The <float.h> header file has the following contents:
#ifndef __FLOAT_LOADED
#define __FLOAT_LOADED 1
/*
* <float.h> - Characteristics of floating types
*
* Copyright (c) 1995 by Digital Equipment Corporation. All rights reserved.
*
* DEC C for OpenVMS VAX and OpenVMS Alpha
* DEC C++ for OpenVMS VAX and OpenVMS Alpha
*/
#if defined(__DECC) || defined(__DECCXX)
#pragma __nostandard /* This file uses non-ANSI-Standard features */
#else
#pragma nostandard
#endif
#ifdef __cplusplus
extern "C" {
#endif
#ifndef __G_FLOAT
# if defined(__DECC) || defined(__DECCXX)
# error "__G_FLOAT must be defined"
# else
# ifdef CC$gfloat
# define __G_FLOAT CC$gfloat
# else
# error "Neither __G_FLOAT nor CC$gfloat defined"
# endif
# endif
#endif
#ifndef __IEEE_FLOAT
# define __IEEE_FLOAT 0
#endif
#ifndef __X_FLOAT
# define __X_FLOAT 0
#endif
#ifndef __D_FLOAT
# define __D_FLOAT ((!__G_FLOAT) && (!__IEEE_FLOAT))
#endif
/* Rounding mode for floating point addition: */
#ifdef __BIASED_FLT_ROUNDS
# define FLT_ROUNDS (__BIASED_FLT_ROUNDS - 1) /* use compiler-generated
value, if present */
#else
# define FLT_ROUNDS 1
#endif
/* Radix of exponent representation: */
#define FLT_RADIX 2
/* Number of FLT_RADIX digits in the mantissa including the hidden bit: */
#define __F_FLT_MANT_DIG 24
#define __G_DBL_MANT_DIG 53
#define __S_FLT_MANT_DIG 24
#define __T_FLT_MANT_DIG 53
#define __X_FLT_MANT_DIG 113
#define FLT_MANT_DIG 24
#if __G_FLOAT || __IEEE_FLOAT
# define DBL_MANT_DIG 53
#else
# define DBL_MANT_DIG 56
#endif
#if __X_FLOAT
# define LDBL_MANT_DIG 113
#else
# define LDBL_MANT_DIG DBL_MANT_DIG
#endif
/* Number of decimal digits of precision: */
#define __F_FLT_DIG 6
#define __G_FLT_DIG 15
#define __S_FLT_DIG 6
#define __T_FLT_DIG 15
#define __X_FLT_DIG 33
#define FLT_DIG 6
#if __G_FLOAT || __IEEE_FLOAT
# define DBL_DIG 15
#else
# define DBL_DIG 16
#endif
#if __X_FLOAT
# define LDBL_DIG 33
#else
# define LDBL_DIG DBL_DIG
#endif
/* Minimum negative integer such that FLT_RADIX raised to that power minus 1
is a normalized floating-point number: */
#define __F_FLT_MIN_EXP (-127)
#define __G_FLT_MIN_EXP (-1023)
#define __S_FLT_MIN_EXP (-125)
#define __T_FLT_MIN_EXP (-1021)
#define __X_FLT_MIN_EXP (-16381)
#if __IEEE_FLOAT
# define FLT_MIN_EXP (-125)
#else
# define FLT_MIN_EXP (-127)
#endif
#if __IEEE_FLOAT
# define DBL_MIN_EXP (-1021)
#elif __G_FLOAT
# define DBL_MIN_EXP (-1023)
#else
# define DBL_MIN_EXP (-127)
#endif
#if __X_FLOAT
# define LDBL_MIN_EXP (-16381)
#else
# define LDBL_MIN_EXP DBL_MIN_EXP
#endif
/* Minimum negative integer such that 10 raised to that power
is in the range of normalized floating-point numbers: */
#define __F_FLT_MIN_10_EXP (-38)
#define __G_FLT_MIN_10_EXP (-308)
#define __S_FLT_MIN_10_EXP (-37)
#define __T_FLT_MIN_10_EXP (-307)
#define __X_FLT_MIN_10_EXP (-4931)
#ifdef __IEEE_FLOAT
# define FLT_MIN_10_EXP (-37)
#else
# define FLT_MIN_10_EXP (-38)
#endif
#if __IEEE_FLOAT
# define DBL_MIN_10_EXP (-307)
#elif __G_FLOAT
# define DBL_MIN_10_EXP (-308)
#else
# define DBL_MIN_10_EXP (-38)
#endif
#if __X_FLOAT
# define LDBL_MIN_10_EXP (-4931)
#else
# define LDBL_MIN_10_EXP DBL_MIN_10_EXP
#endif
/* Maximum integer such that FLT_RADIX raised to that power minus 1
is a representable finite floating point number: */
#define __F_FLT_MAX_EXP 127
#define __G_FLT_MAX_EXP 1023
#define __S_FLT_MAX_EXP 128
#define __T_FLT_MAX_EXP 1024
#define __X_FLT_MAX_EXP 16384
#if __IEEE_FLOAT
# define FLT_MAX_EXP 128
#else
# define FLT_MAX_EXP 127
#endif
#if __IEEE_FLOAT
# define DBL_MAX_EXP 1024
#elif __G_FLOAT
# define DBL_MAX_EXP 1023
#else
# define DBL_MAX_EXP 127
#endif
#if __X_FLOAT
# define LDBL_MAX_EXP 16384
#else
# define LDBL_MAX_EXP DBL_MAX_EXP
#endif
/* Maximum integer such that 10 raised to that power
is in the range of representable finite floating-point numbers: */
#define __F_FLT_MAX_10_EXP 38
#define __G_FLT_MAX_10_EXP 307
#define __S_FLT_MAX_10_EXP 38
#define __T_FLT_MAX_10_EXP 308
#define __X_FLT_MAX_10_EXP 4932
#define FLT_MAX_10_EXP 38
#if __IEEE_FLOAT
# define DBL_MAX_10_EXP 308
#elif __G_FLOAT
# define DBL_MAX_10_EXP 307
#else
# define DBL_MAX_10_EXP 38
#endif
#if __X_FLOAT
# define LDBL_MAX_10_EXP 4932
#else
# define LDBL_MAX_10_EXP DBL_MAX_10_EXP
#endif
/* Maximum representable finite floating-point number: */
#define __F_FLT_MAX 1.7014117e+38f
#define __G_FLT_MAX 8.98846567431157854e+307
#ifdef __ALPHA
#define __S_FLT_MAX 3.40282347e+38f
#define __T_FLT_MAX 1.79769313486231570e+308
#define __X_FLT_MAX 1.189731495357231765085759326628007016196477e4932l
#endif
#if __IEEE_FLOAT
# define FLT_MAX 3.40282347e+38f
#else
# define FLT_MAX 1.7014117e+38f
#endif
#if __IEEE_FLOAT
# define DBL_MAX 1.79769313486231570e+308
#elif __G_FLOAT
# define DBL_MAX 8.98846567431157854e+307
#else
# ifndef __ALPHA
# define DBL_MAX 1.70141183460469229e+38
# else
# define DBL_MAX 1.70141183460469213e+38
# endif
#endif
#if __X_FLOAT
# define LDBL_MAX 1.189731495357231765085759326628007016196477e4932l
#else
# define LDBL_MAX DBL_MAX
#endif
/* The difference between 1.0 and the least value greater than 1.0
that is representable in the given floating-point type
(i.e. 1.0 + epsilon != 1.0): */
#define __F_FLT_EPSILON ((float)(1.0 / (1 << 23)))
#define __G_FLT_EPSILON (1.0 / (1 << 30) / (1 << 22))
#ifdef __ALPHA
#define __S_FLT_EPSILON 1.19209290e-07f
#define __T_FLT_EPSILON 2.2204460492503131e-16
#define __X_FLT_EPSILON 1.9259299443872358530559779425849273185381e-34l
#endif
#if __IEEE_FLOAT
# define FLT_EPSILON 1.19209290e-07f
#else
# define FLT_EPSILON ((float)(1.0 / (1 << 23)))
#endif
#if __IEEE_FLOAT
# define DBL_EPSILON 2.2204460492503131e-16
#elif __G_FLOAT || (__D_FLOAT && defined(__ALPHA))
# define DBL_EPSILON (1.0 / (1 << 20) / (1 << 16) / (1 << 16))
#else
# define DBL_EPSILON (1.0 / (1 << 23) / (1 << 16) / (1 << 16))
#endif
#if __X_FLOAT
# define LDBL_EPSILON 1.9259299443872358530559779425849273185381e-34l
#else
# define LDBL_EPSILON DBL_EPSILON
#endif
/* Minimum normalized positive floating-point number: */
#define __F_FLT_MIN ((float) 2.93873587705571877e-39)
#define __G_FLT_MIN 5.56268464626800346e-309
#ifdef __ALPHA
#define __S_FLT_MIN 1.17549435e-38f
#define __T_FLT_MIN 2.2250738585072014e-308
#define __X_FLT_MIN
((long double) 3.3621031431120935062626778173217526025981e-4932l)
#endif
#if __IEEE_FLOAT
# define FLT_MIN 1.17549435e-38f
#else
# define FLT_MIN ((float)2.93873587705571877e-39)
#endif
#if __IEEE_FLOAT
# define DBL_MIN 2.2250738585072014e-308
#elif __G_FLOAT
# define DBL_MIN 5.56268464626800346e-309
#else
# define DBL_MIN 2.93873587705571877e-39
#endif
#if __X_FLOAT
# define LDBL_MIN 3.3621031431120935062626778173217526025981e-4932l
#else
# define LDBL_MIN DBL_MIN
#endif
#ifdef __cplusplus
}
#endif
#if defined(__DECC) || defined(__DECCXX)
#pragma __standard /* This file uses non-ANSI-Standard features */
#else
#pragma standard
#endif
#endif /* __FLOAT_LOADED */