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LAPACK
3.5.0
LAPACK: Linear Algebra PACKage
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Go to the source code of this file.
Functions/Subroutines | |
DOUBLE PRECISION function | dlamch (CMACH) |
DLAMCH | |
DOUBLE PRECISION function | dlamc3 (A, B) |
DLAMC3 |
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.
[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.
DOUBLE PRECISION function dlamch | ( | character | CMACH | ) |
DLAMCH
DLAMCH determines double precision machine 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) |
Definition at line 64 of file dlamch.f.