!> SLAMC1 determines the machine parameters given by BETA, T, RND, and
!> IEEE1.
!> 

BETA

!>          The base of the machine.
!> 

T

!>          The number of ( BETA ) digits in the mantissa.
!> 

RND

!>          Specifies whether proper rounding  ( RND = .TRUE. )  or
!>          chopping  ( RND = .FALSE. )  occurs in addition. This may not
!>          be a reliable guide to the way in which the machine performs
!>          its arithmetic.
!> 

IEEE1

!>          Specifies whether rounding appears to be done in the IEEE
!>          'round to nearest' style.
!> 

LAPACK is a software package provided by Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..

!>
!>  The routine is based on the routine  ENVRON  by Malcolm and
!>  incorporates suggestions by Gentleman and Marovich. See
!>
!>     Malcolm M. A. (1972) Algorithms to reveal properties of
!>        floating-point arithmetic. Comms. of the ACM, 15, 949-951.
!>
!>     Gentleman W. M. and Marovich S. B. (1974) More on algorithms
!>        that reveal properties of floating point arithmetic units.
!>        Comms. of the ACM, 17, 276-277.
!> 

!> SLAMC2 determines the machine parameters specified in its argument
!> list.
!> 

LAPACK is a software package provided by Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..

BETA

!>          The base of the machine.
!> 

T

!>          The number of ( BETA ) digits in the mantissa.
!> 

RND

!>          Specifies whether proper rounding  ( RND = .TRUE. )  or
!>          chopping  ( RND = .FALSE. )  occurs in addition. This may not
!>          be a reliable guide to the way in which the machine performs
!>          its arithmetic.
!> 

EPS

!>          The smallest positive number such that
!>             fl( 1.0 - EPS ) .LT. 1.0,
!>          where fl denotes the computed value.
!> 

EMIN

!>          The minimum exponent before (gradual) underflow occurs.
!> 

RMIN

!>          The smallest normalized number for the machine, given by
!>          BASE**( EMIN - 1 ), where  BASE  is the floating point value
!>          of BETA.
!> 

EMAX

!>          The maximum exponent before overflow occurs.
!> 

RMAX

!>          The largest positive number for the machine, given by
!>          BASE**EMAX * ( 1 - EPS ), where  BASE  is the floating point
!>          value of BETA.
!> 

!>
!>  The computation of  EPS  is based on a routine PARANOIA by
!>  W. Kahan of the University of California at Berkeley.
!> 

!> SLAMC3  is intended to force  A  and  B  to be stored prior to doing
!> the addition of  A  and  B ,  for use in situations where optimizers
!> might hold one of these in a register.
!> 

LAPACK is a software package provided by Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..

A

!> 

B

!>          The values A and B.
!> 

!> SLAMC3  is intended to force  A  and  B  to be stored prior to doing
!> the addition of  A  and  B ,  for use in situations where optimizers
!> might hold one of these in a register.
!> 

A
B

!>          The values A and B.
!> 

!> SLAMC4 is a service routine for SLAMC2.
!> 

EMIN

!>          The minimum exponent before (gradual) underflow, computed by
!>          setting A = START and dividing by BASE until the previous A
!>          can not be recovered.
!> 

START

!>          The starting point for determining EMIN.
!> 

BASE

!>          The base of the machine.
!> 

!> SLAMC5 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 (i.e. too close to zero), probably with overflow.
!> 

BETA

!>          The base of floating-point arithmetic.
!> 

P

!>          The number of base BETA digits in the mantissa of a
!>          floating-point value.
!> 

EMIN

!>          The minimum exponent before (gradual) underflow.
!> 

IEEE

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

EMAX

!>          The largest exponent before overflow
!> 

RMAX

!>          The largest machine floating-point number.
!> 

!>
!> SLAMCH determines single precision machine parameters.
!> 

CMACH

!>          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)
!> 

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

!>
!> SLAMCH determines single precision machine parameters.
!> 

CMACH

!>          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)
!> 

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.