1/* $NetBSD: g_dfmt.c,v 1.2 2008/03/21 23:13:48 christos Exp $ */ 2 3/**************************************************************** 4 5The author of this software is David M. Gay. 6 7Copyright (C) 1998 by Lucent Technologies 8All Rights Reserved 9 10Permission to use, copy, modify, and distribute this software and 11its documentation for any purpose and without fee is hereby 12granted, provided that the above copyright notice appear in all 13copies and that both that the copyright notice and this 14permission notice and warranty disclaimer appear in supporting 15documentation, and that the name of Lucent or any of its entities 16not be used in advertising or publicity pertaining to 17distribution of the software without specific, written prior 18permission. 19 20LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 21INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 22IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 23SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 24WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 25IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 26ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 27THIS SOFTWARE. 28 29****************************************************************/ 30 31/* Please send bug reports to David M. Gay (dmg at acm dot org, 32 * with " at " changed at "@" and " dot " changed to "."). */ 33 34#include "gdtoaimp.h" 35 36 char* 37#ifdef KR_headers 38g_dfmt(buf, d, ndig, bufsize) char *buf; double *d; int ndig; size_t bufsize; 39#else 40g_dfmt(char *buf, double *d, int ndig, size_t bufsize) 41#endif 42{ 43 static FPI fpi0 = { 53, 1-1023-53+1, 2046-1023-53+1, 1, 0 }; 44 char *b, *s, *se; 45 ULong bits[2], *L, sign; 46 int decpt, ex, i, mode; 47#ifdef Honor_FLT_ROUNDS 48#include "gdtoa_fltrnds.h" 49#else 50#define fpi &fpi0 51#endif 52 53 if (ndig < 0) 54 ndig = 0; 55 if (bufsize < ndig + 10) 56 return 0; 57 58 L = (ULong*)d; 59 sign = L[_0] & 0x80000000L; 60 if ((L[_0] & 0x7ff00000) == 0x7ff00000) { 61 /* Infinity or NaN */ 62 if (bufsize < 10) 63 return 0; 64 if (L[_0] & 0xfffff || L[_1]) { 65 return strcp(buf, "NaN"); 66 } 67 b = buf; 68 if (sign) 69 *b++ = '-'; 70 return strcp(b, "Infinity"); 71 } 72 if (L[_1] == 0 && (L[_0] ^ sign) == 0 /*d == 0.*/) { 73 b = buf; 74#ifndef IGNORE_ZERO_SIGN 75 if (L[_0] & 0x80000000L) 76 *b++ = '-'; 77#endif 78 *b++ = '0'; 79 *b = 0; 80 return b; 81 } 82 bits[0] = L[_1]; 83 bits[1] = L[_0] & 0xfffff; 84 if ( (ex = (L[_0] >> 20) & 0x7ff) !=0) 85 bits[1] |= 0x100000; 86 else 87 ex = 1; 88 ex -= 0x3ff + 52; 89 mode = 2; 90 if (ndig <= 0) 91 mode = 0; 92 i = STRTOG_Normal; 93 if (sign) 94 i = STRTOG_Normal | STRTOG_Neg; 95 s = gdtoa(fpi, ex, bits, &i, mode, ndig, &decpt, &se); 96 if (s == NULL) 97 return NULL; 98 return g__fmt(buf, s, se, decpt, sign, bufsize); 99 } 100