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Mise à jour globale de Lapack 3.2.2.

    1:       DOUBLE PRECISION FUNCTION DDOT(N,DX,INCX,DY,INCY)
    2: *     .. Scalar Arguments ..
    3:       INTEGER INCX,INCY,N
    4: *     ..
    5: *     .. Array Arguments ..
    6:       DOUBLE PRECISION DX(*),DY(*)
    7: *     ..
    8: *
    9: *  Purpose
   10: *  =======
   11: *
   12: *     DDOT forms the dot product of two vectors.
   13: *     uses unrolled loops for increments equal to one.
   14: *
   15: *  Further Details
   16: *  ===============
   17: *
   18: *     jack dongarra, linpack, 3/11/78.
   19: *     modified 12/3/93, array(1) declarations changed to array(*)
   20: *
   21: *  =====================================================================
   22: *
   23: *     .. Local Scalars ..
   24:       DOUBLE PRECISION DTEMP
   25:       INTEGER I,IX,IY,M,MP1
   26: *     ..
   27: *     .. Intrinsic Functions ..
   28:       INTRINSIC MOD
   29: *     ..
   30:       DDOT = 0.0d0
   31:       DTEMP = 0.0d0
   32:       IF (N.LE.0) RETURN
   33:       IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20
   34: *
   35: *        code for unequal increments or equal increments
   36: *          not equal to 1
   37: *
   38:       IX = 1
   39:       IY = 1
   40:       IF (INCX.LT.0) IX = (-N+1)*INCX + 1
   41:       IF (INCY.LT.0) IY = (-N+1)*INCY + 1
   42:       DO 10 I = 1,N
   43:           DTEMP = DTEMP + DX(IX)*DY(IY)
   44:           IX = IX + INCX
   45:           IY = IY + INCY
   46:    10 CONTINUE
   47:       DDOT = DTEMP
   48:       RETURN
   49: *
   50: *        code for both increments equal to 1
   51: *
   52: *
   53: *        clean-up loop
   54: *
   55:    20 M = MOD(N,5)
   56:       IF (M.EQ.0) GO TO 40
   57:       DO 30 I = 1,M
   58:           DTEMP = DTEMP + DX(I)*DY(I)
   59:    30 CONTINUE
   60:       IF (N.LT.5) GO TO 60
   61:    40 MP1 = M + 1
   62:       DO 50 I = MP1,N,5
   63:           DTEMP = DTEMP + DX(I)*DY(I) + DX(I+1)*DY(I+1) +
   64:      +            DX(I+2)*DY(I+2) + DX(I+3)*DY(I+3) + DX(I+4)*DY(I+4)
   65:    50 CONTINUE
   66:    60 DDOT = DTEMP
   67:       RETURN
   68:       END