1/*  $NetBSD: ldtoa.c,v 1.4.2.1 2007/05/07 19:49:06 pavel Exp $  */
2
3/*-
4 * Copyright (c) 2003 David Schultz <das@FreeBSD.ORG>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28#include  <LibConfig.h>
29#include <sys/EfiCdefs.h>
30
31#include <float.h>
32#include <inttypes.h>
33#include <limits.h>
34#include <math.h>
35#include <stdlib.h>
36#include <machine/ieee.h>
37#include "gdtoaimp.h"
38
39#if defined(_MSC_VER)
40  /*  Disable warnings about conversions to narrower data types,
41      primarily for the fpclassify() macro.
42  */
43  #pragma warning ( disable : 4244 )
44  // Squelch bogus warnings about uninitialized variable use.
45  #pragma warning ( disable : 4700 )
46#endif
47
48/*
49 * ldtoa() is a wrapper for gdtoa() that makes it smell like dtoa(),
50 * except that the floating point argument is passed by reference.
51 * When dtoa() is passed a NaN or infinity, it sets expt to 9999.
52 * However, a long double could have a valid exponent of 9999, so we
53 * use INT_MAX in ldtoa() instead.
54 */
55char *
56ldtoa(long double *ld, int mode, int ndigits, int *decpt, int *sign, char **rve)
57{
58#ifdef EXT_EXPBITS
59  static FPI fpi = {
60    LDBL_MANT_DIG,      /* nbits */
61    LDBL_MIN_EXP - LDBL_MANT_DIG, /* emin */
62    LDBL_MAX_EXP - LDBL_MANT_DIG, /* emax */
63    FPI_Round_near,           /* rounding */
64#ifdef Sudden_Underflow /* unused, but correct anyway */
65    1
66#else
67    0
68#endif
69  };
70  int be, kind;
71  char *ret;
72  union ieee_ext_u u;
73  uint32_t bits[(LDBL_MANT_DIG + 31) / 32];
74
75  u.extu_ld = *ld;
76  *sign = (int)(u.extu_ext.ext_sign);
77  be = (int)(u.extu_ext.ext_exp - (LDBL_MAX_EXP - 1) - (LDBL_MANT_DIG - 1));
78  EXT_TO_ARRAY32(u, bits);
79
80  switch (fpclassify(u.extu_ld)) {
81  case FP_NORMAL:
82    kind = STRTOG_Normal;
83#ifdef  LDBL_IMPLICIT_NBIT
84    bits[LDBL_MANT_DIG / 32] |= 1 << ((LDBL_MANT_DIG - 1) % 32);
85#endif /* LDBL_IMPLICIT_NBIT */
86    break;
87  case FP_ZERO:
88    kind = STRTOG_Zero;
89    break;
90  case FP_SUBNORMAL:
91    kind = STRTOG_Denormal;
92#ifdef  LDBL_IMPLICIT_NBIT
93    be++;
94#endif
95    break;
96  case FP_INFINITE:
97    kind = STRTOG_Infinite;
98    break;
99  case FP_NAN:
100    kind = STRTOG_NaN;
101    break;
102  default:
103    abort();
104  }
105
106  ret = gdtoa(&fpi, be, (ULong *)bits, &kind, mode, ndigits, decpt, rve);
107  if (*decpt == -32768)
108    *decpt = INT_MAX;
109  return ret;
110#else
111  return dtoa((double)*ld, mode, ndigits, decpt, sign, rve);
112#endif
113}
114