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Patches pour OS/2

    1:       DOUBLE PRECISION FUNCTION DSDOT(N,SX,INCX,SY,INCY)
    2: *     .. Scalar Arguments ..
    3:       INTEGER INCX,INCY,N
    4: *     ..
    5: *     .. Array Arguments ..
    6:       REAL SX(*),SY(*)
    7: *     ..
    8: *
    9: *  AUTHORS
   10: *  =======
   11: *  Lawson, C. L., (JPL), Hanson, R. J., (SNLA), 
   12: *  Kincaid, D. R., (U. of Texas), Krogh, F. T., (JPL)
   13: *
   14: *  Purpose
   15: *  =======
   16: *  Compute the inner product of two vectors with extended
   17: *  precision accumulation and result.
   18: *
   19: *  Returns D.P. dot product accumulated in D.P., for S.P. SX and SY
   20: *  DSDOT = sum for I = 0 to N-1 of  SX(LX+I*INCX) * SY(LY+I*INCY),
   21: *  where LX = 1 if INCX .GE. 0, else LX = 1+(1-N)*INCX, and LY is
   22: *  defined in a similar way using INCY.
   23: *
   24: *  Arguments
   25: *  =========
   26: *
   27: *  N      (input) INTEGER
   28: *         number of elements in input vector(s)
   29: *
   30: *  SX     (input) REAL array, dimension(N)
   31: *         single precision vector with N elements
   32: *
   33: *  INCX   (input) INTEGER
   34: *          storage spacing between elements of SX
   35: *
   36: *  SY     (input) REAL array, dimension(N)
   37: *         single precision vector with N elements
   38: *
   39: *  INCY   (input) INTEGER
   40: *         storage spacing between elements of SY
   41: *
   42: *  DSDOT  (output) DOUBLE PRECISION
   43: *         DSDOT  double precision dot product (zero if N.LE.0)
   44: *
   45: *  Further Details
   46: *  ===============
   47: *
   48: *  REFERENCES
   49: *      
   50: *  C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T.
   51: *  Krogh, Basic linear algebra subprograms for Fortran
   52: *  usage, Algorithm No. 539, Transactions on Mathematical
   53: *  Software 5, 3 (September 1979), pp. 308-323.
   54: *
   55: *  REVISION HISTORY  (YYMMDD)
   56: *
   57: *  791001  DATE WRITTEN
   58: *  890831  Modified array declarations.  (WRB)
   59: *  890831  REVISION DATE from Version 3.2
   60: *  891214  Prologue converted to Version 4.0 format.  (BAB)
   61: *  920310  Corrected definition of LX in DESCRIPTION.  (WRB)
   62: *  920501  Reformatted the REFERENCES section.  (WRB)
   63: *  070118  Reformat to LAPACK style (JL)
   64: *
   65: *  =====================================================================
   66: *
   67: *     .. Local Scalars ..
   68:       INTEGER I,KX,KY,NS
   69: *     ..
   70: *     .. Intrinsic Functions ..
   71:       INTRINSIC DBLE
   72: *     ..
   73:       DSDOT = 0.0D0
   74:       IF (N.LE.0) RETURN
   75:       IF (INCX.EQ.INCY .AND. INCX.GT.0) GO TO 20
   76: *
   77: *     Code for unequal or nonpositive increments.
   78: *
   79:       KX = 1
   80:       KY = 1
   81:       IF (INCX.LT.0) KX = 1 + (1-N)*INCX
   82:       IF (INCY.LT.0) KY = 1 + (1-N)*INCY
   83:       DO 10 I = 1,N
   84:           DSDOT = DSDOT + DBLE(SX(KX))*DBLE(SY(KY))
   85:           KX = KX + INCX
   86:           KY = KY + INCY
   87:    10 CONTINUE
   88:       RETURN
   89: *
   90: *     Code for equal, positive, non-unit increments.
   91: *
   92:    20 NS = N*INCX
   93:       DO 30 I = 1,NS,INCX
   94:           DSDOT = DSDOT + DBLE(SX(I))*DBLE(SY(I))
   95:    30 CONTINUE
   96:       RETURN
   97:       END