Annotation of rpl/lapack/blas/dcopy.f, revision 1.11
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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