Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 7/13/2023
Public

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?lamc5

Called from ?lamc2. Attempts to compute the largest machine floating-point number, without overflow.

Syntax

call slamc5( beta, p, emin, ieee, emax, rmax)

call dlamc5( beta, p, emin, ieee, emax, rmax)

Include Files

  • mkl.fi

Description

The routine ?lamc5 attempts to compute rmax, the largest machine floating-point number, without overflow. It assumes that emax + abs(emin) sum approximately to a power of 2. It will fail on machines where this assumption does not hold, for example, the Cyber 205 (emin = -28625, emax = 28718). It will also fail if the value supplied for emin is too large (that is, too close to zero), probably with overflow.

Input Parameters

beta

INTEGER. The base of floating-point arithmetic.

p

INTEGER. The number of base beta digits in the mantissa of a floating-point value.

emin

INTEGER. The minimum exponent before (gradual) underflow.

ieee

LOGICAL. A logical flag specifying whether or not the arithmetic system is thought to comply with the IEEE standard.

Output Parameters

emax

INTEGER. The largest exponent before overflow.

rmax

REAL for slamc5

DOUBLE PRECISION for dlamc5

The largest machine floating-point number.