diff options
Diffstat (limited to 'BLAS/SRC/ddot.f')
| -rw-r--r-- | BLAS/SRC/ddot.f | 58 |
1 files changed, 31 insertions, 27 deletions
diff --git a/BLAS/SRC/ddot.f b/BLAS/SRC/ddot.f index 3df03aec..33719eed 100644 --- a/BLAS/SRC/ddot.f +++ b/BLAS/SRC/ddot.f @@ -30,39 +30,43 @@ DDOT = 0.0d0 DTEMP = 0.0d0 IF (N.LE.0) RETURN - IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20 -* -* code for unequal increments or equal increments -* not equal to 1 -* - IX = 1 - IY = 1 - IF (INCX.LT.0) IX = (-N+1)*INCX + 1 - IF (INCY.LT.0) IY = (-N+1)*INCY + 1 - DO 10 I = 1,N - DTEMP = DTEMP + DX(IX)*DY(IY) - IX = IX + INCX - IY = IY + INCY - 10 CONTINUE - DDOT = DTEMP - RETURN + IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN * * code for both increments equal to 1 * * * clean-up loop * - 20 M = MOD(N,5) - IF (M.EQ.0) GO TO 40 - DO 30 I = 1,M - DTEMP = DTEMP + DX(I)*DY(I) - 30 CONTINUE - IF (N.LT.5) GO TO 60 - 40 MP1 = M + 1 - DO 50 I = MP1,N,5 + M = MOD(N,5) + IF (M.NE.0) THEN + DO I = 1,M + DTEMP = DTEMP + DX(I)*DY(I) + END DO + IF (N.LT.5) THEN + DDOT=DTEMP + RETURN + END IF + END IF + MP1 = M + 1 + DO I = MP1,N,5 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) - 50 CONTINUE - 60 DDOT = DTEMP + $ DX(I+2)*DY(I+2) + DX(I+3)*DY(I+3) + DX(I+4)*DY(I+4) + END DO + ELSE +* +* code for unequal increments or equal increments +* not equal to 1 +* + IX = 1 + IY = 1 + IF (INCX.LT.0) IX = (-N+1)*INCX + 1 + IF (INCY.LT.0) IY = (-N+1)*INCY + 1 + DO I = 1,N + DTEMP = DTEMP + DX(IX)*DY(IY) + IX = IX + INCX + IY = IY + INCY + END DO + END IF + DDOT = DTEMP RETURN END |