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Diffstat (limited to 'intern/opennl/superlu/heap_relax_snode.c')
| -rw-r--r-- | intern/opennl/superlu/heap_relax_snode.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/intern/opennl/superlu/heap_relax_snode.c b/intern/opennl/superlu/heap_relax_snode.c new file mode 100644 index 00000000000..86971f59571 --- /dev/null +++ b/intern/opennl/superlu/heap_relax_snode.c @@ -0,0 +1,116 @@ +/* + * -- SuperLU routine (version 3.0) -- + * Univ. of California Berkeley, Xerox Palo Alto Research Center, + * and Lawrence Berkeley National Lab. + * October 15, 2003 + * + */ +/* + 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" + +void +heap_relax_snode ( + const int n, + int *et, /* column elimination tree */ + const int relax_columns, /* max no of columns allowed in a + relaxed snode */ + int *descendants, /* no of descendants of each node + in the etree */ + int *relax_end /* last column in a supernode */ + ) +{ +/* + * Purpose + * ======= + * relax_snode() - Identify the initial relaxed supernodes, assuming that + * the matrix has been reordered according to the postorder of the etree. + * + */ + register int i, j, k, l, parent; + register int snode_start; /* beginning of a snode */ + int *et_save, *post, *inv_post, *iwork; + int nsuper_et = 0, nsuper_et_post = 0; + + /* The etree may not be postordered, but is heap ordered. */ + + iwork = (int*) intMalloc(3*n+2); + if ( !iwork ) ABORT("SUPERLU_MALLOC fails for iwork[]"); + inv_post = iwork + n+1; + et_save = inv_post + n+1; + + /* Post order etree */ + post = (int *) TreePostorder(n, et); + for (i = 0; i < n+1; ++i) inv_post[post[i]] = i; + + /* Renumber etree in postorder */ + for (i = 0; i < n; ++i) { + iwork[post[i]] = post[et[i]]; + et_save[i] = et[i]; /* Save the original etree */ + } + for (i = 0; i < n; ++i) et[i] = iwork[i]; + + /* Compute the number of descendants of each node in the etree */ + ifill (relax_end, n, EMPTY); + for (j = 0; j < n; j++) descendants[j] = 0; + for (j = 0; j < n; j++) { + parent = et[j]; + if ( parent != n ) /* not the dummy root */ + descendants[parent] += descendants[j] + 1; + } + + /* Identify the relaxed supernodes by postorder traversal of the etree. */ + for (j = 0; j < n; ) { + parent = et[j]; + snode_start = j; + while ( parent != n && descendants[parent] < relax_columns ) { + j = parent; + parent = et[j]; + } + /* Found a supernode in postordered etree; j is the last column. */ + ++nsuper_et_post; + k = n; + for (i = snode_start; i <= j; ++i) + k = SUPERLU_MIN(k, inv_post[i]); + l = inv_post[j]; + if ( (l - k) == (j - snode_start) ) { + /* It's also a supernode in the original etree */ + relax_end[k] = l; /* Last column is recorded */ + ++nsuper_et; + } else { + for (i = snode_start; i <= j; ++i) { + l = inv_post[i]; + if ( descendants[i] == 0 ) relax_end[l] = l; + } + } + j++; + /* Search for a new leaf */ + while ( descendants[j] != 0 && j < n ) j++; + } + +#if ( PRNTlevel>=1 ) + printf(".. heap_snode_relax:\n" + "\tNo of relaxed snodes in postordered etree:\t%d\n" + "\tNo of relaxed snodes in original etree:\t%d\n", + nsuper_et_post, nsuper_et); +#endif + + /* Recover the original etree */ + for (i = 0; i < n; ++i) et[i] = et_save[i]; + + SUPERLU_FREE(post); + SUPERLU_FREE(iwork); +} + + |