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 1.
28: *> \endverbatim
29: *
30: * Arguments:
31: * ==========
32: *
33: *> \param[in] N
34: *> \verbatim
35: *> N is INTEGER
36: *> number of elements in input vector(s)
37: *> \endverbatim
38: *>
39: *> \param[in] DX
40: *> \verbatim
41: *> DX is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
42: *> \endverbatim
43: *>
44: *> \param[in] INCX
45: *> \verbatim
46: *> INCX is INTEGER
47: *> storage spacing between elements of DX
48: *> \endverbatim
49: *>
50: *> \param[out] DY
51: *> \verbatim
52: *> DY is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
53: *> \endverbatim
54: *>
55: *> \param[in] INCY
56: *> \verbatim
57: *> INCY is INTEGER
58: *> storage spacing between elements of DY
59: *> \endverbatim
60: *
61: * Authors:
62: * ========
63: *
64: *> \author Univ. of Tennessee
65: *> \author Univ. of California Berkeley
66: *> \author Univ. of Colorado Denver
67: *> \author NAG Ltd.
68: *
69: *> \date November 2017
70: *
71: *> \ingroup double_blas_level1
72: *
73: *> \par Further Details:
74: * =====================
75: *>
76: *> \verbatim
77: *>
78: *> jack dongarra, linpack, 3/11/78.
79: *> modified 12/3/93, array(1) declarations changed to array(*)
80: *> \endverbatim
81: *>
82: * =====================================================================
83: SUBROUTINE DCOPY(N,DX,INCX,DY,INCY)
84: *
85: * -- Reference BLAS level1 routine (version 3.8.0) --
86: * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
87: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
88: * November 2017
89: *
90: * .. Scalar Arguments ..
91: INTEGER INCX,INCY,N
92: * ..
93: * .. Array Arguments ..
94: DOUBLE PRECISION DX(*),DY(*)
95: * ..
96: *
97: * =====================================================================
98: *
99: * .. Local Scalars ..
100: INTEGER I,IX,IY,M,MP1
101: * ..
102: * .. Intrinsic Functions ..
103: INTRINSIC MOD
104: * ..
105: IF (N.LE.0) RETURN
106: IF (INCX.EQ.1 .AND. INCY.EQ.1) THEN
107: *
108: * code for both increments equal to 1
109: *
110: *
111: * clean-up loop
112: *
113: M = MOD(N,7)
114: IF (M.NE.0) THEN
115: DO I = 1,M
116: DY(I) = DX(I)
117: END DO
118: IF (N.LT.7) RETURN
119: END IF
120: MP1 = M + 1
121: DO I = MP1,N,7
122: DY(I) = DX(I)
123: DY(I+1) = DX(I+1)
124: DY(I+2) = DX(I+2)
125: DY(I+3) = DX(I+3)
126: DY(I+4) = DX(I+4)
127: DY(I+5) = DX(I+5)
128: DY(I+6) = DX(I+6)
129: END DO
130: ELSE
131: *
132: * code for unequal increments or equal increments
133: * not equal to 1
134: *
135: IX = 1
136: IY = 1
137: IF (INCX.LT.0) IX = (-N+1)*INCX + 1
138: IF (INCY.LT.0) IY = (-N+1)*INCY + 1
139: DO I = 1,N
140: DY(IY) = DX(IX)
141: IX = IX + INCX
142: IY = IY + INCY
143: END DO
144: END IF
145: RETURN
146: END
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