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Propagate initial value of constants into wires.

This commit is contained in:
steve 2000-12-30 03:11:15 +00:00
parent e68c26bb87
commit 365b149ec1
1 changed files with 26 additions and 1 deletions
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27
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) && !defined(macintosh)
#ident "$Id: cprop.cc,v 1.22 2000/11/23 01:55:52 steve Exp $"
#ident "$Id: cprop.cc,v 1.23 2000/12/30 03:11:15 steve Exp $"
#endif
# include "netlist.h"
@ -742,6 +742,28 @@ void cprop_dc_functor::lpm_const(Design*des, NetConst*obj)
}
}
// For each bit, if this is the only driver, then set the
// initial value of all the signals to this value.
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1) {
if (count_outputs(obj->pin(idx)) > 1)
continue;
Nexus*nex = obj->pin(idx).nexus();
for (Link*clnk = nex->first_nlink()
; clnk ; clnk = clnk->next_nlink()) {
NetObj*cur;
unsigned pin;
clnk->cur_link(cur, pin);
NetNet*tmp = dynamic_cast<NetNet*>(cur);
if (tmp == 0)
continue;
tmp->pin(pin).set_init(obj->value(idx));
}
}
// If there are any links that take input, the constant is
// used structurally somewhere.
for (unsigned idx = 0 ; idx < obj->pin_count() ; idx += 1)
@ -789,6 +811,9 @@ void cprop(Design*des)
/*
* $Log: cprop.cc,v $
* Revision 1.23 2000/12/30 03:11:15 steve
* Propagate initial value of constants into wires.
*
* Revision 1.22 2000/11/23 01:55:52 steve
* Propagate constants through xnor gates. (PR#51)
*