/*  -- translated by f2c (version 19940927).

   You must link the resulting object file with the libraries:

	-lf2c -lm   (in that order)

*/

#include "f2c.h"

/* Subroutine */ int sger_(integer *m, integer *n, real *alpha, real *x, 

	integer *incx, real *y, integer *incy, real *a, integer *lda)

{

    /* System generated locals */

    integer a_dim1, a_offset, i__1, i__2;

    /* Local variables */

    static integer info;

    static real temp;

    static integer i, j, ix, jy, kx;

    extern /* Subroutine */ int xerbla_(char *, integer *);

/*  Purpose   

    =======   

    SGER   performs the rank 1 operation   

       A := alpha*x*y' + A,   

    where alpha is a scalar, x is an m element vector, y is an n element 

    vector and A is an m by n matrix.   

    Parameters   

    ==========   

    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.   

    ALPHA  - REAL            .   

             On entry, ALPHA specifies the scalar alpha.   

             Unchanged on exit.   

    X      - REAL             array of dimension at least   

             ( 1 + ( m - 1 )*abs( INCX ) ).   

             Before entry, the incremented array X must contain the m   

             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.   

    Y      - REAL             array of dimension at least   

             ( 1 + ( n - 1 )*abs( INCY ) ).   

             Before entry, the incremented array Y must contain the n   

             element vector y.   

             Unchanged on exit.   

    INCY   - INTEGER.   

             On entry, INCY specifies the increment for the elements of   

             Y. INCY must not be zero.   

             Unchanged on exit.   

    A      - REAL             array of DIMENSION ( LDA, n ).   

             Before entry, the leading m by n part of the array A must   

             contain the matrix of coefficients. On exit, A is   

             overwritten by 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, m ).   

             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   

       Function Body */

#define X(I) x[(I)-1]

#define Y(I) y[(I)-1]

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

    info = 0;

    if (*m < 0) {

	info = 1;

    } else if (*n < 0) {

	info = 2;

    } else if (*incx == 0) {

	info = 5;

    } else if (*incy == 0) {

	info = 7;

    } else if (*lda < max(1,*m)) {

	info = 9;

    }

    if (info != 0) {

	xerbla_("SGER  ", &info);

	return 0;

    }

/*     Quick return if possible. */

    if (*m == 0 || *n == 0 || *alpha == 0.f) {

	return 0;

    }

/*     Start the operations. In this version the elements of A are   

       accessed sequentially with one pass through A. */

    if (*incy > 0) {

	jy = 1;

    } else {

	jy = 1 - (*n - 1) * *incy;

    }

    if (*incx == 1) {

	i__1 = *n;

	for (j = 1; j <= *n; ++j) {

	    if (Y(jy) != 0.f) {

		temp = *alpha * Y(jy);

		i__2 = *m;

		for (i = 1; i <= *m; ++i) {

		    A(i,j) += X(i) * temp;

/* L10: */

		}

	    }

	    jy += *incy;

/* L20: */

	}

    } else {

	if (*incx > 0) {

	    kx = 1;

	} else {

	    kx = 1 - (*m - 1) * *incx;

	}

	i__1 = *n;

	for (j = 1; j <= *n; ++j) {

	    if (Y(jy) != 0.f) {

		temp = *alpha * Y(jy);

		ix = kx;

		i__2 = *m;

		for (i = 1; i <= *m; ++i) {

		    A(i,j) += X(ix) * temp;

		    ix += *incx;

/* L30: */

		}

	    }

	    jy += *incy;

/* L40: */

	}

    }

    return 0;

/*     End of SGER  . */

} /* sger_ */