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Evaluate constant logical && and ||.

This commit is contained in:
steve 2001-01-04 04:28:42 +00:00
parent ac7ae1ba6f
commit d5ec89813d
1 changed files with 65 additions and 2 deletions
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67
eval_tree.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: eval_tree.cc,v 1.18 2001/01/02 04:21:14 steve Exp $"
#ident "$Id: eval_tree.cc,v 1.19 2001/01/04 04:28:42 steve Exp $"
#endif
# include "netlist.h"
@ -318,7 +318,67 @@ NetEConst* NetEBDiv::eval_tree()
NetEConst* NetEBLogic::eval_tree()
{
eval_sub_tree_();
return 0;
NetEConst*lc = dynamic_cast<NetEConst*>(left_);
if (lc == 0) return 0;
NetEConst*rc = dynamic_cast<NetEConst*>(right_);
if (rc == 0) return 0;
verinum::V lv = verinum::V0;
verinum::V rv = verinum::V0;
verinum v = lc->value();
for (unsigned idx = 0 ; idx < v.len() ; idx += 1)
if (v.get(idx) == verinum::V1)
lv = verinum::V1;
if (lv == verinum::V0)
for (unsigned idx = 0 ; idx < v.len() ; idx += 1)
if (v.get(idx) != verinum::V0)
lv = verinum::Vx;
v = rc->value();
for (unsigned idx = 0 ; idx < v.len() ; idx += 1)
if (v.get(idx) == verinum::V1)
rv = verinum::V1;
if (lv == verinum::V0)
for (unsigned idx = 0 ; idx < v.len() ; idx += 1)
if (v.get(idx) != verinum::V0)
rv = verinum::Vx;
verinum::V res;
switch (op_) {
case 'a': { // Logical AND (&&)
if ((lv == verinum::V0) || (rv == verinum::V0))
res = verinum::V0;
else if ((lv == verinum::V1) && (rv == verinum::V1))
res = verinum::V1;
else
res = verinum::Vx;
break;
}
case 'o': { // Logical OR (||)
if ((lv == verinum::V1) || (rv == verinum::V1))
res = verinum::V1;
else if ((lv == verinum::V0) && (rv == verinum::V0))
res = verinum::V0;
else
res = verinum::Vx;
break;
}
default:
return 0;
}
return new NetEConst(verinum(res, 1));
}
NetEConst* NetEBMult::eval_tree()
@ -701,6 +761,9 @@ NetEConst* NetEUReduce::eval_tree()
/*
* $Log: eval_tree.cc,v $
* Revision 1.19 2001/01/04 04:28:42 steve
* Evaluate constant logical && and ||.
*
* Revision 1.18 2001/01/02 04:21:14 steve
* Support a bunch of unary operators in parameter expressions.
*