1HPL_daxpy(3) HPL Library Functions HPL_daxpy(3)
2
3
4
6 HPL_daxpy - y := y + alpha * x.
7
9 #include "hpl.h"
10
11 void HPL_daxpy( const int N, const double ALPHA, const double * X,
12 const int INCX, double * Y, const int INCY );
13
15 HPL_daxpy scales the vector x by alpha and adds it to y.
16
18 N (local input) const int
19 On entry, N specifies the length of the vectors x and y. N
20 must be at least zero.
21
22 ALPHA (local input) const double
23 On entry, ALPHA specifies the scalar alpha. When ALPHA is
24 supplied as zero, then the entries of the incremented array X
25 need not be set on input.
26
27 X (local input) const double *
28 On entry, X is an incremented array of dimension at least (
29 1 + ( n - 1 ) * abs( INCX ) ) that contains the vector x.
30
31 INCX (local input) const int
32 On entry, INCX specifies the increment for the elements of X.
33 INCX must not be zero.
34
35 Y (local input/output) double *
36 On entry, Y is an incremented array of dimension at least (
37 1 + ( n - 1 ) * abs( INCY ) ) that contains the vector y. On
38 exit, the entries of the incremented array Y are updated with
39 the scaled entries of the incremented array X.
40
41 INCY (local input) const int
42 On entry, INCY specifies the increment for the elements of Y.
43 INCY must not be zero.
44
46 #include "hpl.h"
47
48 int main(int argc, char *argv[])
49 {
50 double x[3], y[3];
51 x[0] = 1.0; x[1] = 2.0; x[2] = 3.0;
52 y[0] = 4.0; y[1] = 5.0; y[2] = 6.0;
53 HPL_daxpy( 3, 2.0, x, 1, y, 1 );
54 printf("y=[%f,%f,%f]\n", y[0], y[1], y[2]);
55 exit(0); return(0);
56 }
57
59 HPL_dcopy (3), HPL_dscal (3), HPL_dswap (3).
60
61
62
63HPL 2.1 October 26, 2012 HPL_daxpy(3)