NAME

slamch - determine single precision machine parameters

SYNOPSIS

REAL FUNCTION
SLAMCH( CMACH )

CHARACTER CMACH

PURPOSE

SLAMCH determines single precision machine parameters. 
 

ARGUMENTS

CMACH   (input) 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)

SunSoft, Inc.  —  Last change: 27 Jun 1995