in cddefines.h the following two are set

#define SMALLFLOAT 1e-35f
#define SMALLDOUBLE 1e-300

to prepare for 64 bit platforms, do not cast pointers to the 32-bit types 
	int, long, ULONG, or DWORD,
	use UINT_PTR or INT_PRT abstract types instead.

in ANSI c limits for the current processor are stored in 
#include <float.h>

for visual c++ on intel nt values are

#define DBL_DIG         15                      /* # of decimal digits of precision */
#define DBL_EPSILON     2.2204460492503131e-016 /* smallest such that 1.0+DBL_EPSILON != 1.0 */
#define DBL_MANT_DIG    53                      /* # of bits in mantissa */
#define DBL_MAX         1.7976931348623158e+308 /* max value */
#define DBL_MAX_10_EXP  308                     /* max decimal exponent */
#define DBL_MAX_EXP     1024                    /* max binary exponent */
#define DBL_MIN         2.2250738585072014e-308 /* min positive value */
#define DBL_MIN_10_EXP  (-307)                  /* min decimal exponent */
#define DBL_MIN_EXP     (-1021)                 /* min binary exponent */
#define _DBL_RADIX      2                       /* exponent radix */
#define _DBL_ROUNDS     1                       /* addition rounding: near */

#define FLT_DIG         6                       /* # of decimal digits of precision */
#define FLT_EPSILON     1.192092896e-07F        /* smallest such that 1.0+FLT_EPSILON != 1.0 */
#define FLT_GUARD       0
#define FLT_MANT_DIG    24                      /* # of bits in mantissa */
#define FLT_MAX         3.402823466e+38F        /* max value */
#define FLT_MAX_10_EXP  38                      /* max decimal exponent */
#define FLT_MAX_EXP     128                     /* max binary exponent */
#define FLT_MIN         1.175494351e-38F        /* min positive value */
#define FLT_MIN_10_EXP  (-37)                   /* min decimal exponent */
#define FLT_MIN_EXP     (-125)                  /* min binary exponent */
#define FLT_NORMALIZE   0
#define FLT_RADIX       2                       /* exponent radix */
#define FLT_ROUNDS      1                       /* addition rounding: near */

in ANSI C interger limits are in
#include <limits.h>
#define MB_LEN_MAX    2             /* max. # bytes in multibyte char */
#define SHRT_MIN    (-32768)        /* minimum (signed) short value */
#define SHRT_MAX      32767         /* maximum (signed) short value */
#define USHRT_MAX     0xffff        /* maximum unsigned short value */
#define INT_MIN     (-2147483647 - 1) /* minimum (signed) int value */
#define INT_MAX       2147483647    /* maximum (signed) int value */
#define UINT_MAX      0xffffffff    /* maximum unsigned int value */
#define LONG_MIN    (-2147483647L - 1) /* minimum (signed) long value */
#define LONG_MAX      2147483647L   /* maximum (signed) long value */
#define ULONG_MAX     0xffffffffUL  /* maximum unsigned long value */