LAPACK  3.5.0 LAPACK: Linear Algebra PACKage
dlamch.f File Reference

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## Functions/Subroutines

DOUBLE PRECISION function dlamch (CMACH)
DLAMCH More...

DOUBLE PRECISION function dlamc3 (A, B)
DLAMC3 More...

## Function/Subroutine Documentation

 DOUBLE PRECISION function dlamc3 ( double precision A, double precision B )

DLAMC3

Purpose:

``` DLAMC3  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.```
Date
November 2011
Parameters
 [in] A ` A is a DOUBLE PRECISION` [in] B ``` B is a DOUBLE PRECISION The values A and B.```

Definition at line 172 of file dlamch.f.

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 DOUBLE PRECISION function dlamch ( character CMACH )

DLAMCH

Purpose:
` DLAMCH determines double precision machine parameters.`
Parameters
 [in] CMACH ``` Specifies the value to be returned by DLAMCH: = 'E' or 'e', DLAMCH := eps = 'S' or 's , DLAMCH := sfmin = 'B' or 'b', DLAMCH := base = 'P' or 'p', DLAMCH := eps*base = 'N' or 'n', DLAMCH := t = 'R' or 'r', DLAMCH := rnd = 'M' or 'm', DLAMCH := emin = 'U' or 'u', DLAMCH := rmin = 'L' or 'l', DLAMCH := emax = 'O' or 'o', DLAMCH := 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)```
Date
November 2011

Definition at line 64 of file dlamch.f.

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