view ext/cblas/src/dlamch.c @ 209:ccd2019190bf msvc

Some MSVC fixes, including (temporarily, probably) renaming the FFT source file to avoid getting it mixed up with the Vamp SDK one in our object dir
author Chris Cannam
date Thu, 01 Feb 2018 16:34:08 +0000
parents 45330e0d2819
children
line wrap: on
line source
/* dlamch.f -- translated by f2c (version 20061008).
   You must link the resulting object file with libf2c:
	on Microsoft Windows system, link with libf2c.lib;
	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
	or, if you install libf2c.a in a standard place, with -lf2c -lm
	-- in that order, at the end of the command line, as in
		cc *.o -lf2c -lm
	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

		http://www.netlib.org/f2c/libf2c.zip
*/

#include "f2c.h"
#include "blaswrap.h"

/* Table of constant values */

static integer c__1 = 1;
static doublereal c_b32 = 0.;

doublereal dlamch_(char *cmach)
{
    /* Initialized data */

    static logical first = TRUE_;

    /* System generated locals */
    integer i__1;
    doublereal ret_val;

    /* Builtin functions */
    double pow_di(doublereal *, integer *);

    /* Local variables */
    static doublereal t;
    integer it;
    static doublereal rnd, eps, base;
    integer beta;
    static doublereal emin, prec, emax;
    integer imin, imax;
    logical lrnd;
    static doublereal rmin, rmax;
    doublereal rmach;
    extern logical lsame_(char *, char *);
    doublereal small;
    static doublereal sfmin;
    extern /* Subroutine */ int dlamc2_(integer *, integer *, logical *, 
	    doublereal *, integer *, doublereal *, integer *, doublereal *);


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DLAMCH determines double precision machine parameters. */

/*  Arguments */
/*  ========= */

/*  CMACH   (input) CHARACTER*1 */
/*          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) */

/* ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Save statement .. */
/*     .. */
/*     .. Data statements .. */
/*     .. */
/*     .. Executable Statements .. */

    if (first) {
	dlamc2_(&beta, &it, &lrnd, &eps, &imin, &rmin, &imax, &rmax);
	base = (doublereal) beta;
	t = (doublereal) it;
	if (lrnd) {
	    rnd = 1.;
	    i__1 = 1 - it;
	    eps = pow_di(&base, &i__1) / 2;
	} else {
	    rnd = 0.;
	    i__1 = 1 - it;
	    eps = pow_di(&base, &i__1);
	}
	prec = eps * base;
	emin = (doublereal) imin;
	emax = (doublereal) imax;
	sfmin = rmin;
	small = 1. / rmax;
	if (small >= sfmin) {

/*           Use SMALL plus a bit, to avoid the possibility of rounding */
/*           causing overflow when computing  1/sfmin. */

	    sfmin = small * (eps + 1.);
	}
    }

    if (lsame_(cmach, "E")) {
	rmach = eps;
    } else if (lsame_(cmach, "S")) {
	rmach = sfmin;
    } else if (lsame_(cmach, "B")) {
	rmach = base;
    } else if (lsame_(cmach, "P")) {
	rmach = prec;
    } else if (lsame_(cmach, "N")) {
	rmach = t;
    } else if (lsame_(cmach, "R")) {
	rmach = rnd;
    } else if (lsame_(cmach, "M")) {
	rmach = emin;
    } else if (lsame_(cmach, "U")) {
	rmach = rmin;
    } else if (lsame_(cmach, "L")) {
	rmach = emax;
    } else if (lsame_(cmach, "O")) {
	rmach = rmax;
    }

    ret_val = rmach;
    first = FALSE_;
    return ret_val;

/*     End of DLAMCH */

} /* dlamch_ */


/* *********************************************************************** */

/* Subroutine */ int dlamc1_(integer *beta, integer *t, logical *rnd, logical 
	*ieee1)
{
    /* Initialized data */

    static logical first = TRUE_;

    /* System generated locals */
    doublereal d__1, d__2;

    /* Local variables */
    doublereal a, b, c__, f, t1, t2;
    static integer lt;
    doublereal one, qtr;
    static logical lrnd;
    static integer lbeta;
    doublereal savec;
    extern doublereal dlamc3_(doublereal *, doublereal *);
    static logical lieee1;


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DLAMC1 determines the machine parameters given by BETA, T, RND, and */
/*  IEEE1. */

/*  Arguments */
/*  ========= */

/*  BETA    (output) INTEGER */
/*          The base of the machine. */

/*  T       (output) INTEGER */
/*          The number of ( BETA ) digits in the mantissa. */

/*  RND     (output) LOGICAL */
/*          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   (output) LOGICAL */
/*          Specifies whether rounding appears to be done in the IEEE */
/*          'round to nearest' style. */

/*  Further Details */
/*  =============== */

/*  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. */

/* ===================================================================== */

/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Save statement .. */
/*     .. */
/*     .. Data statements .. */
/*     .. */
/*     .. Executable Statements .. */

    if (first) {
	one = 1.;

/*        LBETA,  LIEEE1,  LT and  LRND  are the  local values  of  BETA, */
/*        IEEE1, T and RND. */

/*        Throughout this routine  we use the function  DLAMC3  to ensure */
/*        that relevant values are  stored and not held in registers,  or */
/*        are not affected by optimizers. */

/*        Compute  a = 2.0**m  with the  smallest positive integer m such */
/*        that */

/*           fl( a + 1.0 ) = a. */

	a = 1.;
	c__ = 1.;

/* +       WHILE( C.EQ.ONE )LOOP */
L10:
	if (c__ == one) {
	    a *= 2;
	    c__ = dlamc3_(&a, &one);
	    d__1 = -a;
	    c__ = dlamc3_(&c__, &d__1);
	    goto L10;
	}
/* +       END WHILE */

/*        Now compute  b = 2.0**m  with the smallest positive integer m */
/*        such that */

/*           fl( a + b ) .gt. a. */

	b = 1.;
	c__ = dlamc3_(&a, &b);

/* +       WHILE( C.EQ.A )LOOP */
L20:
	if (c__ == a) {
	    b *= 2;
	    c__ = dlamc3_(&a, &b);
	    goto L20;
	}
/* +       END WHILE */

/*        Now compute the base.  a and c  are neighbouring floating point */
/*        numbers  in the  interval  ( beta**t, beta**( t + 1 ) )  and so */
/*        their difference is beta. Adding 0.25 to c is to ensure that it */
/*        is truncated to beta and not ( beta - 1 ). */

	qtr = one / 4;
	savec = c__;
	d__1 = -a;
	c__ = dlamc3_(&c__, &d__1);
	lbeta = (integer) (c__ + qtr);

/*        Now determine whether rounding or chopping occurs,  by adding a */
/*        bit  less  than  beta/2  and a  bit  more  than  beta/2  to  a. */

	b = (doublereal) lbeta;
	d__1 = b / 2;
	d__2 = -b / 100;
	f = dlamc3_(&d__1, &d__2);
	c__ = dlamc3_(&f, &a);
	if (c__ == a) {
	    lrnd = TRUE_;
	} else {
	    lrnd = FALSE_;
	}
	d__1 = b / 2;
	d__2 = b / 100;
	f = dlamc3_(&d__1, &d__2);
	c__ = dlamc3_(&f, &a);
	if (lrnd && c__ == a) {
	    lrnd = FALSE_;
	}

/*        Try and decide whether rounding is done in the  IEEE  'round to */
/*        nearest' style. B/2 is half a unit in the last place of the two */
/*        numbers A and SAVEC. Furthermore, A is even, i.e. has last  bit */
/*        zero, and SAVEC is odd. Thus adding B/2 to A should not  change */
/*        A, but adding B/2 to SAVEC should change SAVEC. */

	d__1 = b / 2;
	t1 = dlamc3_(&d__1, &a);
	d__1 = b / 2;
	t2 = dlamc3_(&d__1, &savec);
	lieee1 = t1 == a && t2 > savec && lrnd;

/*        Now find  the  mantissa, t.  It should  be the  integer part of */
/*        log to the base beta of a,  however it is safer to determine  t */
/*        by powering.  So we find t as the smallest positive integer for */
/*        which */

/*           fl( beta**t + 1.0 ) = 1.0. */

	lt = 0;
	a = 1.;
	c__ = 1.;

/* +       WHILE( C.EQ.ONE )LOOP */
L30:
	if (c__ == one) {
	    ++lt;
	    a *= lbeta;
	    c__ = dlamc3_(&a, &one);
	    d__1 = -a;
	    c__ = dlamc3_(&c__, &d__1);
	    goto L30;
	}
/* +       END WHILE */

    }

    *beta = lbeta;
    *t = lt;
    *rnd = lrnd;
    *ieee1 = lieee1;
    first = FALSE_;
    return 0;

/*     End of DLAMC1 */

} /* dlamc1_ */


/* *********************************************************************** */

/* Subroutine */ int dlamc2_(integer *beta, integer *t, logical *rnd, 
	doublereal *eps, integer *emin, doublereal *rmin, integer *emax, 
	doublereal *rmax)
{
    /* Initialized data */

    static logical first = TRUE_;
    static logical iwarn = FALSE_;

    /* Format strings */
    static char fmt_9999[] = "(//\002 WARNING. The value EMIN may be incorre"
	    "ct:-\002,\002  EMIN = \002,i8,/\002 If, after inspection, the va"
	    "lue EMIN looks\002,\002 acceptable please comment out \002,/\002"
	    " the IF block as marked within the code of routine\002,\002 DLAM"
	    "C2,\002,/\002 otherwise supply EMIN explicitly.\002,/)";

    /* System generated locals */
    integer i__1;
    doublereal d__1, d__2, d__3, d__4, d__5;

    /* Builtin functions */
    double pow_di(doublereal *, integer *);
    integer s_wsfe(cilist *), do_fio(integer *, char *, ftnlen), e_wsfe(void);

    /* Local variables */
    doublereal a, b, c__;
    integer i__;
    static integer lt;
    doublereal one, two;
    logical ieee;
    doublereal half;
    logical lrnd;
    static doublereal leps;
    doublereal zero;
    static integer lbeta;
    doublereal rbase;
    static integer lemin, lemax;
    integer gnmin;
    doublereal small;
    integer gpmin;
    doublereal third;
    static doublereal lrmin, lrmax;
    doublereal sixth;
    extern /* Subroutine */ int dlamc1_(integer *, integer *, logical *, 
	    logical *);
    extern doublereal dlamc3_(doublereal *, doublereal *);
    logical lieee1;
    extern /* Subroutine */ int dlamc4_(integer *, doublereal *, integer *), 
	    dlamc5_(integer *, integer *, integer *, logical *, integer *, 
	    doublereal *);
    integer ngnmin, ngpmin;

    /* Fortran I/O blocks */
    static cilist io___58 = { 0, 6, 0, fmt_9999, 0 };



/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DLAMC2 determines the machine parameters specified in its argument */
/*  list. */

/*  Arguments */
/*  ========= */

/*  BETA    (output) INTEGER */
/*          The base of the machine. */

/*  T       (output) INTEGER */
/*          The number of ( BETA ) digits in the mantissa. */

/*  RND     (output) LOGICAL */
/*          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     (output) DOUBLE PRECISION */
/*          The smallest positive number such that */

/*             fl( 1.0 - EPS ) .LT. 1.0, */

/*          where fl denotes the computed value. */

/*  EMIN    (output) INTEGER */
/*          The minimum exponent before (gradual) underflow occurs. */

/*  RMIN    (output) DOUBLE PRECISION */
/*          The smallest normalized number for the machine, given by */
/*          BASE**( EMIN - 1 ), where  BASE  is the floating point value */
/*          of BETA. */

/*  EMAX    (output) INTEGER */
/*          The maximum exponent before overflow occurs. */

/*  RMAX    (output) DOUBLE PRECISION */
/*          The largest positive number for the machine, given by */
/*          BASE**EMAX * ( 1 - EPS ), where  BASE  is the floating point */
/*          value of BETA. */

/*  Further Details */
/*  =============== */

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

/* ===================================================================== */

/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Save statement .. */
/*     .. */
/*     .. Data statements .. */
/*     .. */
/*     .. Executable Statements .. */

    if (first) {
	zero = 0.;
	one = 1.;
	two = 2.;

/*        LBETA, LT, LRND, LEPS, LEMIN and LRMIN  are the local values of */
/*        BETA, T, RND, EPS, EMIN and RMIN. */

/*        Throughout this routine  we use the function  DLAMC3  to ensure */
/*        that relevant values are stored  and not held in registers,  or */
/*        are not affected by optimizers. */

/*        DLAMC1 returns the parameters  LBETA, LT, LRND and LIEEE1. */

	dlamc1_(&lbeta, &lt, &lrnd, &lieee1);

/*        Start to find EPS. */

	b = (doublereal) lbeta;
	i__1 = -lt;
	a = pow_di(&b, &i__1);
	leps = a;

/*        Try some tricks to see whether or not this is the correct  EPS. */

	b = two / 3;
	half = one / 2;
	d__1 = -half;
	sixth = dlamc3_(&b, &d__1);
	third = dlamc3_(&sixth, &sixth);
	d__1 = -half;
	b = dlamc3_(&third, &d__1);
	b = dlamc3_(&b, &sixth);
	b = abs(b);
	if (b < leps) {
	    b = leps;
	}

	leps = 1.;

/* +       WHILE( ( LEPS.GT.B ).AND.( B.GT.ZERO ) )LOOP */
L10:
	if (leps > b && b > zero) {
	    leps = b;
	    d__1 = half * leps;
/* Computing 5th power */
	    d__3 = two, d__4 = d__3, d__3 *= d__3;
/* Computing 2nd power */
	    d__5 = leps;
	    d__2 = d__4 * (d__3 * d__3) * (d__5 * d__5);
	    c__ = dlamc3_(&d__1, &d__2);
	    d__1 = -c__;
	    c__ = dlamc3_(&half, &d__1);
	    b = dlamc3_(&half, &c__);
	    d__1 = -b;
	    c__ = dlamc3_(&half, &d__1);
	    b = dlamc3_(&half, &c__);
	    goto L10;
	}
/* +       END WHILE */

	if (a < leps) {
	    leps = a;
	}

/*        Computation of EPS complete. */

/*        Now find  EMIN.  Let A = + or - 1, and + or - (1 + BASE**(-3)). */
/*        Keep dividing  A by BETA until (gradual) underflow occurs. This */
/*        is detected when we cannot recover the previous A. */

	rbase = one / lbeta;
	small = one;
	for (i__ = 1; i__ <= 3; ++i__) {
	    d__1 = small * rbase;
	    small = dlamc3_(&d__1, &zero);
/* L20: */
	}
	a = dlamc3_(&one, &small);
	dlamc4_(&ngpmin, &one, &lbeta);
	d__1 = -one;
	dlamc4_(&ngnmin, &d__1, &lbeta);
	dlamc4_(&gpmin, &a, &lbeta);
	d__1 = -a;
	dlamc4_(&gnmin, &d__1, &lbeta);
	ieee = FALSE_;

	if (ngpmin == ngnmin && gpmin == gnmin) {
	    if (ngpmin == gpmin) {
		lemin = ngpmin;
/*            ( Non twos-complement machines, no gradual underflow; */
/*              e.g.,  VAX ) */
	    } else if (gpmin - ngpmin == 3) {
		lemin = ngpmin - 1 + lt;
		ieee = TRUE_;
/*            ( Non twos-complement machines, with gradual underflow; */
/*              e.g., IEEE standard followers ) */
	    } else {
		lemin = min(ngpmin,gpmin);
/*            ( A guess; no known machine ) */
		iwarn = TRUE_;
	    }

	} else if (ngpmin == gpmin && ngnmin == gnmin) {
	    if ((i__1 = ngpmin - ngnmin, abs(i__1)) == 1) {
		lemin = max(ngpmin,ngnmin);
/*            ( Twos-complement machines, no gradual underflow; */
/*              e.g., CYBER 205 ) */
	    } else {
		lemin = min(ngpmin,ngnmin);
/*            ( A guess; no known machine ) */
		iwarn = TRUE_;
	    }

	} else if ((i__1 = ngpmin - ngnmin, abs(i__1)) == 1 && gpmin == gnmin)
		 {
	    if (gpmin - min(ngpmin,ngnmin) == 3) {
		lemin = max(ngpmin,ngnmin) - 1 + lt;
/*            ( Twos-complement machines with gradual underflow; */
/*              no known machine ) */
	    } else {
		lemin = min(ngpmin,ngnmin);
/*            ( A guess; no known machine ) */
		iwarn = TRUE_;
	    }

	} else {
/* Computing MIN */
	    i__1 = min(ngpmin,ngnmin), i__1 = min(i__1,gpmin);
	    lemin = min(i__1,gnmin);
/*         ( A guess; no known machine ) */
	    iwarn = TRUE_;
	}
	first = FALSE_;
/* ** */
/* Comment out this if block if EMIN is ok */
	if (iwarn) {
	    first = TRUE_;
	    s_wsfe(&io___58);
	    do_fio(&c__1, (char *)&lemin, (ftnlen)sizeof(integer));
	    e_wsfe();
	}
/* ** */

/*        Assume IEEE arithmetic if we found denormalised  numbers above, */
/*        or if arithmetic seems to round in the  IEEE style,  determined */
/*        in routine DLAMC1. A true IEEE machine should have both  things */
/*        true; however, faulty machines may have one or the other. */

	ieee = ieee || lieee1;

/*        Compute  RMIN by successive division by  BETA. We could compute */
/*        RMIN as BASE**( EMIN - 1 ),  but some machines underflow during */
/*        this computation. */

	lrmin = 1.;
	i__1 = 1 - lemin;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    d__1 = lrmin * rbase;
	    lrmin = dlamc3_(&d__1, &zero);
/* L30: */
	}

/*        Finally, call DLAMC5 to compute EMAX and RMAX. */

	dlamc5_(&lbeta, &lt, &lemin, &ieee, &lemax, &lrmax);
    }

    *beta = lbeta;
    *t = lt;
    *rnd = lrnd;
    *eps = leps;
    *emin = lemin;
    *rmin = lrmin;
    *emax = lemax;
    *rmax = lrmax;

    return 0;


/*     End of DLAMC2 */

} /* dlamc2_ */


/* *********************************************************************** */

doublereal dlamc3_(doublereal *a, doublereal *b)
{
    /* System generated locals */
    doublereal ret_val;


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  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. */

/*  Arguments */
/*  ========= */

/*  A       (input) DOUBLE PRECISION */
/*  B       (input) DOUBLE PRECISION */
/*          The values A and B. */

/* ===================================================================== */

/*     .. Executable Statements .. */

    ret_val = *a + *b;

    return ret_val;

/*     End of DLAMC3 */

} /* dlamc3_ */


/* *********************************************************************** */

/* Subroutine */ int dlamc4_(integer *emin, doublereal *start, integer *base)
{
    /* System generated locals */
    integer i__1;
    doublereal d__1;

    /* Local variables */
    doublereal a;
    integer i__;
    doublereal b1, b2, c1, c2, d1, d2, one, zero, rbase;
    extern doublereal dlamc3_(doublereal *, doublereal *);


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DLAMC4 is a service routine for DLAMC2. */

/*  Arguments */
/*  ========= */

/*  EMIN    (output) INTEGER */
/*          The minimum exponent before (gradual) underflow, computed by */
/*          setting A = START and dividing by BASE until the previous A */
/*          can not be recovered. */

/*  START   (input) DOUBLE PRECISION */
/*          The starting point for determining EMIN. */

/*  BASE    (input) INTEGER */
/*          The base of the machine. */

/* ===================================================================== */

/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Executable Statements .. */

    a = *start;
    one = 1.;
    rbase = one / *base;
    zero = 0.;
    *emin = 1;
    d__1 = a * rbase;
    b1 = dlamc3_(&d__1, &zero);
    c1 = a;
    c2 = a;
    d1 = a;
    d2 = a;
/* +    WHILE( ( C1.EQ.A ).AND.( C2.EQ.A ).AND. */
/*    $       ( D1.EQ.A ).AND.( D2.EQ.A )      )LOOP */
L10:
    if (c1 == a && c2 == a && d1 == a && d2 == a) {
	--(*emin);
	a = b1;
	d__1 = a / *base;
	b1 = dlamc3_(&d__1, &zero);
	d__1 = b1 * *base;
	c1 = dlamc3_(&d__1, &zero);
	d1 = zero;
	i__1 = *base;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    d1 += b1;
/* L20: */
	}
	d__1 = a * rbase;
	b2 = dlamc3_(&d__1, &zero);
	d__1 = b2 / rbase;
	c2 = dlamc3_(&d__1, &zero);
	d2 = zero;
	i__1 = *base;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    d2 += b2;
/* L30: */
	}
	goto L10;
    }
/* +    END WHILE */

    return 0;

/*     End of DLAMC4 */

} /* dlamc4_ */


/* *********************************************************************** */

/* Subroutine */ int dlamc5_(integer *beta, integer *p, integer *emin, 
	logical *ieee, integer *emax, doublereal *rmax)
{
    /* System generated locals */
    integer i__1;
    doublereal d__1;

    /* Local variables */
    integer i__;
    doublereal y, z__;
    integer try__, lexp;
    doublereal oldy;
    integer uexp, nbits;
    extern doublereal dlamc3_(doublereal *, doublereal *);
    doublereal recbas;
    integer exbits, expsum;


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DLAMC5 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. */

/*  Arguments */
/*  ========= */

/*  BETA    (input) INTEGER */
/*          The base of floating-point arithmetic. */

/*  P       (input) INTEGER */
/*          The number of base BETA digits in the mantissa of a */
/*          floating-point value. */

/*  EMIN    (input) INTEGER */
/*          The minimum exponent before (gradual) underflow. */

/*  IEEE    (input) LOGICAL */
/*          A logical flag specifying whether or not the arithmetic */
/*          system is thought to comply with the IEEE standard. */

/*  EMAX    (output) INTEGER */
/*          The largest exponent before overflow */

/*  RMAX    (output) DOUBLE PRECISION */
/*          The largest machine floating-point number. */

/* ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     First compute LEXP and UEXP, two powers of 2 that bound */
/*     abs(EMIN). We then assume that EMAX + abs(EMIN) will sum */
/*     approximately to the bound that is closest to abs(EMIN). */
/*     (EMAX is the exponent of the required number RMAX). */

    lexp = 1;
    exbits = 1;
L10:
    try__ = lexp << 1;
    if (try__ <= -(*emin)) {
	lexp = try__;
	++exbits;
	goto L10;
    }
    if (lexp == -(*emin)) {
	uexp = lexp;
    } else {
	uexp = try__;
	++exbits;
    }

/*     Now -LEXP is less than or equal to EMIN, and -UEXP is greater */
/*     than or equal to EMIN. EXBITS is the number of bits needed to */
/*     store the exponent. */

    if (uexp + *emin > -lexp - *emin) {
	expsum = lexp << 1;
    } else {
	expsum = uexp << 1;
    }

/*     EXPSUM is the exponent range, approximately equal to */
/*     EMAX - EMIN + 1 . */

    *emax = expsum + *emin - 1;
    nbits = exbits + 1 + *p;

/*     NBITS is the total number of bits needed to store a */
/*     floating-point number. */

    if (nbits % 2 == 1 && *beta == 2) {

/*        Either there are an odd number of bits used to store a */
/*        floating-point number, which is unlikely, or some bits are */
/*        not used in the representation of numbers, which is possible, */
/*        (e.g. Cray machines) or the mantissa has an implicit bit, */
/*        (e.g. IEEE machines, Dec Vax machines), which is perhaps the */
/*        most likely. We have to assume the last alternative. */
/*        If this is true, then we need to reduce EMAX by one because */
/*        there must be some way of representing zero in an implicit-bit */
/*        system. On machines like Cray, we are reducing EMAX by one */
/*        unnecessarily. */

	--(*emax);
    }

    if (*ieee) {

/*        Assume we are on an IEEE machine which reserves one exponent */
/*        for infinity and NaN. */

	--(*emax);
    }

/*     Now create RMAX, the largest machine number, which should */
/*     be equal to (1.0 - BETA**(-P)) * BETA**EMAX . */

/*     First compute 1.0 - BETA**(-P), being careful that the */
/*     result is less than 1.0 . */

    recbas = 1. / *beta;
    z__ = *beta - 1.;
    y = 0.;
    i__1 = *p;
    for (i__ = 1; i__ <= i__1; ++i__) {
	z__ *= recbas;
	if (y < 1.) {
	    oldy = y;
	}
	y = dlamc3_(&y, &z__);
/* L20: */
    }
    if (y >= 1.) {
	y = oldy;
    }

/*     Now multiply by BETA**EMAX to get RMAX. */

    i__1 = *emax;
    for (i__ = 1; i__ <= i__1; ++i__) {
	d__1 = y * *beta;
	y = dlamc3_(&d__1, &c_b32);
/* L30: */
    }

    *rmax = y;
    return 0;

/*     End of DLAMC5 */

} /* dlamc5_ */