Annotation of rpl/lapack/blas/dcopy.f, revision 1.8
1.8 ! bertrand 1: *> \brief \b DCOPY
! 2: *
! 3: * =========== DOCUMENTATION ===========
! 4: *
! 5: * Online html documentation available at
! 6: * http://www.netlib.org/lapack/explore-html/
! 7: *
! 8: * Definition:
! 9: * ===========
! 10: *
! 11: * SUBROUTINE DCOPY(N,DX,INCX,DY,INCY)
! 12: *
! 13: * .. Scalar Arguments ..
! 14: * INTEGER INCX,INCY,N
! 15: * ..
! 16: * .. Array Arguments ..
! 17: * DOUBLE PRECISION DX(*),DY(*)
! 18: * ..
! 19: *
! 20: *
! 21: *> \par Purpose:
! 22: * =============
! 23: *>
! 24: *> \verbatim
! 25: *>
! 26: *> DCOPY copies a vector, x, to a vector, y.
! 27: *> uses unrolled loops for increments equal to one.
! 28: *> \endverbatim
! 29: *
! 30: * Authors:
! 31: * ========
! 32: *
! 33: *> \author Univ. of Tennessee
! 34: *> \author Univ. of California Berkeley
! 35: *> \author Univ. of Colorado Denver
! 36: *> \author NAG Ltd.
! 37: *
! 38: *> \date November 2011
! 39: *
! 40: *> \ingroup double_blas_level1
! 41: *
! 42: *> \par Further Details:
! 43: * =====================
! 44: *>
! 45: *> \verbatim
! 46: *>
! 47: *> jack dongarra, linpack, 3/11/78.
! 48: *> modified 12/3/93, array(1) declarations changed to array(*)
! 49: *> \endverbatim
! 50: *>
! 51: * =====================================================================
1.1 bertrand 52: SUBROUTINE DCOPY(N,DX,INCX,DY,INCY)
1.8 ! bertrand 53: *
! 54: * -- Reference BLAS level1 routine (version 3.4.0) --
! 55: * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
! 56: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
! 57: * November 2011
! 58: *
1.1 bertrand 59: * .. Scalar Arguments ..
60: INTEGER INCX,INCY,N
61: * ..
62: * .. Array Arguments ..
63: DOUBLE PRECISION DX(*),DY(*)
64: * ..
65: *
66: * =====================================================================
67: *
68: * .. Local Scalars ..
69: INTEGER I,IX,IY,M,MP1
70: * ..
71: * .. Intrinsic Functions ..
72: INTRINSIC MOD
73: * ..
74: IF (N.LE.0) RETURN
1.7 bertrand 75: IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
1.1 bertrand 76: *
1.7 bertrand 77: * code for both increments equal to 1
1.1 bertrand 78: *
79: *
1.7 bertrand 80: * clean-up loop
1.1 bertrand 81: *
1.7 bertrand 82: M = MOD(N,7)
83: IF (M.NE.0) THEN
84: DO I = 1,M
85: DY(I) = DX(I)
86: END DO
87: IF (N.LT.7) RETURN
88: END IF
89: MP1 = M + 1
90: DO I = MP1,N,7
91: DY(I) = DX(I)
92: DY(I+1) = DX(I+1)
93: DY(I+2) = DX(I+2)
94: DY(I+3) = DX(I+3)
95: DY(I+4) = DX(I+4)
96: DY(I+5) = DX(I+5)
97: DY(I+6) = DX(I+6)
98: END DO
99: ELSE
1.1 bertrand 100: *
1.7 bertrand 101: * code for unequal increments or equal increments
102: * not equal to 1
1.1 bertrand 103: *
1.7 bertrand 104: IX = 1
105: IY = 1
106: IF (INCX.LT.0) IX = (-N+1)*INCX + 1
107: IF (INCY.LT.0) IY = (-N+1)*INCY + 1
108: DO I = 1,N
109: DY(IY) = DX(IX)
110: IX = IX + INCX
111: IY = IY + INCY
112: END DO
113: END IF
1.1 bertrand 114: RETURN
115: END
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