| 1 | /* $NetBSD: float.h,v 1.8 2024/06/15 11:44:09 rillig Exp $ */ |
| 2 | |
| 3 | #ifndef _X86_FLOAT_H_ |
| 4 | #define _X86_FLOAT_H_ |
| 5 | |
| 6 | #include <sys/featuretest.h> |
| 7 | |
| 8 | /* |
| 9 | * LDBL_MIN is twice the m68k 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 | * m68k/include/float.h also gets updated. |
| 29 | */ |
| 30 | |
| 31 | #define LDBL_MANT_DIG 64 |
| 32 | #define LDBL_EPSILON 1.0842021724855044340E-19L |
| 33 | #define LDBL_DIG 18 |
| 34 | #define LDBL_MIN_EXP (-16381) |
| 35 | #define LDBL_MIN 3.3621031431120935063E-4932L |
| 36 | #define LDBL_MIN_10_EXP (-4931) |
| 37 | #define LDBL_MAX_EXP 16384 |
| 38 | #define LDBL_MAX 1.1897314953572317650E+4932L |
| 39 | #define LDBL_MAX_10_EXP 4932 |
| 40 | |
| 41 | #include <sys/float_ieee754.h> |
| 42 | |
| 43 | #if !defined(_ANSI_SOURCE) && !defined(_POSIX_C_SOURCE) && \ |
| 44 | !defined(_XOPEN_SOURCE) || \ |
| 45 | ((__STDC_VERSION__ - 0) >= 199901L) || \ |
| 46 | ((_POSIX_C_SOURCE - 0) >= 200112L) || \ |
| 47 | ((_XOPEN_SOURCE - 0) >= 600) || \ |
| 48 | defined(_ISOC99_SOURCE) || defined(_NETBSD_SOURCE) |
| 49 | #define DECIMAL_DIG 21 |
| 50 | #endif /* !defined(_ANSI_SOURCE) && ... */ |
| 51 | |
| 52 | #endif /* _X86_FLOAT_H_ */ |