| /**************************************************************** |
| |
| The author of this software is David M. Gay. |
| |
| Copyright (C) 1998 by Lucent Technologies |
| All Rights Reserved |
| |
| Permission to use, copy, modify, and distribute this software and |
| its documentation for any purpose and without fee is hereby |
| granted, provided that the above copyright notice appear in all |
| copies and that both that the copyright notice and this |
| permission notice and warranty disclaimer appear in supporting |
| documentation, and that the name of Lucent or any of its entities |
| not be used in advertising or publicity pertaining to |
| distribution of the software without specific, written prior |
| permission. |
| |
| LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, |
| INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. |
| IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY |
| SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER |
| IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, |
| ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF |
| THIS SOFTWARE. |
| |
| ****************************************************************/ |
| |
| /* Please send bug reports to |
| David M. Gay |
| Bell Laboratories, Room 2C-463 |
| 600 Mountain Avenue |
| Murray Hill, NJ 07974-0636 |
| U.S.A. |
| dmg@bell-labs.com |
| */ |
| |
| #include "gdtoaimp.h" |
| #include <string.h> |
| |
| char * |
| #ifdef KR_headers |
| g_ddfmt(buf, dd, ndig, bufsize) char *buf; double *dd; int ndig; unsigned bufsize; |
| #else |
| g_ddfmt(char *buf, double *dd, int ndig, unsigned bufsize) |
| #endif |
| { |
| FPI fpi; |
| char *b, *s, *se; |
| ULong *L, bits0[4], *bits, *zx; |
| int bx, by, decpt, ex, ey, i, j, mode; |
| Bigint *x, *y, *z; |
| double ddx[2]; |
| |
| if (bufsize < 10 || bufsize < ndig + 8) |
| return 0; |
| |
| L = (ULong*)dd; |
| if ((L[_0] & 0x7ff00000L) == 0x7ff00000L) { |
| /* Infinity or NaN */ |
| if (L[_0] & 0xfffff || L[_1]) { |
| nanret: |
| return strcp(buf, "NaN"); |
| } |
| if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) { |
| if (L[2+_0] & 0xfffff || L[2+_1]) |
| goto nanret; |
| if ((L[_0] ^ L[2+_0]) & 0x80000000L) |
| goto nanret; /* Infinity - Infinity */ |
| } |
| infret: |
| b = buf; |
| if (L[_0] & 0x80000000L) |
| *b++ = '-'; |
| return strcp(b, "Infinity"); |
| } |
| if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) { |
| L += 2; |
| if (L[_0] & 0xfffff || L[_1]) |
| goto nanret; |
| goto infret; |
| } |
| if (dd[0] + dd[1] == 0.) { |
| b = buf; |
| #ifndef IGNORE_ZERO_SIGN |
| if (L[_0] & L[2+_0] & 0x80000000L) |
| *b++ = '-'; |
| #endif |
| *b++ = '0'; |
| *b = 0; |
| return b; |
| } |
| if ((L[_0] & 0x7ff00000L) < (L[2+_0] & 0x7ff00000L)) { |
| ddx[1] = dd[0]; |
| ddx[0] = dd[1]; |
| dd = ddx; |
| L = (ULong*)dd; |
| } |
| z = d2b(dd[0], &ex, &bx); |
| if (dd[1] == 0.) |
| goto no_y; |
| x = z; |
| y = d2b(dd[1], &ey, &by); |
| if ( (i = ex - ey) !=0) { |
| if (i > 0) { |
| x = lshift(x, i); |
| ex = ey; |
| } |
| else |
| y = lshift(y, -i); |
| } |
| if ((L[_0] ^ L[2+_0]) & 0x80000000L) { |
| z = diff(x, y); |
| if (L[_0] & 0x80000000L) |
| z->sign = 1 - z->sign; |
| } |
| else { |
| z = sum(x, y); |
| if (L[_0] & 0x80000000L) |
| z->sign = 1; |
| } |
| Bfree(x); |
| Bfree(y); |
| no_y: |
| bits = zx = z->x; |
| for(i = 0; !*zx; zx++) |
| i += 32; |
| i += lo0bits(zx); |
| if (i) { |
| rshift(z, i); |
| ex += i; |
| } |
| fpi.nbits = z->wds * 32 - hi0bits(z->x[j = z->wds-1]); |
| if (fpi.nbits < 106) { |
| fpi.nbits = 106; |
| if (j < 3) { |
| for(i = 0; i <= j; i++) |
| bits0[i] = bits[i]; |
| while(i < 4) |
| bits0[i++] = 0; |
| bits = bits0; |
| } |
| } |
| mode = 2; |
| if (ndig <= 0) { |
| if (bufsize < (int)(fpi.nbits * .301029995664) + 10) { |
| Bfree(z); |
| return 0; |
| } |
| mode = 0; |
| } |
| fpi.emin = 1-1023-53+1; |
| fpi.emax = 2046-1023-106+1; |
| fpi.rounding = FPI_Round_near; |
| fpi.sudden_underflow = 0; |
| i = STRTOG_Normal; |
| s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se); |
| b = g__fmt(buf, s, se, decpt, z->sign); |
| Bfree(z); |
| return b; |
| } |