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

/* Subroutine */ int csyr_(char *uplo, integer *n, complex *alpha, complex *x,
	 integer *incx, complex *a, integer *lda)
{
/*  -- LAPACK auxiliary routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       October 31, 1992   


    Purpose   
    =======   

    CSYR   performs the symmetric rank 1 operation   

       A := alpha*x*( x' ) + A,   

    where alpha is a complex scalar, x is an n element vector and A is an   
    n by n symmetric 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  - COMPLEX   
             On entry, ALPHA specifies the scalar alpha.   
             Unchanged on exit.   

    X      - COMPLEX array, 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 array, 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 symmetric 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 symmetric 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.   

    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.   

   =====================================================================   


       Test the input parameters.   

       Parameter adjustments */
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
    complex q__1, q__2;
    /* Local variables */
    static integer info;
    static complex temp;
    static integer i__, j;
    extern logical lsame_(char *, char *);
    static integer ix, jx, kx;
    extern /* Subroutine */ int xerbla_(char *, integer *);
#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)]

    --x;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    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_("CSYR  ", &info);
	return 0;
    }

/*     Quick return if possible. */

    if (*n == 0 || alpha->r == 0.f && alpha->i == 0.f) {
	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.f || x[i__2].i != 0.f) {
		    i__2 = j;
		    q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, 
			    q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
			    .r;
		    temp.r = q__1.r, temp.i = q__1.i;
		    i__2 = j;
		    for (i__ = 1; i__ <= i__2; ++i__) {
			i__3 = a_subscr(i__, j);
			i__4 = a_subscr(i__, j);
			i__5 = i__;
			q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				q__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			q__1.r = a[i__4].r + q__2.r, q__1.i = a[i__4].i + 
				q__2.i;
			a[i__3].r = q__1.r, a[i__3].i = q__1.i;
/* L10: */
		    }
		}
/* L20: */
	    }
	} else {
	    jx = kx;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = jx;
		if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
		    i__2 = jx;
		    q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, 
			    q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
			    .r;
		    temp.r = q__1.r, temp.i = q__1.i;
		    ix = kx;
		    i__2 = j;
		    for (i__ = 1; i__ <= i__2; ++i__) {
			i__3 = a_subscr(i__, j);
			i__4 = a_subscr(i__, j);
			i__5 = ix;
			q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				q__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			q__1.r = a[i__4].r + q__2.r, q__1.i = a[i__4].i + 
				q__2.i;
			a[i__3].r = q__1.r, a[i__3].i = q__1.i;
			ix += *incx;
/* L30: */
		    }
		}
		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.f || x[i__2].i != 0.f) {
		    i__2 = j;
		    q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, 
			    q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
			    .r;
		    temp.r = q__1.r, temp.i = q__1.i;
		    i__2 = *n;
		    for (i__ = j; i__ <= i__2; ++i__) {
			i__3 = a_subscr(i__, j);
			i__4 = a_subscr(i__, j);
			i__5 = i__;
			q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				q__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			q__1.r = a[i__4].r + q__2.r, q__1.i = a[i__4].i + 
				q__2.i;
			a[i__3].r = q__1.r, a[i__3].i = q__1.i;
/* L50: */
		    }
		}
/* L60: */
	    }
	} else {
	    jx = kx;
	    i__1 = *n;
	    for (j = 1; j <= i__1; ++j) {
		i__2 = jx;
		if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
		    i__2 = jx;
		    q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, 
			    q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
			    .r;
		    temp.r = q__1.r, temp.i = q__1.i;
		    ix = jx;
		    i__2 = *n;
		    for (i__ = j; i__ <= i__2; ++i__) {
			i__3 = a_subscr(i__, j);
			i__4 = a_subscr(i__, j);
			i__5 = ix;
			q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i, 
				q__2.i = x[i__5].r * temp.i + x[i__5].i * 
				temp.r;
			q__1.r = a[i__4].r + q__2.r, q__1.i = a[i__4].i + 
				q__2.i;
			a[i__3].r = q__1.r, a[i__3].i = q__1.i;
			ix += *incx;
/* L70: */
		    }
		}
		jx += *incx;
/* L80: */
	    }
	}
    }

    return 0;

/*     End of CSYR */

} /* csyr_ */

#undef a_ref
#undef a_subscr


