1/****************************************************************
2Copyright (C) 1997, 1998 Lucent Technologies
3All Rights Reserved
4
5Permission to use, copy, modify, and distribute this software and
6its documentation for any purpose and without fee is hereby
7granted, provided that the above copyright notice appear in all
8copies and that both that the copyright notice and this
9permission notice and warranty disclaimer appear in supporting
10documentation, and that the name of Lucent or any of its entities
11not be used in advertising or publicity pertaining to
12distribution of the software without specific, written prior
13permission.
14
15LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
16INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
17IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
18SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
20IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
21ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
22THIS SOFTWARE.
23****************************************************************/
24
25/* Try to deduce arith.h from arithmetic properties. */
26
27#include <stdio.h>
28
29 static int dalign;
30 typedef struct
31Akind {
32	char *name;
33	int   kind;
34	} Akind;
35
36 static Akind
37IEEE_8087	= { "IEEE_8087", 1 },
38IEEE_MC68k	= { "IEEE_MC68k", 2 },
39IBM		= { "IBM", 3 },
40VAX		= { "VAX", 4 },
41CRAY		= { "CRAY", 5};
42
43 static Akind *
44Lcheck()
45{
46	union {
47		double d;
48		long L[2];
49		} u;
50	struct {
51		double d;
52		long L;
53		} x[2];
54
55	if (sizeof(x) > 2*(sizeof(double) + sizeof(long)))
56		dalign = 1;
57	u.L[0] = u.L[1] = 0;
58	u.d = 1e13;
59	if (u.L[0] == 1117925532 && u.L[1] == -448790528)
60		return &IEEE_MC68k;
61	if (u.L[1] == 1117925532 && u.L[0] == -448790528)
62		return &IEEE_8087;
63	if (u.L[0] == -2065213935 && u.L[1] == 10752)
64		return &VAX;
65	if (u.L[0] == 1267827943 && u.L[1] == 704643072)
66		return &IBM;
67	return 0;
68	}
69
70 static Akind *
71icheck()
72{
73	union {
74		double d;
75		int L[2];
76		} u;
77	struct {
78		double d;
79		int L;
80		} x[2];
81
82	if (sizeof(x) > 2*(sizeof(double) + sizeof(int)))
83		dalign = 1;
84	u.L[0] = u.L[1] = 0;
85	u.d = 1e13;
86	if (u.L[0] == 1117925532 && u.L[1] == -448790528)
87		return &IEEE_MC68k;
88	if (u.L[1] == 1117925532 && u.L[0] == -448790528)
89		return &IEEE_8087;
90	if (u.L[0] == -2065213935 && u.L[1] == 10752)
91		return &VAX;
92	if (u.L[0] == 1267827943 && u.L[1] == 704643072)
93		return &IBM;
94	return 0;
95	}
96
97char *emptyfmt = "";	/* avoid possible warning message with printf("") */
98
99 static Akind *
100ccheck()
101{
102	union {
103		double d;
104		long L;
105		} u;
106	long Cray1;
107
108	/* Cray1 = 4617762693716115456 -- without overflow on non-Crays */
109	Cray1 = printf(emptyfmt) < 0 ? 0 : 4617762;
110	if (printf(emptyfmt, Cray1) >= 0)
111		Cray1 = 1000000*Cray1 + 693716;
112	if (printf(emptyfmt, Cray1) >= 0)
113		Cray1 = 1000000*Cray1 + 115456;
114	u.d = 1e13;
115	if (u.L == Cray1)
116		return &CRAY;
117	return 0;
118	}
119
120 static int
121fzcheck()
122{
123	double a, b;
124	int i;
125
126	a = 1.;
127	b = .1;
128	for(i = 155;; b *= b, i >>= 1) {
129		if (i & 1) {
130			a *= b;
131			if (i == 1)
132				break;
133			}
134		}
135	b = a * a;
136	return b == 0.;
137	}
138
139 int
140main()
141{
142	Akind *a = 0;
143	int Ldef = 0;
144	FILE *f;
145
146#ifdef WRITE_ARITH_H	/* for Symantec's buggy "make" */
147	f = fopen("arith.h", "w");
148	if (!f) {
149		printf("Cannot open arith.h\n");
150		return 1;
151		}
152#else
153	f = stdout;
154#endif
155
156	if (sizeof(double) == 2*sizeof(long))
157		a = Lcheck();
158	else if (sizeof(double) == 2*sizeof(int)) {
159		Ldef = 1;
160		a = icheck();
161		}
162	else if (sizeof(double) == sizeof(long))
163		a = ccheck();
164	if (a) {
165		fprintf(f, "#define %s\n#define Arith_Kind_ASL %d\n",
166			a->name, a->kind);
167		if (Ldef)
168			fprintf(f, "#define Long int\n#define Intcast (int)(long)\n");
169		if (dalign)
170			fprintf(f, "#define Double_Align\n");
171		if (sizeof(char*) == 8)
172			fprintf(f, "#define X64_bit_pointers\n");
173#ifndef NO_LONG_LONG
174		if (sizeof(long long) < 8)
175#endif
176			fprintf(f, "#define NO_LONG_LONG\n");
177		if (a->kind <= 2 && fzcheck())
178			fprintf(f, "#define Sudden_Underflow\n");
179		return 0;
180		}
181	fprintf(f, "/* Unknown arithmetic */\n");
182	return 1;
183	}
184