LAPACK  3.4.1
LAPACK: Linear Algebra PACKage
scopy.f
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00001 *> \brief \b SCOPY
00002 *
00003 *  =========== DOCUMENTATION ===========
00004 *
00005 * Online html documentation available at 
00006 *            http://www.netlib.org/lapack/explore-html/ 
00007 *
00008 *  Definition:
00009 *  ===========
00010 *
00011 *       SUBROUTINE SCOPY(N,SX,INCX,SY,INCY)
00012 * 
00013 *       .. Scalar Arguments ..
00014 *       INTEGER INCX,INCY,N
00015 *       ..
00016 *       .. Array Arguments ..
00017 *       REAL SX(*),SY(*)
00018 *       ..
00019 *  
00020 *
00021 *> \par Purpose:
00022 *  =============
00023 *>
00024 *> \verbatim
00025 *>
00026 *>    SCOPY copies a vector, x, to a vector, y.
00027 *>    uses unrolled loops for increments equal to 1.
00028 *> \endverbatim
00029 *
00030 *  Authors:
00031 *  ========
00032 *
00033 *> \author Univ. of Tennessee 
00034 *> \author Univ. of California Berkeley 
00035 *> \author Univ. of Colorado Denver 
00036 *> \author NAG Ltd. 
00037 *
00038 *> \date November 2011
00039 *
00040 *> \ingroup single_blas_level1
00041 *
00042 *> \par Further Details:
00043 *  =====================
00044 *>
00045 *> \verbatim
00046 *>
00047 *>     jack dongarra, linpack, 3/11/78.
00048 *>     modified 12/3/93, array(1) declarations changed to array(*)
00049 *> \endverbatim
00050 *>
00051 *  =====================================================================
00052       SUBROUTINE SCOPY(N,SX,INCX,SY,INCY)
00053 *
00054 *  -- Reference BLAS level1 routine (version 3.4.0) --
00055 *  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
00056 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00057 *     November 2011
00058 *
00059 *     .. Scalar Arguments ..
00060       INTEGER INCX,INCY,N
00061 *     ..
00062 *     .. Array Arguments ..
00063       REAL SX(*),SY(*)
00064 *     ..
00065 *
00066 *  =====================================================================
00067 *
00068 *     .. Local Scalars ..
00069       INTEGER I,IX,IY,M,MP1
00070 *     ..
00071 *     .. Intrinsic Functions ..
00072       INTRINSIC MOD
00073 *     ..
00074       IF (N.LE.0) RETURN
00075       IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
00076 *
00077 *        code for both increments equal to 1
00078 *
00079 *
00080 *        clean-up loop
00081 *
00082          M = MOD(N,7)
00083          IF (M.NE.0) THEN
00084             DO I = 1,M
00085                SY(I) = SX(I)
00086             END DO
00087             IF (N.LT.7) RETURN
00088          END IF   
00089          MP1 = M + 1
00090          DO I = MP1,N,7
00091             SY(I) = SX(I)
00092             SY(I+1) = SX(I+1)
00093             SY(I+2) = SX(I+2)
00094             SY(I+3) = SX(I+3)
00095             SY(I+4) = SX(I+4)
00096             SY(I+5) = SX(I+5)
00097             SY(I+6) = SX(I+6)
00098          END DO
00099       ELSE      
00100 *
00101 *        code for unequal increments or equal increments
00102 *          not equal to 1
00103 *
00104          IX = 1
00105          IY = 1
00106          IF (INCX.LT.0) IX = (-N+1)*INCX + 1
00107          IF (INCY.LT.0) IY = (-N+1)*INCY + 1
00108          DO I = 1,N
00109             SY(IY) = SX(IX)
00110             IX = IX + INCX
00111             IY = IY + INCY
00112          END DO
00113       END IF
00114       RETURN
00115       END
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