starpu-max/min-dgels/base/SRC/dlasr.c

/* dlasr.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"

/* Subroutine */ int dlasr_(char *side, char *pivot, char *direct, integer *m, 
	 integer *n, doublereal *c__, doublereal *s, doublereal *a, integer *
	lda)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2;

    /* Local variables */
    integer i__, j, info;
    doublereal temp;
    extern logical lsame_(char *, char *);
    doublereal ctemp, stemp;
    extern /* Subroutine */ int xerbla_(char *, integer *);


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

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

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

/*  DLASR applies a sequence of plane rotations to a real matrix A, */
/*  from either the left or the right. */

/*  When SIDE = 'L', the transformation takes the form */

/*     A := P*A */

/*  and when SIDE = 'R', the transformation takes the form */

/*     A := A*P**T */

/*  where P is an orthogonal matrix consisting of a sequence of z plane */
/*  rotations, with z = M when SIDE = 'L' and z = N when SIDE = 'R', */
/*  and P**T is the transpose of P. */

/*  When DIRECT = 'F' (Forward sequence), then */

/*     P = P(z-1) * ... * P(2) * P(1) */

/*  and when DIRECT = 'B' (Backward sequence), then */

/*     P = P(1) * P(2) * ... * P(z-1) */

/*  where P(k) is a plane rotation matrix defined by the 2-by-2 rotation */

/*     R(k) = (  c(k)  s(k) ) */
/*          = ( -s(k)  c(k) ). */

/*  When PIVOT = 'V' (Variable pivot), the rotation is performed */
/*  for the plane (k,k+1), i.e., P(k) has the form */

/*     P(k) = (  1                                            ) */
/*            (       ...                                     ) */
/*            (              1                                ) */
/*            (                   c(k)  s(k)                  ) */
/*            (                  -s(k)  c(k)                  ) */
/*            (                                1              ) */
/*            (                                     ...       ) */
/*            (                                            1  ) */

/*  where R(k) appears as a rank-2 modification to the identity matrix in */
/*  rows and columns k and k+1. */

/*  When PIVOT = 'T' (Top pivot), the rotation is performed for the */
/*  plane (1,k+1), so P(k) has the form */

/*     P(k) = (  c(k)                    s(k)                 ) */
/*            (         1                                     ) */
/*            (              ...                              ) */
/*            (                     1                         ) */
/*            ( -s(k)                    c(k)                 ) */
/*            (                                 1             ) */
/*            (                                      ...      ) */
/*            (                                             1 ) */

/*  where R(k) appears in rows and columns 1 and k+1. */

/*  Similarly, when PIVOT = 'B' (Bottom pivot), the rotation is */
/*  performed for the plane (k,z), giving P(k) the form */

/*     P(k) = ( 1                                             ) */
/*            (      ...                                      ) */
/*            (             1                                 ) */
/*            (                  c(k)                    s(k) ) */
/*            (                         1                     ) */
/*            (                              ...              ) */
/*            (                                     1         ) */
/*            (                 -s(k)                    c(k) ) */

/*  where R(k) appears in rows and columns k and z.  The rotations are */
/*  performed without ever forming P(k) explicitly. */

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

/*  SIDE    (input) CHARACTER*1 */
/*          Specifies whether the plane rotation matrix P is applied to */
/*          A on the left or the right. */
/*          = 'L':  Left, compute A := P*A */
/*          = 'R':  Right, compute A:= A*P**T */

/*  PIVOT   (input) CHARACTER*1 */
/*          Specifies the plane for which P(k) is a plane rotation */
/*          matrix. */
/*          = 'V':  Variable pivot, the plane (k,k+1) */
/*          = 'T':  Top pivot, the plane (1,k+1) */
/*          = 'B':  Bottom pivot, the plane (k,z) */

/*  DIRECT  (input) CHARACTER*1 */
/*          Specifies whether P is a forward or backward sequence of */
/*          plane rotations. */
/*          = 'F':  Forward, P = P(z-1)*...*P(2)*P(1) */
/*          = 'B':  Backward, P = P(1)*P(2)*...*P(z-1) */

/*  M       (input) INTEGER */
/*          The number of rows of the matrix A.  If m <= 1, an immediate */
/*          return is effected. */

/*  N       (input) INTEGER */
/*          The number of columns of the matrix A.  If n <= 1, an */
/*          immediate return is effected. */

/*  C       (input) DOUBLE PRECISION array, dimension */
/*                  (M-1) if SIDE = 'L' */
/*                  (N-1) if SIDE = 'R' */
/*          The cosines c(k) of the plane rotations. */

/*  S       (input) DOUBLE PRECISION array, dimension */
/*                  (M-1) if SIDE = 'L' */
/*                  (N-1) if SIDE = 'R' */
/*          The sines s(k) of the plane rotations.  The 2-by-2 plane */
/*          rotation part of the matrix P(k), R(k), has the form */
/*          R(k) = (  c(k)  s(k) ) */
/*                 ( -s(k)  c(k) ). */

/*  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
/*          The M-by-N matrix A.  On exit, A is overwritten by P*A if */
/*          SIDE = 'R' or by A*P**T if SIDE = 'L'. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,M). */

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

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

/*     Test the input parameters */

    /* Parameter adjustments */
    --c__;
    --s;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;

    /* Function Body */
    info = 0;
    if (! (lsame_(side, "L") || lsame_(side, "R"))) {
	info = 1;
    } else if (! (lsame_(pivot, "V") || lsame_(pivot, 
	    "T") || lsame_(pivot, "B"))) {
	info = 2;
    } else if (! (lsame_(direct, "F") || lsame_(direct, 
	    "B"))) {
	info = 3;
    } else if (*m < 0) {
	info = 4;
    } else if (*n < 0) {
	info = 5;
    } else if (*lda < max(1,*m)) {
	info = 9;
    }
    if (info != 0) {
	xerbla_("DLASR ", &info);
	return 0;
    }

/*     Quick return if possible */

    if (*m == 0 || *n == 0) {
	return 0;
    }
    if (lsame_(side, "L")) {

/*        Form  P * A */

	if (lsame_(pivot, "V")) {
	    if (lsame_(direct, "F")) {
		i__1 = *m - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + 1 + i__ * a_dim1];
			    a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * 
				    a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j 
				    + i__ * a_dim1];
/* L10: */
			}
		    }
/* L20: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *m - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + 1 + i__ * a_dim1];
			    a[j + 1 + i__ * a_dim1] = ctemp * temp - stemp * 
				    a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * temp + ctemp * a[j 
				    + i__ * a_dim1];
/* L30: */
			}
		    }
/* L40: */
		}
	    }
	} else if (lsame_(pivot, "T")) {
	    if (lsame_(direct, "F")) {
		i__1 = *m;
		for (j = 2; j <= i__1; ++j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = ctemp * temp - stemp * a[
				    i__ * a_dim1 + 1];
			    a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[
				    i__ * a_dim1 + 1];
/* L50: */
			}
		    }
/* L60: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *m; j >= 2; --j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = ctemp * temp - stemp * a[
				    i__ * a_dim1 + 1];
			    a[i__ * a_dim1 + 1] = stemp * temp + ctemp * a[
				    i__ * a_dim1 + 1];
/* L70: */
			}
		    }
/* L80: */
		}
	    }
	} else if (lsame_(pivot, "B")) {
	    if (lsame_(direct, "F")) {
		i__1 = *m - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *n;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1]
				     + ctemp * temp;
			    a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * 
				    a_dim1] - stemp * temp;
/* L90: */
			}
		    }
/* L100: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *m - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *n;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[j + i__ * a_dim1];
			    a[j + i__ * a_dim1] = stemp * a[*m + i__ * a_dim1]
				     + ctemp * temp;
			    a[*m + i__ * a_dim1] = ctemp * a[*m + i__ * 
				    a_dim1] - stemp * temp;
/* L110: */
			}
		    }
/* L120: */
		}
	    }
	}
    } else if (lsame_(side, "R")) {

/*        Form A * P' */

	if (lsame_(pivot, "V")) {
	    if (lsame_(direct, "F")) {
		i__1 = *n - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + (j + 1) * a_dim1];
			    a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp *
				     a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * temp + ctemp * a[
				    i__ + j * a_dim1];
/* L130: */
			}
		    }
/* L140: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *n - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + (j + 1) * a_dim1];
			    a[i__ + (j + 1) * a_dim1] = ctemp * temp - stemp *
				     a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * temp + ctemp * a[
				    i__ + j * a_dim1];
/* L150: */
			}
		    }
/* L160: */
		}
	    }
	} else if (lsame_(pivot, "T")) {
	    if (lsame_(direct, "F")) {
		i__1 = *n;
		for (j = 2; j <= i__1; ++j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = ctemp * temp - stemp * a[
				    i__ + a_dim1];
			    a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + 
				    a_dim1];
/* L170: */
			}
		    }
/* L180: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *n; j >= 2; --j) {
		    ctemp = c__[j - 1];
		    stemp = s[j - 1];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = ctemp * temp - stemp * a[
				    i__ + a_dim1];
			    a[i__ + a_dim1] = stemp * temp + ctemp * a[i__ + 
				    a_dim1];
/* L190: */
			}
		    }
/* L200: */
		}
	    }
	} else if (lsame_(pivot, "B")) {
	    if (lsame_(direct, "F")) {
		i__1 = *n - 1;
		for (j = 1; j <= i__1; ++j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__2 = *m;
			for (i__ = 1; i__ <= i__2; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1]
				     + ctemp * temp;
			    a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * 
				    a_dim1] - stemp * temp;
/* L210: */
			}
		    }
/* L220: */
		}
	    } else if (lsame_(direct, "B")) {
		for (j = *n - 1; j >= 1; --j) {
		    ctemp = c__[j];
		    stemp = s[j];
		    if (ctemp != 1. || stemp != 0.) {
			i__1 = *m;
			for (i__ = 1; i__ <= i__1; ++i__) {
			    temp = a[i__ + j * a_dim1];
			    a[i__ + j * a_dim1] = stemp * a[i__ + *n * a_dim1]
				     + ctemp * temp;
			    a[i__ + *n * a_dim1] = ctemp * a[i__ + *n * 
				    a_dim1] - stemp * temp;
/* L230: */
			}
		    }
/* L240: */
		}
	    }
	}
    }

    return 0;

/*     End of DLASR */

} /* dlasr_ */