Developer Reference for Intel® oneAPI Math Kernel Library for C
?lamch
Determines machine parameters for floating-point arithmetic.
Syntax
floatLAPACKE_slamch ( charcmach );
doubleLAPACKE_dlamch ( charcmach );
Include Files
mkl.h
Description
slamch dlamch
The function ?lamch determines single precision and double precision machine parameters.
Input Parameters
cmach
Specifies the value to be returned by ?lamch :
= ‘ E ‘ or ‘ e ‘, val = eps = ‘ S ‘ or ‘ s ‘, val = sfmin = ‘ B ‘ or ‘ b ‘, val = base = ‘ P ‘ or ‘ p ‘, val = eps * base = ‘ n ‘ or ‘ n ‘, val = t = ‘ R ‘ or ‘ r ‘, val = rnd = ‘ M ‘ or ‘ m ‘, val = emin = ‘ U ‘ or ‘ u ‘, val = rmin = ‘L’ or ‘ l ‘, val = emax = ‘ O ‘ or ‘ o ‘, val = 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 ).
Output Parameters
- val
-
REAL for slamch DOUBLE PRECISION for dlamch Value returned by the function.