1 /* $NetBSD: ldtoa.c,v 1.4.2.1 2007/05/07 19:49:06 pavel Exp $ */ 2 3 /*- 4 * Copyright (c) 2003 David Schultz <das (at) FreeBSD.ORG> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 #include <LibConfig.h> 29 #include <sys/EfiCdefs.h> 30 31 #include <float.h> 32 #include <inttypes.h> 33 #include <limits.h> 34 #include <math.h> 35 #include <stdlib.h> 36 #include <machine/ieee.h> 37 #include "gdtoaimp.h" 38 39 #if defined(_MSC_VER) 40 /* Disable warnings about conversions to narrower data types, 41 primarily for the fpclassify() macro. 42 */ 43 #pragma warning ( disable : 4244 ) 44 // Squelch bogus warnings about uninitialized variable use. 45 #pragma warning ( disable : 4700 ) 46 #endif 47 48 /* 49 * ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(), 50 * except that the floating point argument is passed by reference. 51 * When dtoa() is passed a NaN or infinity, it sets expt to 9999. 52 * However, a long double could have a valid exponent of 9999, so we 53 * use INT_MAX in ldtoa() instead. 54 */ 55 char * 56 ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, char **rve) 57 { 58 #ifdef EXT_EXPBITS 59 static FPI fpi = { 60 LDBL_MANT_DIG, /* nbits */ 61 LDBL_MIN_EXP - LDBL_MANT_DIG, /* emin */ 62 LDBL_MAX_EXP - LDBL_MANT_DIG, /* emax */ 63 FPI_Round_near, /* rounding */ 64 #ifdef Sudden_Underflow /* unused, but correct anyway */ 65 1 66 #else 67 0 68 #endif 69 }; 70 int be, kind; 71 char *ret; 72 union ieee_ext_u u; 73 uint32_t bits[(LDBL_MANT_DIG + 31) / 32]; 74 75 u.extu_ld = *ld; 76 *sign = (int)(u.extu_ext.ext_sign); 77 be = (int)(u.extu_ext.ext_exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1)); 78 EXT_TO_ARRAY32(u, bits); 79 80 switch (fpclassify(u.extu_ld)) { 81 case FP_NORMAL: 82 kind = STRTOG_Normal; 83 #ifdef LDBL_IMPLICIT_NBIT 84 bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32); 85 #endif /* LDBL_IMPLICIT_NBIT */ 86 break; 87 case FP_ZERO: 88 kind = STRTOG_Zero; 89 break; 90 case FP_SUBNORMAL: 91 kind = STRTOG_Denormal; 92 #ifdef LDBL_IMPLICIT_NBIT 93 be++; 94 #endif 95 break; 96 case FP_INFINITE: 97 kind = STRTOG_Infinite; 98 break; 99 case FP_NAN: 100 kind = STRTOG_NaN; 101 break; 102 default: 103 abort(); 104 } 105 106 ret = gdtoa(&fpi, be, (ULong *)bits, &kind, mode, ndigits, decpt, rve); 107 if (*decpt == -32768) 108 *decpt = INT_MAX; 109 return ret; 110 #else 111 return dtoa((double)*ld, mode, ndigits, decpt, sign, rve); 112 #endif 113 } 114
