version 1.6, 2010/12/21 13:51:24
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version 1.7, 2011/07/22 07:38:01
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Line 30
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Line 30
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DDOT = 0.0d0 |
DDOT = 0.0d0 |
DTEMP = 0.0d0 |
DTEMP = 0.0d0 |
IF (N.LE.0) RETURN |
IF (N.LE.0) RETURN |
IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20 |
IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN |
* |
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* code for unequal increments or equal increments |
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* not equal to 1 |
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* |
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IX = 1 |
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IY = 1 |
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IF (INCX.LT.0) IX = (-N+1)*INCX + 1 |
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IF (INCY.LT.0) IY = (-N+1)*INCY + 1 |
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DO 10 I = 1,N |
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DTEMP = DTEMP + DX(IX)*DY(IY) |
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IX = IX + INCX |
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IY = IY + INCY |
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10 CONTINUE |
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DDOT = DTEMP |
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RETURN |
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* |
* |
* code for both increments equal to 1 |
* code for both increments equal to 1 |
* |
* |
* |
* |
* clean-up loop |
* clean-up loop |
* |
* |
20 M = MOD(N,5) |
M = MOD(N,5) |
IF (M.EQ.0) GO TO 40 |
IF (M.NE.0) THEN |
DO 30 I = 1,M |
DO I = 1,M |
DTEMP = DTEMP + DX(I)*DY(I) |
DTEMP = DTEMP + DX(I)*DY(I) |
30 CONTINUE |
END DO |
IF (N.LT.5) GO TO 60 |
IF (N.LT.5) THEN |
40 MP1 = M + 1 |
DDOT=DTEMP |
DO 50 I = MP1,N,5 |
RETURN |
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END IF |
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END IF |
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MP1 = M + 1 |
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DO I = MP1,N,5 |
DTEMP = DTEMP + DX(I)*DY(I) + DX(I+1)*DY(I+1) + |
DTEMP = DTEMP + DX(I)*DY(I) + DX(I+1)*DY(I+1) + |
+ DX(I+2)*DY(I+2) + DX(I+3)*DY(I+3) + DX(I+4)*DY(I+4) |
$ DX(I+2)*DY(I+2) + DX(I+3)*DY(I+3) + DX(I+4)*DY(I+4) |
50 CONTINUE |
END DO |
60 DDOT = DTEMP |
ELSE |
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* |
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* code for unequal increments or equal increments |
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* not equal to 1 |
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* |
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IX = 1 |
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IY = 1 |
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IF (INCX.LT.0) IX = (-N+1)*INCX + 1 |
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IF (INCY.LT.0) IY = (-N+1)*INCY + 1 |
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DO I = 1,N |
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DTEMP = DTEMP + DX(IX)*DY(IY) |
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IX = IX + INCX |
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IY = IY + INCY |
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END DO |
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END IF |
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DDOT = DTEMP |
RETURN |
RETURN |
END |
END |