opencv/3rdparty/lapack/slaswp.c

146 lines
3.4 KiB
C

#include "clapack.h"
/* Subroutine */ int slaswp_(integer *n, real *a, integer *lda, integer *k1,
integer *k2, integer *ipiv, integer *incx)
{
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
/* Local variables */
integer i__, j, k, i1, i2, n32, ip, ix, ix0, inc;
real temp;
/* -- LAPACK auxiliary routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLASWP performs a series of row interchanges on the matrix A. */
/* One row interchange is initiated for each of rows K1 through K2 of A. */
/* Arguments */
/* ========= */
/* N (input) INTEGER */
/* The number of columns of the matrix A. */
/* A (input/output) REAL array, dimension (LDA,N) */
/* On entry, the matrix of column dimension N to which the row */
/* interchanges will be applied. */
/* On exit, the permuted matrix. */
/* LDA (input) INTEGER */
/* The leading dimension of the array A. */
/* K1 (input) INTEGER */
/* The first element of IPIV for which a row interchange will */
/* be done. */
/* K2 (input) INTEGER */
/* The last element of IPIV for which a row interchange will */
/* be done. */
/* IPIV (input) INTEGER array, dimension (K2*abs(INCX)) */
/* The vector of pivot indices. Only the elements in positions */
/* K1 through K2 of IPIV are accessed. */
/* IPIV(K) = L implies rows K and L are to be interchanged. */
/* INCX (input) INTEGER */
/* The increment between successive values of IPIV. If IPIV */
/* is negative, the pivots are applied in reverse order. */
/* Further Details */
/* =============== */
/* Modified by */
/* R. C. Whaley, Computer Science Dept., Univ. of Tenn., Knoxville, USA */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
/* Interchange row I with row IPIV(I) for each of rows K1 through K2. */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
--ipiv;
/* Function Body */
if (*incx > 0) {
ix0 = *k1;
i1 = *k1;
i2 = *k2;
inc = 1;
} else if (*incx < 0) {
ix0 = (1 - *k2) * *incx + 1;
i1 = *k2;
i2 = *k1;
inc = -1;
} else {
return 0;
}
n32 = *n / 32 << 5;
if (n32 != 0) {
i__1 = n32;
for (j = 1; j <= i__1; j += 32) {
ix = ix0;
i__2 = i2;
i__3 = inc;
for (i__ = i1; i__3 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__3)
{
ip = ipiv[ix];
if (ip != i__) {
i__4 = j + 31;
for (k = j; k <= i__4; ++k) {
temp = a[i__ + k * a_dim1];
a[i__ + k * a_dim1] = a[ip + k * a_dim1];
a[ip + k * a_dim1] = temp;
/* L10: */
}
}
ix += *incx;
/* L20: */
}
/* L30: */
}
}
if (n32 != *n) {
++n32;
ix = ix0;
i__1 = i2;
i__3 = inc;
for (i__ = i1; i__3 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__3) {
ip = ipiv[ix];
if (ip != i__) {
i__2 = *n;
for (k = n32; k <= i__2; ++k) {
temp = a[i__ + k * a_dim1];
a[i__ + k * a_dim1] = a[ip + k * a_dim1];
a[ip + k * a_dim1] = temp;
/* L40: */
}
}
ix += *incx;
/* L50: */
}
}
return 0;
/* End of SLASWP */
} /* slaswp_ */