1 /* $OpenBSD: ldtoa.c,v 1.1 2008/09/07 20:36:08 martynas Exp $ */ 2 /*- 3 * Copyright (c) 2003 David Schultz <das (at) FreeBSD.ORG> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/types.h> 29 #ifndef __vax__ 30 #include <machine/ieee.h> 31 #endif /* !__vax__ */ 32 #include <float.h> 33 #include <inttypes.h> 34 #include <limits.h> 35 #include <math.h> 36 #include <stdlib.h> 37 #include "gdtoaimp.h" 38 39 #if (LDBL_MANT_DIG > DBL_MANT_DIG) 40 41 /* 42 * ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(), 43 * except that the floating point argument is passed by reference. 44 * When dtoa() is passed a NaN or infinity, it sets expt to 9999. 45 * However, a long double could have a valid exponent of 9999, so we 46 * use INT_MAX in ldtoa() instead. 47 */ 48 char * 49 __ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, 50 char **rve) 51 { 52 FPI fpi = { 53 LDBL_MANT_DIG, /* nbits */ 54 LDBL_MIN_EXP - LDBL_MANT_DIG, /* emin */ 55 LDBL_MAX_EXP - LDBL_MANT_DIG, /* emax */ 56 FLT_ROUNDS, /* rounding */ 57 #ifdef Sudden_Underflow /* unused, but correct anyway */ 58 1 59 #else 60 0 61 #endif 62 }; 63 int be, kind; 64 char *ret; 65 struct ieee_ext *p = (struct ieee_ext *)ld; 66 uint32_t bits[(LDBL_MANT_DIG + 31) / 32]; 67 void *vbits = bits; 68 69 /* 70 * gdtoa doesn't know anything about the sign of the number, so 71 * if the number is negative, we need to swap rounding modes of 72 * 2 (upwards) and 3 (downwards). 73 */ 74 *sign = p->ext_sign; 75 fpi.rounding ^= (fpi.rounding >> 1) & p->ext_sign; 76 77 be = p->ext_exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1); 78 EXT_TO_ARRAY32(p, bits); 79 80 switch (fpclassify(*ld)) { 81 case FP_NORMAL: 82 kind = STRTOG_Normal; 83 #ifdef EXT_IMPLICIT_NBIT 84 bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32); 85 #endif /* EXT_IMPLICIT_NBIT */ 86 break; 87 case FP_ZERO: 88 kind = STRTOG_Zero; 89 break; 90 case FP_SUBNORMAL: 91 kind = STRTOG_Denormal; 92 be++; 93 break; 94 case FP_INFINITE: 95 kind = STRTOG_Infinite; 96 break; 97 case FP_NAN: 98 kind = STRTOG_NaN; 99 break; 100 default: 101 abort(); 102 } 103 104 ret = gdtoa(&fpi, be, vbits, &kind, mode, ndigits, decpt, rve); 105 if (*decpt == -32768) 106 *decpt = INT_MAX; 107 return ret; 108 } 109 110 #else /* (LDBL_MANT_DIG == DBL_MANT_DIG) */ 111 112 char * 113 __ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, 114 char **rve) 115 { 116 char *ret; 117 118 ret = dtoa((double)*ld, mode, ndigits, decpt, sign, rve); 119 if (*decpt == 9999) 120 *decpt = INT_MAX; 121 return ret; 122 } 123 124 #endif /* (LDBL_MANT_DIG == DBL_MANT_DIG) */ 125
