1 /**************************************************************** 2 3 The author of this software is David M. Gay. 4 5 Copyright (C) 1998 by Lucent Technologies 6 All Rights Reserved 7 8 Permission to use, copy, modify, and distribute this software and 9 its documentation for any purpose and without fee is hereby 10 granted, provided that the above copyright notice appear in all 11 copies and that both that the copyright notice and this 12 permission notice and warranty disclaimer appear in supporting 13 documentation, and that the name of Lucent or any of its entities 14 not be used in advertising or publicity pertaining to 15 distribution of the software without specific, written prior 16 permission. 17 18 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 19 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 20 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 21 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 22 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 23 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 24 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 25 THIS SOFTWARE. 26 27 ****************************************************************/ 28 29 /* Please send bug reports to 30 David M. Gay 31 Bell Laboratories, Room 2C-463 32 600 Mountain Avenue 33 Murray Hill, NJ 07974-0636 34 U.S.A. 35 dmg@bell-labs.com 36 */ 37 38 #include "gdtoaimp.h" 39 #include <string.h> 40 41 char * 42 #ifdef KR_headers 43 g_ddfmt(buf, dd, ndig, bufsize) char *buf; double *dd; int ndig; unsigned bufsize; 44 #else 45 g_ddfmt(char *buf, double *dd, int ndig, unsigned bufsize) 46 #endif 47 { 48 FPI fpi; 49 char *b, *s, *se; 50 ULong *L, bits0[4], *bits, *zx; 51 int bx, by, decpt, ex, ey, i, j, mode; 52 Bigint *x, *y, *z; 53 double ddx[2]; 54 55 if (bufsize < 10 || bufsize < ndig + 8) 56 return 0; 57 58 L = (ULong*)dd; 59 if ((L[_0] & 0x7ff00000L) == 0x7ff00000L) { 60 /* Infinity or NaN */ 61 if (L[_0] & 0xfffff || L[_1]) { 62 nanret: 63 return strcp(buf, "NaN"); 64 } 65 if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) { 66 if (L[2+_0] & 0xfffff || L[2+_1]) 67 goto nanret; 68 if ((L[_0] ^ L[2+_0]) & 0x80000000L) 69 goto nanret; /* Infinity - Infinity */ 70 } 71 infret: 72 b = buf; 73 if (L[_0] & 0x80000000L) 74 *b++ = '-'; 75 return strcp(b, "Infinity"); 76 } 77 if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) { 78 L += 2; 79 if (L[_0] & 0xfffff || L[_1]) 80 goto nanret; 81 goto infret; 82 } 83 if (dd[0] + dd[1] == 0.) { 84 b = buf; 85 #ifndef IGNORE_ZERO_SIGN 86 if (L[_0] & L[2+_0] & 0x80000000L) 87 *b++ = '-'; 88 #endif 89 *b++ = '0'; 90 *b = 0; 91 return b; 92 } 93 if ((L[_0] & 0x7ff00000L) < (L[2+_0] & 0x7ff00000L)) { 94 ddx[1] = dd[0]; 95 ddx[0] = dd[1]; 96 dd = ddx; 97 L = (ULong*)dd; 98 } 99 z = d2b(dd[0], &ex, &bx); 100 if (dd[1] == 0.) 101 goto no_y; 102 x = z; 103 y = d2b(dd[1], &ey, &by); 104 if ( (i = ex - ey) !=0) { 105 if (i > 0) { 106 x = lshift(x, i); 107 ex = ey; 108 } 109 else 110 y = lshift(y, -i); 111 } 112 if ((L[_0] ^ L[2+_0]) & 0x80000000L) { 113 z = diff(x, y); 114 if (L[_0] & 0x80000000L) 115 z->sign = 1 - z->sign; 116 } 117 else { 118 z = sum(x, y); 119 if (L[_0] & 0x80000000L) 120 z->sign = 1; 121 } 122 Bfree(x); 123 Bfree(y); 124 no_y: 125 bits = zx = z->x; 126 for(i = 0; !*zx; zx++) 127 i += 32; 128 i += lo0bits(zx); 129 if (i) { 130 rshift(z, i); 131 ex += i; 132 } 133 fpi.nbits = z->wds * 32 - hi0bits(z->x[j = z->wds-1]); 134 if (fpi.nbits < 106) { 135 fpi.nbits = 106; 136 if (j < 3) { 137 for(i = 0; i <= j; i++) 138 bits0[i] = bits[i]; 139 while(i < 4) 140 bits0[i++] = 0; 141 bits = bits0; 142 } 143 } 144 mode = 2; 145 if (ndig <= 0) { 146 if (bufsize < (int)(fpi.nbits * .301029995664) + 10) { 147 Bfree(z); 148 return 0; 149 } 150 mode = 0; 151 } 152 fpi.emin = 1-1023-53+1; 153 fpi.emax = 2046-1023-106+1; 154 fpi.rounding = FPI_Round_near; 155 fpi.sudden_underflow = 0; 156 i = STRTOG_Normal; 157 s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se); 158 b = g__fmt(buf, s, se, decpt, z->sign); 159 Bfree(z); 160 return b; 161 } 162