float.h revision 1.25 
1/*	$NetBSD: float.h,v 1.25 2025/10/04 21:12:36 nat Exp $	*/
2
3#ifndef _M68K_FLOAT_H_
4#define _M68K_FLOAT_H_
5
6#include <sys/featuretest.h>
7
8/*
9 * LDBL_MIN is half the x86 LDBL_MIN, even though both are 12-byte
10 * floats with the same base properties and both allegedly
11 * IEEE-compliant, because both these representations materialize the
12 * top (integer-part) bit of the mantissa. But on m68k if the exponent
13 * is 0 and the integer bit is set, it's a regular number, whereas on
14 * x86 it's called a pseudo-denormal and apparently treated as a
15 * denormal, so it doesn't count as a valid value for LDBL_MIN.
16 *
17 * x86 citation: Intel 64 and IA-32 Architectures Software Developer's
18 * Manual, vol. 1 (Order Number: 253665-077US, April 2022), Sec. 8.2.2
19 * `Unsupported Double Extended-Precision Floating-Point Encodings
20 * and Pseudo-Denormals', p. 8-14.
21 *
22 * m86k citation: MC68881/MC68882 Floating-Point Coprocessor User's
23 * Manual, Second Edition (Prentice-Hall, 1989, apparently issued by
24 * Freescale), Section 3.2 `Binary Real Data formats', pg. 3-3 bottom
25 * in particular and pp. 3-2 to 3-5 in general.
26 *
27 * If anyone needs to update this comment please make sure the copy in
28 * x86/include/float.h also gets updated.
29 */
30
31#if defined(__LDBL_MANT_DIG__) && \
32			!(defined(__m68k__) && !defined(__HAVE_68881__))
33#define LDBL_MANT_DIG	__LDBL_MANT_DIG__
34#define LDBL_EPSILON	__LDBL_EPSILON__
35#define LDBL_DIG	__LDBL_DIG__
36#define LDBL_MIN_EXP	__LDBL_MIN_EXP__
37#define LDBL_MIN	__LDBL_MIN__
38#define LDBL_MIN_10_EXP	__LDBL_MIN_10_EXP__
39#define LDBL_MAX_EXP	__LDBL_MAX_EXP__
40#define LDBL_MAX	__LDBL_MAX__
41#define LDBL_MAX_10_EXP	__LDBL_MAX_10_EXP__
42#elif !defined(__mc68010__) && !defined(__mcoldfire__)
43#define LDBL_MANT_DIG	64
44#define LDBL_EPSILON	1.0842021724855044340E-19L
45#define LDBL_DIG	18
46#define LDBL_MIN_EXP	(-16381)
47#define LDBL_MIN	1.6810515715560467531E-4932L
48#define LDBL_MIN_10_EXP	(-4931)
49#define LDBL_MAX_EXP	16384
50#define LDBL_MAX	1.1897314953572317650E+4932L
51#define LDBL_MAX_10_EXP	4932
52#endif
53
54#include <sys/float_ieee754.h>
55
56#if !defined(__mc68010__) && !defined(__mcoldfire__)
57#if !defined(_ANSI_SOURCE) && !defined(_POSIX_C_SOURCE) && \
58    !defined(_XOPEN_SOURCE) || \
59    ((__STDC_VERSION__ - 0) >= 199901L) || \
60    ((_POSIX_C_SOURCE - 0) >= 200112L) || \
61    ((_XOPEN_SOURCE  - 0) >= 600) || \
62    defined(_ISOC99_SOURCE) || defined(_NETBSD_SOURCE)
63#define	DECIMAL_DIG	21
64#endif /* !defined(_ANSI_SOURCE) && ... */
65#endif /* !__mc68010__ && !__mcoldfire__ */
66
67#endif	/* !_M68K_FLOAT_H_ */
68