From 827843bbbdb5a27019d7d679f371a3a69053c762 Mon Sep 17 00:00:00 2001 From: Gael Guennebaud Date: Wed, 12 Jun 2013 10:12:50 +0200 Subject: Complete the lapack interface to make it complete enough for suitesparse QR. --- lapack/slamch.f | 192 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 lapack/slamch.f (limited to 'lapack/slamch.f') diff --git a/lapack/slamch.f b/lapack/slamch.f new file mode 100644 index 000000000..4bffad0eb --- /dev/null +++ b/lapack/slamch.f @@ -0,0 +1,192 @@ +*> \brief \b SLAMCH +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +* Definition: +* =========== +* +* REAL FUNCTION SLAMCH( CMACH ) +* +* .. Scalar Arguments .. +* CHARACTER CMACH +* .. +* +* +*> \par Purpose: +* ============= +*> +*> \verbatim +*> +*> SLAMCH determines single precision machine parameters. +*> \endverbatim +* +* Arguments: +* ========== +* +*> \param[in] CMACH +*> \verbatim +*> 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) +*> \endverbatim +* +* Authors: +* ======== +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup auxOTHERauxiliary +* +* ===================================================================== + REAL FUNCTION SLAMCH( CMACH ) +* +* -- LAPACK auxiliary routine (version 3.4.0) -- +* -- LAPACK is a software package provided by Univ. of Tennessee, -- +* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- +* November 2011 +* +* .. Scalar Arguments .. + CHARACTER CMACH +* .. +* +* ===================================================================== +* +* .. Parameters .. + REAL ONE, ZERO + PARAMETER ( ONE = 1.0E+0, ZERO = 0.0E+0 ) +* .. +* .. Local Scalars .. + REAL RND, EPS, SFMIN, SMALL, RMACH +* .. +* .. External Functions .. + LOGICAL LSAME + EXTERNAL LSAME +* .. +* .. Intrinsic Functions .. + INTRINSIC DIGITS, EPSILON, HUGE, MAXEXPONENT, + $ MINEXPONENT, RADIX, TINY +* .. +* .. Executable Statements .. +* +* +* Assume rounding, not chopping. Always. +* + RND = ONE +* + IF( ONE.EQ.RND ) THEN + EPS = EPSILON(ZERO) * 0.5 + ELSE + EPS = EPSILON(ZERO) + END IF +* + IF( LSAME( CMACH, 'E' ) ) THEN + RMACH = EPS + ELSE IF( LSAME( CMACH, 'S' ) ) THEN + SFMIN = TINY(ZERO) + SMALL = ONE / HUGE(ZERO) + IF( SMALL.GE.SFMIN ) THEN +* +* Use SMALL plus a bit, to avoid the possibility of rounding +* causing overflow when computing 1/sfmin. +* + SFMIN = SMALL*( ONE+EPS ) + END IF + RMACH = SFMIN + ELSE IF( LSAME( CMACH, 'B' ) ) THEN + RMACH = RADIX(ZERO) + ELSE IF( LSAME( CMACH, 'P' ) ) THEN + RMACH = EPS * RADIX(ZERO) + ELSE IF( LSAME( CMACH, 'N' ) ) THEN + RMACH = DIGITS(ZERO) + ELSE IF( LSAME( CMACH, 'R' ) ) THEN + RMACH = RND + ELSE IF( LSAME( CMACH, 'M' ) ) THEN + RMACH = MINEXPONENT(ZERO) + ELSE IF( LSAME( CMACH, 'U' ) ) THEN + RMACH = tiny(zero) + ELSE IF( LSAME( CMACH, 'L' ) ) THEN + RMACH = MAXEXPONENT(ZERO) + ELSE IF( LSAME( CMACH, 'O' ) ) THEN + RMACH = HUGE(ZERO) + ELSE + RMACH = ZERO + END IF +* + SLAMCH = RMACH + RETURN +* +* End of SLAMCH +* + END +************************************************************************ +*> \brief \b SLAMC3 +*> \details +*> \b Purpose: +*> \verbatim +*> 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. +*> \endverbatim +*> \author LAPACK is a software package provided by Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. +*> \date November 2011 +*> \ingroup auxOTHERauxiliary +*> +*> \param[in] A +*> \verbatim +*> \endverbatim +*> +*> \param[in] B +*> \verbatim +*> The values A and B. +*> \endverbatim +*> +* + REAL FUNCTION SLAMC3( A, B ) +* +* -- LAPACK auxiliary routine (version 3.4.0) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2010 +* +* .. Scalar Arguments .. + REAL A, B +* .. +* ===================================================================== +* +* .. Executable Statements .. +* + SLAMC3 = A + B +* + RETURN +* +* End of SLAMC3 +* + END +* +************************************************************************ -- cgit v1.2.3