1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
/** \file opennl/superlu/spruneL.c
* \ingroup opennl
*/
/*
* -- SuperLU routine (version 2.0) --
* Univ. of California Berkeley, Xerox Palo Alto Research Center,
* and Lawrence Berkeley National Lab.
* November 15, 1997
*
*/
/*
Copyright (c) 1994 by Xerox Corporation. All rights reserved.
THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
Permission is hereby granted to use or copy this program for any
purpose, provided the above notices are retained on all copies.
Permission to modify the code and to distribute modified code is
granted, provided the above notices are retained, and a notice that
the code was modified is included with the above copyright notice.
*/
#include "ssp_defs.h"
#include "util.h"
void
spruneL(
const int jcol, /* in */
const int *perm_r, /* in */
const int pivrow, /* in */
const int nseg, /* in */
const int *segrep, /* in */
const int *repfnz, /* in */
int *xprune, /* out */
GlobalLU_t *Glu /* modified - global LU data structures */
)
{
/*
* Purpose
* =======
* Prunes the L-structure of supernodes whose L-structure
* contains the current pivot row "pivrow"
*
*/
double utemp;
int jsupno, irep, irep1, kmin, kmax, krow, movnum;
int i, ktemp, minloc, maxloc;
int do_prune; /* logical variable */
int *xsup, *supno;
int *lsub, *xlsub;
double *lusup;
int *xlusup;
xsup = Glu->xsup;
supno = Glu->supno;
lsub = Glu->lsub;
xlsub = Glu->xlsub;
lusup = Glu->lusup;
xlusup = Glu->xlusup;
/*
* For each supernode-rep irep in U[*,j]
*/
jsupno = supno[jcol];
for (i = 0; i < nseg; i++) {
irep = segrep[i];
irep1 = irep + 1;
do_prune = FALSE;
/* Don't prune with a zero U-segment */
if ( repfnz[irep] == EMPTY )
continue;
/* If a snode overlaps with the next panel, then the U-segment
* is fragmented into two parts -- irep and irep1. We should let
* pruning occur at the rep-column in irep1's snode.
*/
if ( supno[irep] == supno[irep1] ) /* Don't prune */
continue;
/*
* If it has not been pruned & it has a nonz in row L[pivrow,i]
*/
if ( supno[irep] != jsupno ) {
if ( xprune[irep] >= xlsub[irep1] ) {
kmin = xlsub[irep];
kmax = xlsub[irep1] - 1;
for (krow = kmin; krow <= kmax; krow++)
if ( lsub[krow] == pivrow ) {
do_prune = TRUE;
break;
}
}
if ( do_prune ) {
/* Do a quicksort-type partition
* movnum=TRUE means that the num values have to be exchanged.
*/
movnum = FALSE;
if ( irep == xsup[supno[irep]] ) /* Snode of size 1 */
movnum = TRUE;
while ( kmin <= kmax ) {
if ( perm_r[lsub[kmax]] == EMPTY )
kmax--;
else if ( perm_r[lsub[kmin]] != EMPTY )
kmin++;
else { /* kmin below pivrow, and kmax above pivrow:
* interchange the two subscripts
*/
ktemp = lsub[kmin];
lsub[kmin] = lsub[kmax];
lsub[kmax] = ktemp;
/* If the supernode has only one column, then we
* only keep one set of subscripts. For any subscript
* interchange performed, similar interchange must be
* done on the numerical values.
*/
if ( movnum ) {
minloc = xlusup[irep] + (kmin - xlsub[irep]);
maxloc = xlusup[irep] + (kmax - xlsub[irep]);
utemp = lusup[minloc];
lusup[minloc] = lusup[maxloc];
lusup[maxloc] = utemp;
}
kmin++;
kmax--;
}
} /* while */
xprune[irep] = kmin; /* Pruning */
#ifdef CHK_PRUNE
printf(" After spruneL(),using col %d: xprune[%d] = %d\n",
jcol, irep, kmin);
#endif
} /* if do_prune */
} /* if */
} /* for each U-segment... */
}
|
