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

/* Subroutine */ int zgbmv_(char *trans, integer *m, integer *n, integer *kl, 
	integer *ku, doublecomplex *alpha, doublecomplex *a, integer *lda, 
	doublecomplex *x, integer *incx, doublecomplex *beta, doublecomplex *
	y, integer *incy)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6;
    doublecomplex z__1, z__2, z__3;
    /* Builtin functions */
    void d_cnjg(doublecomplex *, doublecomplex *);
    /* Local variables */
    static integer info;
    static doublecomplex temp;
    static integer lenx, leny, i__, j, k;
    extern logical lsame_(char *, char *);
    static integer ix, iy, jx, jy, kx, ky;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static logical noconj;
    static integer kup1;
#define a_subscr(a_1,a_2) (a_2)*a_dim1 + a_1
#define a_ref(a_1,a_2) a[a_subscr(a_1,a_2)]
/*  Purpose   
    =======   
    ZGBMV  performs one of the matrix-vector operations   
       y := alpha*A*x + beta*y,   or   y := alpha*A'*x + beta*y,   or   
       y := alpha*conjg( A' )*x + beta*y,   
    where alpha and beta are scalars, x and y are vectors and A is an   
    m by n band matrix, with kl sub-diagonals and ku super-diagonals.   
    Parameters   
    ==========   
    TRANS  - CHARACTER*1.   
             On entry, TRANS specifies the operation to be performed as   
             follows:   
                TRANS = 'N' or 'n'   y := alpha*A*x + beta*y.   
                TRANS = 'T' or 't'   y := alpha*A'*x + beta*y.   
                TRANS = 'C' or 'c'   y := alpha*conjg( A' )*x + beta*y.   
             Unchanged on exit.   
    M      - INTEGER.   
             On entry, M specifies the number of rows of the matrix A.   
             M must be at least zero.   
             Unchanged on exit.   
    N      - INTEGER.   
             On entry, N specifies the number of columns of the matrix A.   
             N must be at least zero.   
             Unchanged on exit.   
    KL     - INTEGER.   
             On entry, KL specifies the number of sub-diagonals of the   
             matrix A. KL must satisfy  0 .le. KL.   
             Unchanged on exit.   
    KU     - INTEGER.   
             On entry, KU specifies the number of super-diagonals of the   
             matrix A. KU must satisfy  0 .le. KU.   
             Unchanged on exit.   
    ALPHA  - COMPLEX*16      .   
             On entry, ALPHA specifies the scalar alpha.   
             Unchanged on exit.   
    A      - COMPLEX*16       array of DIMENSION ( LDA, n ).   
             Before entry, the leading ( kl + ku + 1 ) by n part of the   
             array A must contain the matrix of coefficients, supplied   
             column by column, with the leading diagonal of the matrix in   
             row ( ku + 1 ) of the array, the first super-diagonal   
             starting at position 2 in row ku, the first sub-diagonal   
             starting at position 1 in row ( ku + 2 ), and so on.   
             Elements in the array A that do not correspond to elements   
             in the band matrix (such as the top left ku by ku triangle)   
             are not referenced.   
             The following program segment will transfer a band matrix   
             from conventional full matrix storage to band storage:   
                   DO 20, J = 1, N   
                      K = KU + 1 - J   
                      DO 10, I = MAX( 1, J - KU ), MIN( M, J + KL )   
                         A( K + I, J ) = matrix( I, J )   
                10    CONTINUE   
                20 CONTINUE   
             Unchanged on exit.   
    LDA    - INTEGER.   
             On entry, LDA specifies the first dimension of A as declared   
             in the calling (sub) program. LDA must be at least   
             ( kl + ku + 1 ).   
             Unchanged on exit.   
    X      - COMPLEX*16       array of DIMENSION at least   
             ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'   
             and at least   
             ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.   
             Before entry, the incremented array X must contain the   
             vector x.   
             Unchanged on exit.   
    INCX   - INTEGER.   
             On entry, INCX specifies the increment for the elements of   
             X. INCX must not be zero.   
             Unchanged on exit.   
    BETA   - COMPLEX*16      .   
             On entry, BETA specifies the scalar beta. When BETA is   
             supplied as zero then Y need not be set on input.   
             Unchanged on exit.   
    Y      - COMPLEX*16       array of DIMENSION at least   
             ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'   
             and at least   
             ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.   
             Before entry, the incremented array Y must contain the   
             vector y. On exit, Y is overwritten by the updated vector y.   
    INCY   - INTEGER.   
             On entry, INCY specifies the increment for the elements of   
             Y. INCY must not be zero.   
             Unchanged on exit.   
    Level 2 Blas routine.   
    -- Written on 22-October-1986.   
       Jack Dongarra, Argonne National Lab.   
       Jeremy Du Croz, Nag Central Office.   
       Sven Hammarling, Nag Central Office.   
       Richard Hanson, Sandia National Labs.   
       Test the input parameters.   
       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --x;
    --y;
    /* Function Body */
    info = 0;
    if (! lsame_(trans, "N") && ! lsame_(trans, "T") && ! lsame_(trans, "C")
	    ) {
	info = 1;
    } else if (*m < 0) {
	info = 2;
    } else if (*n < 0) {
	info = 3;
    } else if (*kl < 0) {
	info = 4;
    } else if (*ku < 0) {
	info = 5;
    } else if (*lda < *kl + *ku + 1) {
	info = 8;
    } else if (*incx == 0) {
	info = 10;
    } else if (*incy == 0) {
	info = 13;
    }
    if (info != 0) {
	xerbla_("ZGBMV ", &info);
	return 0;
    }
/*     Quick return if possible. */
    if (*m == 0 || *n == 0 || alpha->r == 0. && alpha->i == 0. && (beta->r == 
	    1. && beta->i == 0.)) {
	return 0;
    }
    noconj = lsame_(trans, "T");
/*     Set  LENX  and  LENY, the lengths of the vectors x and y, and set   
       up the start points in  X  and  Y. */
    if (lsame_(trans, "N")) {
	lenx = *n;
	leny = *m;
    } else {
	lenx = *m;
	leny = *n;
    }
    if (*incx > 0) {
	kx = 1;
    } else {
	kx = 1 - (lenx - 1) * *incx;
    }
    if (*incy > 0) {
	ky = 1;
    } else {
	ky = 1 - (leny - 1) * *incy;
    }
/*     Start the operations. In this version the elements of A are   
       accessed sequentially with one pass through the band part of A.   
       First form  y := beta*y. */
    if (beta->r != 1. || beta->i != 0.) {
	if (*incy == 1) {
	    if (beta->r == 0. && beta->i == 0.) {
		i__1 = leny;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    i__2 = i__;
		    y[i__2].r = 0., y[i__2].i = 0.;
/* L10: */
		}
	    } else {
		i__1 = leny;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    i__2 = i__;
		    i__3 = i__;
		    z__1.r = beta->r * y[i__3].r - beta->i * y[i__3].i, 
			    z__1.i = beta->r * y[i__3].i + beta->i * y[i__3]
			    .r;
		    y[i__2].r = z__1.r, y[i__2].i = z__1.i;
/* L20: */
		}
	    }
	} else {
	    iy = ky;
	    if (beta->r == 0. && beta->i == 0.) {
		i__1 = leny;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    i__2 = iy;
		    y[i__2].r = 0., y[i__2].i = 0.;
		    iy += *incy;
/* L30: */
		}
	    } else {
		i__1 = leny;
		for (i__ = 1; i__ <= i__1; ++i__) {
		    i__2 = iy;
		    i__3 = iy;
		    z__1.r = beta->r * y[i__3].r - beta->i * y[i__3].i, 
			    z__1.i = beta->r * y[i__3].i + beta->i * y[i__3]
			    .r;
		    y[i__2].r = z__1.r, y[i__2].i = z__1.i;
		    iy += *incy;
/* L40: */
		}
	    }
	}
    }
    if (alpha->r == 0. && alpha->i == 0.) {
	return 0;
    }
    kup1 = *ku + 1;
    if (lsame_(trans, "N")) {
/*        Form  y := alpha*A*x + y. */
	jx = kx;
	if (*incy == 1) {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = jx;
		if (x[i__2].r != 0. || x[i__2].i != 0.) {
		    i__2 = jx;
		    z__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, 
			    z__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
			    .r;
		    temp.r = z__1.r, temp.i = z__1.i;
		    k = kup1 - j;
/* Computing MAX */
		    i__2 = 1, i__3 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__4 = min(i__5,i__6);
		    for (i__ = max(i__2,i__3); i__ <= i__4; ++i__) {
			i__2 = i__;
			i__3 = i__;
			i__5 = a_subscr(k + i__, j);
			z__2.r = temp.r * a[i__5].r - temp.i * a[i__5].i, 
				z__2.i = temp.r * a[i__5].i + temp.i * a[i__5]
				.r;
			z__1.r = y[i__3].r + z__2.r, z__1.i = y[i__3].i + 
				z__2.i;
			y[i__2].r = z__1.r, y[i__2].i = z__1.i;
/* L50: */
		    }
		}
		jx += *incx;
/* L60: */
	    }
	} else {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__4 = jx;
		if (x[i__4].r != 0. || x[i__4].i != 0.) {
		    i__4 = jx;
		    z__1.r = alpha->r * x[i__4].r - alpha->i * x[i__4].i, 
			    z__1.i = alpha->r * x[i__4].i + alpha->i * x[i__4]
			    .r;
		    temp.r = z__1.r, temp.i = z__1.i;
		    iy = ky;
		    k = kup1 - j;
/* Computing MAX */
		    i__4 = 1, i__2 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__3 = min(i__5,i__6);
		    for (i__ = max(i__4,i__2); i__ <= i__3; ++i__) {
			i__4 = iy;
			i__2 = iy;
			i__5 = a_subscr(k + i__, j);
			z__2.r = temp.r * a[i__5].r - temp.i * a[i__5].i, 
				z__2.i = temp.r * a[i__5].i + temp.i * a[i__5]
				.r;
			z__1.r = y[i__2].r + z__2.r, z__1.i = y[i__2].i + 
				z__2.i;
			y[i__4].r = z__1.r, y[i__4].i = z__1.i;
			iy += *incy;
/* L70: */
		    }
		}
		jx += *incx;
		if (j > *ku) {
		    ky += *incy;
		}
/* L80: */
	    }
	}
    } else {
/*        Form  y := alpha*A'*x + y  or  y := alpha*conjg( A' )*x + y. */
	jy = ky;
	if (*incx == 1) {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		temp.r = 0., temp.i = 0.;
		k = kup1 - j;
		if (noconj) {
/* Computing MAX */
		    i__3 = 1, i__4 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__2 = min(i__5,i__6);
		    for (i__ = max(i__3,i__4); i__ <= i__2; ++i__) {
			i__3 = a_subscr(k + i__, j);
			i__4 = i__;
			z__2.r = a[i__3].r * x[i__4].r - a[i__3].i * x[i__4]
				.i, z__2.i = a[i__3].r * x[i__4].i + a[i__3]
				.i * x[i__4].r;
			z__1.r = temp.r + z__2.r, z__1.i = temp.i + z__2.i;
			temp.r = z__1.r, temp.i = z__1.i;
/* L90: */
		    }
		} else {
/* Computing MAX */
		    i__2 = 1, i__3 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__4 = min(i__5,i__6);
		    for (i__ = max(i__2,i__3); i__ <= i__4; ++i__) {
			d_cnjg(&z__3, &a_ref(k + i__, j));
			i__2 = i__;
			z__2.r = z__3.r * x[i__2].r - z__3.i * x[i__2].i, 
				z__2.i = z__3.r * x[i__2].i + z__3.i * x[i__2]
				.r;
			z__1.r = temp.r + z__2.r, z__1.i = temp.i + z__2.i;
			temp.r = z__1.r, temp.i = z__1.i;
/* L100: */
		    }
		}
		i__4 = jy;
		i__2 = jy;
		z__2.r = alpha->r * temp.r - alpha->i * temp.i, z__2.i = 
			alpha->r * temp.i + alpha->i * temp.r;
		z__1.r = y[i__2].r + z__2.r, z__1.i = y[i__2].i + z__2.i;
		y[i__4].r = z__1.r, y[i__4].i = z__1.i;
		jy += *incy;
/* L110: */
	    }
	} else {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		temp.r = 0., temp.i = 0.;
		ix = kx;
		k = kup1 - j;
		if (noconj) {
/* Computing MAX */
		    i__4 = 1, i__2 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__3 = min(i__5,i__6);
		    for (i__ = max(i__4,i__2); i__ <= i__3; ++i__) {
			i__4 = a_subscr(k + i__, j);
			i__2 = ix;
			z__2.r = a[i__4].r * x[i__2].r - a[i__4].i * x[i__2]
				.i, z__2.i = a[i__4].r * x[i__2].i + a[i__4]
				.i * x[i__2].r;
			z__1.r = temp.r + z__2.r, z__1.i = temp.i + z__2.i;
			temp.r = z__1.r, temp.i = z__1.i;
			ix += *incx;
/* L120: */
		    }
		} else {
/* Computing MAX */
		    i__3 = 1, i__4 = j - *ku;
/* Computing MIN */
		    i__5 = *m, i__6 = j + *kl;
		    i__2 = min(i__5,i__6);
		    for (i__ = max(i__3,i__4); i__ <= i__2; ++i__) {
			d_cnjg(&z__3, &a_ref(k + i__, j));
			i__3 = ix;
			z__2.r = z__3.r * x[i__3].r - z__3.i * x[i__3].i, 
				z__2.i = z__3.r * x[i__3].i + z__3.i * x[i__3]
				.r;
			z__1.r = temp.r + z__2.r, z__1.i = temp.i + z__2.i;
			temp.r = z__1.r, temp.i = z__1.i;
			ix += *incx;
/* L130: */
		    }
		}
		i__2 = jy;
		i__3 = jy;
		z__2.r = alpha->r * temp.r - alpha->i * temp.i, z__2.i = 
			alpha->r * temp.i + alpha->i * temp.r;
		z__1.r = y[i__3].r + z__2.r, z__1.i = y[i__3].i + z__2.i;
		y[i__2].r = z__1.r, y[i__2].i = z__1.i;
		jy += *incy;
		if (j > *ku) {
		    kx += *incx;
		}
/* L140: */
	    }
	}
    }
    return 0;
/*     End of ZGBMV . */
} /* zgbmv_ */
#undef a_ref
#undef a_subscr

