| /* $OpenBSD: ldtoa.c,v 1.2 2014/08/10 02:15:18 guenther Exp $ */ |
| /*- |
| * Copyright (c) 2003 David Schultz <das@FreeBSD.ORG> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <sys/types.h> |
| #ifndef __vax__ |
| #include <machine/ieee.h> |
| #endif /* !__vax__ */ |
| #include <float.h> |
| #include <stdint.h> |
| #include <limits.h> |
| #include <math.h> |
| #include <stdlib.h> |
| #include "gdtoaimp.h" |
| |
| #if (LDBL_MANT_DIG > DBL_MANT_DIG) |
| |
| /* |
| * ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(), |
| * except that the floating point argument is passed by reference. |
| * When dtoa() is passed a NaN or infinity, it sets expt to 9999. |
| * However, a long double could have a valid exponent of 9999, so we |
| * use INT_MAX in ldtoa() instead. |
| */ |
| char * |
| __ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, |
| char **rve) |
| { |
| FPI fpi = { |
| LDBL_MANT_DIG, /* nbits */ |
| LDBL_MIN_EXP - LDBL_MANT_DIG, /* emin */ |
| LDBL_MAX_EXP - LDBL_MANT_DIG, /* emax */ |
| FLT_ROUNDS, /* rounding */ |
| #ifdef Sudden_Underflow /* unused, but correct anyway */ |
| 1 |
| #else |
| 0 |
| #endif |
| }; |
| int be, kind; |
| char *ret; |
| struct ieee_ext *p = (struct ieee_ext *)ld; |
| uint32_t bits[(LDBL_MANT_DIG + 31) / 32]; |
| void *vbits = bits; |
| |
| /* |
| * gdtoa doesn't know anything about the sign of the number, so |
| * if the number is negative, we need to swap rounding modes of |
| * 2 (upwards) and 3 (downwards). |
| */ |
| *sign = p->ext_sign; |
| fpi.rounding ^= (fpi.rounding >> 1) & p->ext_sign; |
| |
| be = p->ext_exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1); |
| EXT_TO_ARRAY32(p, bits); |
| |
| switch (fpclassify(*ld)) { |
| case FP_NORMAL: |
| kind = STRTOG_Normal; |
| #ifdef EXT_IMPLICIT_NBIT |
| bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32); |
| #endif /* EXT_IMPLICIT_NBIT */ |
| break; |
| case FP_ZERO: |
| kind = STRTOG_Zero; |
| break; |
| case FP_SUBNORMAL: |
| kind = STRTOG_Denormal; |
| be++; |
| break; |
| case FP_INFINITE: |
| kind = STRTOG_Infinite; |
| break; |
| case FP_NAN: |
| kind = STRTOG_NaN; |
| break; |
| default: |
| abort(); |
| } |
| |
| ret = gdtoa(&fpi, be, vbits, &kind, mode, ndigits, decpt, rve); |
| if (*decpt == -32768) |
| *decpt = INT_MAX; |
| return ret; |
| } |
| |
| #else /* (LDBL_MANT_DIG == DBL_MANT_DIG) */ |
| |
| char * |
| __ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, |
| char **rve) |
| { |
| char *ret; |
| |
| ret = dtoa((double)*ld, mode, ndigits, decpt, sign, rve); |
| if (*decpt == 9999) |
| *decpt = INT_MAX; |
| return ret; |
| } |
| |
| #endif /* (LDBL_MANT_DIG == DBL_MANT_DIG) */ |