1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 2005 by David M. Gay
6All Rights Reserved
7
8Permission to use, copy, modify, and distribute this software and its
9documentation for any purpose and without fee is hereby granted,
10provided that the above copyright notice appear in all copies and that
11both that the copyright notice and this permission notice and warranty
12disclaimer appear in supporting documentation, and that the name of
13the author or any of his current or former employers not be used in
14advertising or publicity pertaining to distribution of the software
15without specific, written prior permission.
16
17THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
19NO EVENT SHALL THE AUTHOR OR ANY OF HIS CURRENT OR FORMER EMPLOYERS BE
20LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
21DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
22WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
23ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
24SOFTWARE.
25
26****************************************************************/
27
28/* Please send bug reports to David M. Gay (dmg at acm dot org,
29 * with " at " changed at "@" and " dot " changed to "."). */
30
31/* Program to compute quiet NaNs of various precisions (float, */
32/* double, and perhaps long double) on the current system, */
33/* provided the system uses binary IEEE (P754) arithmetic. */
34/* Note that one system's quiet NaN may be a signaling NaN on */
35/* another system. The IEEE arithmetic standards (P754, P854) */
36/* do not specify how to distinguish signaling NaNs from quiet */
37/* ones, and this detail varies across systems. The computed */
38/* NaN values are encoded in #defines for values for an */
39/* unsigned 32-bit integer type, called Ulong below, and */
40/* (for long double) perhaps as unsigned short values. Once */
41/* upon a time, there were PC compilers for Intel CPUs that */
42/* had sizeof(long double) = 10. Are such compilers still */
43/* distributed? */
44
45#include <stdio.h>
46#include "gd_arith.h"
47
48#ifndef Long
49#define Long long
50#endif
51
52typedef unsigned Long Ulong;
53
54#ifdef NO_LONG_LONG
55#undef Gen_ld_QNAN
56#endif
57
58#undef HAVE_IEEE
59#ifdef IEEE_8087
60#define _0 1
61#define _1 0
62#ifdef Gen_ld_QNAN
63#define _3 3
64static int perm[4] = { 0, 1, 2, 3 };
65#endif
66#define HAVE_IEEE
67#endif
68#ifdef IEEE_MC68k
69#define _0 0
70#define _1 1
71#ifdef Gen_ld_QNAN
72#define _3 0
73static int perm[4] = { 3, 2, 1, 0 };
74#endif
75#define HAVE_IEEE
76#endif
77
78#define UL (unsigned long)
79
80#ifdef MINGW_BUILD_GEN
81 int
82main(void)
83{
84#ifdef HAVE_IEEE
85 typedef union {
86 float f;
87 double d;
88 Ulong L[4];
89#ifndef NO_LONG_LONG
90 unsigned short u[5];
91 long double D;
92#endif
93 } U;
94 U a, b, c;
95#ifdef Gen_ld_QNAN
96 int i;
97#endif
98
99 a.L[0] = b.L[0] = 0x7f800000;
100 c.f = a.f - b.f;
101 printf("#define f_QNAN 0x%lx\n", UL (c.L[0] & 0x7fffffff));
102 a.L[_0] = b.L[_0] = 0x7ff00000;
103 a.L[_1] = b.L[_1] = 0;
104 c.d = a.d - b.d; /* quiet NaN */
105 c.L[_0] &= 0x7fffffff;
106 printf("#define d_QNAN0 0x%lx\n", UL c.L[0]);
107 printf("#define d_QNAN1 0x%lx\n", UL c.L[1]);
108#ifdef Gen_ld_QNAN
109 if (sizeof(a.D) >= 16) {
110 b.D = c.D = a.d;
111 if (printf("") < 0)
112 c.D = 37; /* never executed; just defeat optimization */
113 a.L[0] = a.L[1] = a.L[2] = a.L[3] = 0;
114 a.D = b.D - c.D;
115 a.L[_3] &= 0x7fffffff;
116 for(i = 0; i < 4; i++)
117 printf("#define ld_QNAN%d 0x%lx\n", i, UL a.L[perm[i]]);
118 }
119#endif
120#endif /* HAVE_IEEE */
121 return 0;
122 }
123#endif