LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
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dcopy.f
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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*> \ingroup copy
70*
71*> \par Further Details:
72* =====================
73*>
74*> \verbatim
75*>
76*> jack dongarra, linpack, 3/11/78.
77*> modified 12/3/93, array(1) declarations changed to array(*)
78*> \endverbatim
79*>
80* =====================================================================
81 SUBROUTINE dcopy(N,DX,INCX,DY,INCY)
82*
83* -- Reference BLAS level1 routine --
84* -- Reference BLAS is a software package provided by Univ. of Tennessee, --
85* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
86*
87* .. Scalar Arguments ..
88 INTEGER INCX,INCY,N
89* ..
90* .. Array Arguments ..
91 DOUBLE PRECISION DX(*),DY(*)
92* ..
93*
94* =====================================================================
95*
96* .. Local Scalars ..
97 INTEGER I,IX,IY,M,MP1
98* ..
99* .. Intrinsic Functions ..
100 INTRINSIC mod
101* ..
102 IF (n.LE.0) RETURN
103 IF (incx.EQ.1 .AND. incy.EQ.1) THEN
104*
105* code for both increments equal to 1
106*
107*
108* clean-up loop
109*
110 m = mod(n,7)
111 IF (m.NE.0) THEN
112 DO i = 1,m
113 dy(i) = dx(i)
114 END DO
115 IF (n.LT.7) RETURN
116 END IF
117 mp1 = m + 1
118 DO i = mp1,n,7
119 dy(i) = dx(i)
120 dy(i+1) = dx(i+1)
121 dy(i+2) = dx(i+2)
122 dy(i+3) = dx(i+3)
123 dy(i+4) = dx(i+4)
124 dy(i+5) = dx(i+5)
125 dy(i+6) = dx(i+6)
126 END DO
127 ELSE
128*
129* code for unequal increments or equal increments
130* not equal to 1
131*
132 ix = 1
133 iy = 1
134 IF (incx.LT.0) ix = (-n+1)*incx + 1
135 IF (incy.LT.0) iy = (-n+1)*incy + 1
136 DO i = 1,n
137 dy(iy) = dx(ix)
138 ix = ix + incx
139 iy = iy + incy
140 END DO
141 END IF
142 RETURN
143*
144* End of DCOPY
145*
146 END
subroutine dcopy(n, dx, incx, dy, incy)
DCOPY
Definition dcopy.f:82