/*
* Revision Control Information
*
* $Source$
* $Author$
* $Revision$
* $Date$
*
*/
#include "espresso.h"
ABC_NAMESPACE_IMPL_START
/*
The cofactor of a cover against a cube "c" is a cover formed by the
cofactor of each cube in the cover against c. The cofactor of two
cubes is null if they are distance 1 or more apart. If they are
distance zero apart, the cofactor is the restriction of the cube
to the minterms of c.
The cube list contains the following information:
T[0] = pointer to a cube identifying the variables that have
been cofactored against
T[1] = pointer to just beyond the sentinel (i.e., T[n] in this case)
T[2]
.
. = pointers to cubes
.
T[n-2]
T[n-1] = NULL pointer (sentinel)
Cofactoring involves repeated application of "cdist0" to check if a
cube of the cover intersects the cofactored cube. This can be
slow, especially for the recursive descent of the espresso
routines. Therefore, a special cofactor routine "scofactor" is
provided which assumes the cofactor is only in a single variable.
*/
/* cofactor -- compute the cofactor of a cover with respect to a cube */
pcube *cofactor(T, c)
IN pcube *T;
IN register pcube c;
{
pcube temp = cube.temp[0], *Tc_save, *Tc, *T1;
register pcube p;
int listlen;
listlen = CUBELISTSIZE(T) + 5;
/* Allocate a new list of cube pointers (max size is previous size) */
Tc_save = Tc = ALLOC(pcube, listlen);
/* pass on which variables have been cofactored against */
*Tc++ = set_or(new_cube(), T[0], set_diff(temp, cube.fullset, c));
Tc++;
/* Loop for each cube in the list, determine suitability, and save */
for(T1 = T+2; (p = *T1++) != NULL; ) {
if (p != c) {
#ifdef NO_INLINE
if (! cdist0(p, c)) goto false;
#else
{register int w,last;register unsigned int x;if((last=cube.inword)!=-1)
{x=p[last]&c[last];if(~(x|x>>1)&cube.inmask)goto false;for(w=1;w<last;w++)
{x=p[w]&c[w];if(~(x|x>>1)&DISJOINT)goto false;}}}{register int w,var,last;
register pcube mask;for(var=cube.num_binary_vars;var<cube.num_vars;var++){
mask=cube.var_mask[var];last=cube.last_word[var];for(w=cube.first_word[var
];w<=last;w++)if(p[w]&c[w]&mask[w])goto nextvar;goto false;nextvar:;}}
#endif
*Tc++ = p;
false: ;
}
}
*Tc++ = (pcube) NULL; /* sentinel */
Tc_save[1] = (pcube) Tc; /* save pointer to last */
return Tc_save;
}
/*
scofactor -- compute the cofactor of a cover with respect to a cube,
where the cube is "active" in only a single variable.
This routine has been optimized for speed.
*/
pcube *scofactor(T, c, var)
IN pcube *T, c;
IN int var;
{
pcube *Tc, *Tc_save;
register pcube p, mask = cube.temp[1], *T1;
register int first = cube.first_word[var], last = cube.last_word[var];
int listlen;
listlen = CUBELISTSIZE(T) + 5;
/* Allocate a new list of cube pointers (max size is previous size) */
Tc_save = Tc = ALLOC(pcube, listlen);
/* pass on which variables have been cofactored against */
*Tc++ = set_or(new_cube(), T[0], set_diff(mask, cube.fullset, c));
Tc++;
/* Setup for the quick distance check */
(void) set_and(mask, cube.var_mask[var], c);
/* Loop for each cube in the list, determine suitability, and save */
for(T1 = T+2; (p = *T1++) != NULL; )
if (p != c) {
register int i = first;
do
if (p[i] & mask[i]) {
*Tc++ = p;
break;
}
while (++i <= last);
}
*Tc++ = (pcube) NULL; /* sentinel */
Tc_save[1] = (pcube) Tc; /* save pointer to last */
return Tc_save;
}
void massive_count(T)
IN pcube *T;
{
int *count = cdata.part_zeros;
pcube *T1;
/* Clear the column counts (count of # zeros in each column) */
{ register int i;
for(i = cube.size - 1; i >= 0; i--)
count[i] = 0;
}
/* Count the number of zeros in each column */
{ register int i, *cnt;
register unsigned int val;
register pcube p, cof = T[0], full = cube.fullset;
for(T1 = T+2; (p = *T1++) != NULL; )
for(i = LOOP(p); i > 0; i--)
if ((val = full[i] & ~ (p[i] | cof[i]))) {
cnt = count + ((i-1) << LOGBPI);
#if BPI == 32
if (val & 0xFF000000) {
if (val & 0x80000000) cnt[31]++;
if (val & 0x40000000) cnt[30]++;
if (val & 0x20000000) cnt[29]++;
if (val & 0x10000000) cnt[28]++;
if (val & 0x08000000) cnt[27]++;
if (val & 0x04000000) cnt[26]++;
if (val & 0x02000000) cnt[25]++;
if (val & 0x01000000) cnt[24]++;
}
if (val & 0x00FF0000) {
if (val & 0x00800000) cnt[23]++;
if (val & 0x00400000) cnt[22]++;
if (val & 0x00200000) cnt[21]++;
if (val & 0x00100000) cnt[20]++;
if (val & 0x00080000) cnt[19]++;
if (val & 0x00040000) cnt[18]++;
if (val & 0x00020000) cnt[17]++;
if (val & 0x00010000) cnt[16]++;
}
#endif
if (val & 0xFF00) {
if (val & 0x8000) cnt[15]++;
if (val & 0x4000) cnt[14]++;
if (val & 0x2000) cnt[13]++;
if (val & 0x1000) cnt[12]++;
if (val & 0x0800) cnt[11]++;
if (val & 0x0400) cnt[10]++;
if (val & 0x0200) cnt[ 9]++;
if (val & 0x0100) cnt[ 8]++;
}
if (val & 0x00FF) {
if (val & 0x0080) cnt[ 7]++;
if (val & 0x0040) cnt[ 6]++;
if (val & 0x0020) cnt[ 5]++;
if (val & 0x0010) cnt[ 4]++;
if (val & 0x0008) cnt[ 3]++;
if (val & 0x0004) cnt[ 2]++;
if (val & 0x0002) cnt[ 1]++;
if (val & 0x0001) cnt[ 0]++;
}
}
}
/*
* Perform counts for each variable:
* cdata.var_zeros[var] = number of zeros in the variable
* cdata.parts_active[var] = number of active parts for each variable
* cdata.vars_active = number of variables which are active
* cdata.vars_unate = number of variables which are active and unate
*
* best -- the variable which is best for splitting based on:
* mostactive -- most # active parts in any variable
* mostzero -- most # zeros in any variable
* mostbalanced -- minimum over the maximum # zeros / part / variable
*/
{ register int var, i, lastbit, active, maxactive;
int best = -1, mostactive = 0, mostzero = 0, mostbalanced = 32000;
cdata.vars_unate = cdata.vars_active = 0;
for(var = 0; var < cube.num_vars; var++) {
if (var < cube.num_binary_vars) { /* special hack for binary vars */
i = count[var*2];
lastbit = count[var*2 + 1];
active = (i > 0) + (lastbit > 0);
cdata.var_zeros[var] = i + lastbit;
maxactive = MAX(i, lastbit);
} else {
maxactive = active = cdata.var_zeros[var] = 0;
lastbit = cube.last_part[var];
for(i = cube.first_part[var]; i <= lastbit; i++) {
cdata.var_zeros[var] += count[i];
active += (count[i] > 0);
if (active > maxactive) maxactive = active;
}
}
/* first priority is to maximize the number of active parts */
/* for binary case, this will usually select the output first */
if (active > mostactive)
best = var, mostactive = active, mostzero = cdata.var_zeros[best],
mostbalanced = maxactive;
else if (active == mostactive)
{
/* secondary condition is to maximize the number zeros */
/* for binary variables, this is the same as minimum # of 2's */
if (cdata.var_zeros[var] > mostzero)
best = var, mostzero = cdata.var_zeros[best],
mostbalanced = maxactive;
else if (cdata.var_zeros[var] == mostzero)
/* third condition is to pick a balanced variable */
/* for binary vars, this means roughly equal # 0's and 1's */
if (maxactive < mostbalanced)
best = var, mostbalanced = maxactive;
}
cdata.parts_active[var] = active;
cdata.is_unate[var] = (active == 1);
cdata.vars_active += (active > 0);
cdata.vars_unate += (active == 1);
}
cdata.best = best;
}
}
int binate_split_select(T, cleft, cright, debug_flag)
IN pcube *T;
IN register pcube cleft, cright;
IN int debug_flag;
{
int best = cdata.best;
register int i, lastbit = cube.last_part[best], halfbit = 0;
register pcube cof=T[0];
/* Create the cubes to cofactor against */
(void) set_diff(cleft, cube.fullset, cube.var_mask[best]);
(void) set_diff(cright, cube.fullset, cube.var_mask[best]);
for(i = cube.first_part[best]; i <= lastbit; i++)
if (! is_in_set(cof,i))
halfbit++;
for(i = cube.first_part[best], halfbit = halfbit/2; halfbit > 0; i++)
if (! is_in_set(cof,i))
halfbit--, set_insert(cleft, i);
for(; i <= lastbit; i++)
if (! is_in_set(cof,i))
set_insert(cright, i);
if (debug & debug_flag) {
(void) printf("BINATE_SPLIT_SELECT: split against %d\n", best);
if (verbose_debug)
(void) printf("cl=%s\ncr=%s\n", pc1(cleft), pc2(cright));
}
return best;
}
pcube *cube1list(A)
pcover A;
{
register pcube last, p, *plist, *list;
list = plist = ALLOC(pcube, A->count + 3);
*plist++ = new_cube();
plist++;
foreach_set(A, last, p) {
*plist++ = p;
}
*plist++ = NULL; /* sentinel */
list[1] = (pcube) plist;
return list;
}
pcube *cube2list(A, B)
pcover A, B;
{
register pcube last, p, *plist, *list;
list = plist = ALLOC(pcube, A->count + B->count + 3);
*plist++ = new_cube();
plist++;
foreach_set(A, last, p) {
*plist++ = p;
}
foreach_set(B, last, p) {
*plist++ = p;
}
*plist++ = NULL;
list[1] = (pcube) plist;
return list;
}
pcube *cube3list(A, B, C)
pcover A, B, C;
{
register pcube last, p, *plist, *list;
plist = ALLOC(pcube, A->count + B->count + C->count + 3);
list = plist;
*plist++ = new_cube();
plist++;
foreach_set(A, last, p) {
*plist++ = p;
}
foreach_set(B, last, p) {
*plist++ = p;
}
foreach_set(C, last, p) {
*plist++ = p;
}
*plist++ = NULL;
list[1] = (pcube) plist;
return list;
}
pcover cubeunlist(A1)
pcube *A1;
{
register int i;
register pcube p, pdest, cof = A1[0];
register pcover A;
A = new_cover(CUBELISTSIZE(A1));
for(i = 2; (p = A1[i]) != NULL; i++) {
pdest = GETSET(A, i-2);
INLINEset_or(pdest, p, cof);
}
A->count = CUBELISTSIZE(A1);
return A;
}
void simplify_cubelist(T)
pcube *T;
{
register pcube *Tdest;
register int i, ncubes;
(void) set_copy(cube.temp[0], T[0]); /* retrieve cofactor */
ncubes = CUBELISTSIZE(T);
qsort((char *) (T+2), ncubes, sizeof(pset), (int (*)()) d1_order);
Tdest = T+2;
/* *Tdest++ = T[2]; */
for(i = 3; i < ncubes; i++) {
if (d1_order(&T[i-1], &T[i]) != 0) {
*Tdest++ = T[i];
}
}
*Tdest++ = NULL; /* sentinel */
Tdest[1] = (pcube) Tdest; /* save pointer to last */
}
ABC_NAMESPACE_IMPL_END