (x >> (64 - EXT_FRACHBITS)); 67 1.1.4.2 yamt x <<= EXT_FRACHBITS; 68 1.1.4.2 yamt #ifdef EXT_FRACHMBITS 69 1.1.4.2 yamt ux.extu_frachm = (x >> (64 - EXT_FRACHMBITS)); 70 1.1.4.2 yamt x <<= EXT_FRACHMBITS; 71 1.1.4.2 yamt #endif 72 1.1.4.2 yamt #ifdef EXT_FRACLMBITS 73 1.1.4.2 yamt ux.extu_fraclm = (x >> (64 - EXT_FRACLMBITS)); 74 1.1.4.2 yamt x <<= EXT_FRACLMBITS; 75 1.1.4.2 yamt #endif 76 1.1.4.2 yamt ux.extu_fracl = (x >> (64 - EXT_FRACLBITS)); 77 1.1.4.2 yamt ux.extu_sign = 0; 78 1.1.4.2 yamt 79 1.1.4.2 yamt return ux.extu_ld; 80 1.1.4.2 yamt } 81 1.1.4.2 yamt #endif /* __HAVE_LONG_DOUBLE */ 82
Indexes created Tue Sep 30 17:09:57 GMT 2025