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

/* Subroutine */ int zher_(char *uplo, integer *n, doublereal *alpha, 
	doublecomplex *x, integer *incx, doublecomplex *a, integer *lda)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
    doublereal d__1;
    doublecomplex z__1, z__2;
    /* Builtin functions */
    void d_cnjg(doublecomplex *, doublecomplex *);
    /* Local variables */
    static integer i__, j, ix, jx, kx, info;
    static doublecomplex temp;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int xerbla_(char *, integer *);
/*  Purpose   
    =======   
    ZHER   performs the hermitian rank 1 operation   
       A := alpha*x*conjg( x' ) + A,   
    where alpha is a real scalar, x is an n element vector and A is an   
    n by n hermitian matrix.   
    Arguments   
    ==========   
    UPLO   - CHARACTER*1.   
             On entry, UPLO specifies whether the upper or lower   
             triangular part of the array A is to be referenced as   
             follows:   
                UPLO = 'U' or 'u'   Only the upper triangular part of A   
                                    is to be referenced.   
                UPLO = 'L' or 'l'   Only the lower triangular part of A   
                                    is to be referenced.   
             Unchanged on exit.   
    N      - INTEGER.   
             On entry, N specifies the order of the matrix A.   
             N must be at least zero.   
             Unchanged on exit.   
    ALPHA  - DOUBLE PRECISION.   
             On entry, ALPHA specifies the scalar alpha.   
             Unchanged on exit.   
    X      - COMPLEX*16       array of dimension at least   
             ( 1 + ( n - 1 )*abs( INCX ) ).   
             Before entry, the incremented array X must contain the n   
             element 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.   
    A      - COMPLEX*16       array of DIMENSION ( LDA, n ).   
             Before entry with  UPLO = 'U' or 'u', the leading n by n   
             upper triangular part of the array A must contain the upper   
             triangular part of the hermitian matrix and the strictly   
             lower triangular part of A is not referenced. On exit, the   
             upper triangular part of the array A is overwritten by the   
             upper triangular part of the updated matrix.   
             Before entry with UPLO = 'L' or 'l', the leading n by n   
             lower triangular part of the array A must contain the lower   
             triangular part of the hermitian matrix and the strictly   
             upper triangular part of A is not referenced. On exit, the   
             lower triangular part of the array A is overwritten by the   
             lower triangular part of the updated matrix.   
             Note that the imaginary parts of the diagonal elements need   
             not be set, they are assumed to be zero, and on exit they   
             are set to zero.   
    LDA    - INTEGER.   
             On entry, LDA specifies the first dimension of A as declared   
             in the calling (sub) program. LDA must be at least   
             max( 1, n ).   
             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 */
    --x;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    /* Function Body */
    info = 0;
    if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
	info = 1;
    } else if (*n < 0) {
	info = 2;
    } else if (*incx == 0) {
	info = 5;
    } else if (*lda < max(1,*n)) {
	info = 7;
    }
    if (info != 0) {
	xerbla_("ZHER  ", &info);
	return 0;
    }
/*     Quick return if possible. */
    if (*n == 0 || *alpha == 0.) {
	return 0;
    }
/*     Set the start point in X if the increment is not unity. */
    if (*incx <= 0) {
	kx = 1 - (*n - 1) * *incx;
    } else if (*incx != 1) {
	kx = 1;
    }
/*     Start the operations. In this version the elements of A are   
       accessed sequentially with one pass through the triangular part   
       of A. */
    if (lsame_(uplo, "U")) {
/*        Form  A  when A is stored in upper triangle. */
	if (*incx == 1) {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = j;
		if (x[i__2].r != 0. || x[i__2].i != 0.) {
		    d_cnjg(&z__2, &x[j]);
		    z__1.r = *alpha * z__2.r, z__1.i = *alpha * z__2.i;
		    temp.r = z__1.r, temp.i = z__1.i;
		    i__2 = j - 1;
		    for (i__ = 1; i__ <= i__2; ++i__) {
			i__3 = i__ + j * a_dim1;
			i__4 = i__ + j * a_dim1;
			i__5 = i__;
			z__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				z__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			z__1.r = a[i__4].r + z__2.r, z__1.i = a[i__4].i + 
				z__2.i;
			a[i__3].r = z__1.r, a[i__3].i = z__1.i;
/* L10: */
		    }
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    i__4 = j;
		    z__1.r = x[i__4].r * temp.r - x[i__4].i * temp.i, z__1.i =
			     x[i__4].r * temp.i + x[i__4].i * temp.r;
		    d__1 = a[i__3].r + z__1.r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		} else {
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    d__1 = a[i__3].r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		}
/* L20: */
	    }
	} else {
	    jx = kx;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = jx;
		if (x[i__2].r != 0. || x[i__2].i != 0.) {
		    d_cnjg(&z__2, &x[jx]);
		    z__1.r = *alpha * z__2.r, z__1.i = *alpha * z__2.i;
		    temp.r = z__1.r, temp.i = z__1.i;
		    ix = kx;
		    i__2 = j - 1;
		    for (i__ = 1; i__ <= i__2; ++i__) {
			i__3 = i__ + j * a_dim1;
			i__4 = i__ + j * a_dim1;
			i__5 = ix;
			z__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				z__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			z__1.r = a[i__4].r + z__2.r, z__1.i = a[i__4].i + 
				z__2.i;
			a[i__3].r = z__1.r, a[i__3].i = z__1.i;
			ix += *incx;
/* L30: */
		    }
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    i__4 = jx;
		    z__1.r = x[i__4].r * temp.r - x[i__4].i * temp.i, z__1.i =
			     x[i__4].r * temp.i + x[i__4].i * temp.r;
		    d__1 = a[i__3].r + z__1.r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		} else {
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    d__1 = a[i__3].r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		}
		jx += *incx;
/* L40: */
	    }
	}
    } else {
/*        Form  A  when A is stored in lower triangle. */
	if (*incx == 1) {
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = j;
		if (x[i__2].r != 0. || x[i__2].i != 0.) {
		    d_cnjg(&z__2, &x[j]);
		    z__1.r = *alpha * z__2.r, z__1.i = *alpha * z__2.i;
		    temp.r = z__1.r, temp.i = z__1.i;
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    i__4 = j;
		    z__1.r = temp.r * x[i__4].r - temp.i * x[i__4].i, z__1.i =
			     temp.r * x[i__4].i + temp.i * x[i__4].r;
		    d__1 = a[i__3].r + z__1.r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		    i__2 = *n;
		    for (i__ = j + 1; i__ <= i__2; ++i__) {
			i__3 = i__ + j * a_dim1;
			i__4 = i__ + j * a_dim1;
			i__5 = i__;
			z__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				z__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			z__1.r = a[i__4].r + z__2.r, z__1.i = a[i__4].i + 
				z__2.i;
			a[i__3].r = z__1.r, a[i__3].i = z__1.i;
/* L50: */
		    }
		} else {
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    d__1 = a[i__3].r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		}
/* L60: */
	    }
	} else {
	    jx = kx;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = jx;
		if (x[i__2].r != 0. || x[i__2].i != 0.) {
		    d_cnjg(&z__2, &x[jx]);
		    z__1.r = *alpha * z__2.r, z__1.i = *alpha * z__2.i;
		    temp.r = z__1.r, temp.i = z__1.i;
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    i__4 = jx;
		    z__1.r = temp.r * x[i__4].r - temp.i * x[i__4].i, z__1.i =
			     temp.r * x[i__4].i + temp.i * x[i__4].r;
		    d__1 = a[i__3].r + z__1.r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		    ix = jx;
		    i__2 = *n;
		    for (i__ = j + 1; i__ <= i__2; ++i__) {
			ix += *incx;
			i__3 = i__ + j * a_dim1;
			i__4 = i__ + j * a_dim1;
			i__5 = ix;
			z__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				z__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			z__1.r = a[i__4].r + z__2.r, z__1.i = a[i__4].i + 
				z__2.i;
			a[i__3].r = z__1.r, a[i__3].i = z__1.i;
/* L70: */
		    }
		} else {
		    i__2 = j + j * a_dim1;
		    i__3 = j + j * a_dim1;
		    d__1 = a[i__3].r;
		    a[i__2].r = d__1, a[i__2].i = 0.;
		}
		jx += *incx;
/* L80: */
	    }
	}
    }
    return 0;
/*     End of ZHER  . */
} /* zher_ */