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

doublereal sdsdot_(integer *n, real *sb, real *sx, integer *incx, real *sy, 
	integer *incy)
{
    /* System generated locals */
    integer i__1, i__2;
    real ret_val;
    /* Local variables */
    static integer i__, ns, kx, ky;
    static doublereal dsdot;
/*  PURPOSE   
    =======   
    Compute the inner product of two vectors with extended   
    precision accumulation.   
    Returns S.P. result with dot product accumulated in D.P.   
    SDSDOT = SB + sum for I = 0 to N-1 of SX(LX+I*INCX)*SY(LY+I*INCY),   
    where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is   
    defined in a similar way using INCY.   
    AUTHOR   
    ======   
    Lawson, C. L., (JPL), Hanson, R. J., (SNLA),   
    Kincaid, D. R., (U. of Texas), Krogh, F. T., (JPL)   
    ARGUMENTS   
    =========   
    N      (input) INTEGER   
           number of elements in input vector(s)   
    SB     (input) REAL   
           single precision scalar to be added to inner product   
    SX     (input) REAL array, dimension (N)   
           single precision vector with N elements   
    INCX   (input) INTEGER   
           storage spacing between elements of SX   
    SY     (input) REAL array, dimension (N)   
           single precision vector with N elements   
    INCY   (input) INTEGER   
           storage spacing between elements of SY   
    SDSDOT (output) REAL   
           single precision dot product (SB if N .LE. 0)   
    REFERENCES   
    ==========   
    C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T.   
    Krogh, Basic linear algebra subprograms for Fortran   
    usage, Algorithm No. 539, Transactions on Mathematical   
    Software 5, 3 (September 1979), pp. 308-323.   
    REVISION HISTORY  (YYMMDD)   
    ==========================   
    791001  DATE WRITTEN   
    890531  Changed all specific intrinsics to generic.  (WRB)   
    890831  Modified array declarations.  (WRB)   
    890831  REVISION DATE from Version 3.2   
    891214  Prologue converted to Version 4.0 format.  (BAB)   
    920310  Corrected definition of LX in DESCRIPTION.  (WRB)   
    920501  Reformatted the REFERENCES section.  (WRB)   
    070118  Reformat to LAPACK coding style   
    =====================================================================   
       Parameter adjustments */
    --sy;
    --sx;
    /* Function Body */
    dsdot = *sb;
    if (*n <= 0) {
	goto L30;
    }
    if (*incx == *incy && *incx > 0) {
	goto L40;
    }
/*     Code for unequal or nonpositive increments. */
    kx = 1;
    ky = 1;
    if (*incx < 0) {
	kx = (1 - *n) * *incx + 1;
    }
    if (*incy < 0) {
	ky = (1 - *n) * *incy + 1;
    }
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	dsdot += (doublereal) sx[kx] * (doublereal) sy[ky];
	kx += *incx;
	ky += *incy;
/* L10: */
    }
L30:
    ret_val = dsdot;
    return ret_val;
/*     Code for equal and positive increments. */
L40:
    ns = *n * *incx;
    i__1 = ns;
    i__2 = *incx;
    for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
	dsdot += (doublereal) sx[i__] * (doublereal) sy[i__];
/* L50: */
    }
    ret_val = dsdot;
    return ret_val;
} /* sdsdot_ */