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Do not delete constants that input to exressions.

This commit is contained in:
steve 2000-01-02 17:56:42 +00:00
parent 645c24289e
commit c7193fa6fe
1 changed files with 36 additions and 14 deletions
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50
cprop.cc
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: cprop.cc,v 1.5 1999/12/30 04:19:12 steve Exp $"
#ident "$Id: cprop.cc,v 1.6 2000/01/02 17:56:42 steve Exp $"
#endif
# include "netlist.h"
@ -275,27 +275,46 @@ struct cprop_dc_functor : public functor_t {
void cprop_dc_functor::lpm_const(Design*des, NetConst*obj)
{
// If there are any links that take input, abort this
// operation.
// If there are any links that take input, the constant is
// used structurally somewhere.
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1)
if (count_inputs(obj->pin(idx)) > 0)
return;
// Look for signals that have NetESignal nodes attached to
// them. If I find any, this this constant is used by a
// behavioral expression somewhere.
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1) {
NetObj*cur;
unsigned pin;
obj->pin(idx).next_link(cur, pin);
while (cur != obj) {
NetNet*tmp = dynamic_cast<NetNet*>(cur);
if (tmp && tmp->get_eref() > 0)
return;
cur->pin(pin).next_link(cur, pin);
}
}
// If there are no other drivers, delete all the signals that
// are also dangling.
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1)
if (count_outputs(obj->pin(idx)) == 1) {
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1) {
if (count_outputs(obj->pin(idx)) != 1)
continue;
NetObj*cur;
unsigned pin;
obj->pin(idx).next_link(cur, pin);
while (cur != obj) {
cerr << "cprop: delete dangling signal " <<
cur->name() << "." << endl;
delete cur;
obj->pin(idx).next_link(cur, pin);
}
NetObj*cur;
unsigned pin;
obj->pin(idx).next_link(cur, pin);
while (cur != obj) {
NetNet*tmp = dynamic_cast<NetNet*>(cur);
cur->pin(pin).next_link(cur, pin);
assert(tmp->get_eref() == 0);
cerr << "cprop: delete dangling signal " <<
tmp->name() << "." << endl;
delete tmp;
}
}
// Done. Delete me.
delete obj;
@ -318,6 +337,9 @@ void cprop(Design*des)
/*
* $Log: cprop.cc,v $
* Revision 1.6 2000/01/02 17:56:42 steve
* Do not delete constants that input to exressions.
*
* Revision 1.5 1999/12/30 04:19:12 steve
* Propogate constant 0 in low bits of adders.
*