LAMCH - 5.2 English - 68552

AOCL API Guide (68552)

Document ID
68552
Release Date
2025-12-29
Version
5.2 English
template<typename T>
T lamch(char *cmach)#

LAMCH determines single precision machine parameters.

Purpose:

   LAMCH determines single precision machine parameters.
Parameters:

CMACH[in]

CMACH is CHARACTER*1

Specifies the value to be returned by SLAMCH:

= ‘E’ or ‘e’, SLAMCH := eps

= ‘S’ or ‘s , SLAMCH := sfmin

= ‘B’ or ‘b’, SLAMCH := base

= ‘P’ or ‘p’, SLAMCH := eps*base

= ‘N’ or ‘n’, SLAMCH := t

= ‘R’ or ‘r’, SLAMCH := rnd

= ‘M’ or ‘m’, SLAMCH := emin

= ‘U’ or ‘u’, SLAMCH := rmin

= ‘L’ or ‘l’, SLAMCH := emax

= ‘O’ or ‘o’, SLAMCH := rmax

where

eps = relative machine precision

sfmin = safe minimum, such that 1/sfmin does not overflow

base = base of the machine

prec = eps*base

t = number of (base) digits in the mantissa

rnd = 1.0 when rounding occurs in addition, 0.0 otherwise

emin = minimum exponent before (gradual) underflow

rmin = underflow threshold - base**(emin-1)

emax = largest exponent before overflow

rmax = overflow threshold - (base**emax)*(1-eps)
Returns:

T Template based return value of the function.