luke
/
iverilog
mirror of https://github.com/steveicarus/iverilog.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Properly handle signedness in compare.

This commit is contained in:
steve 2006-03-18 22:52:27 +00:00
parent 8defa4bcd0
commit 5b3ba8c306
2 changed files with 50 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

99
eval_tree.cc
View File

@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: eval_tree.cc,v 1.67 2005/11/27 05:56:20 steve Exp $"
#ident "$Id: eval_tree.cc,v 1.68 2006/03/18 22:52:27 steve Exp $"
#endif
# include "config.h"
@ -213,43 +213,6 @@ NetEConst* NetEBBits::eval_tree()
return new NetEConst(res);
}
NetEConst* NetEBComp::eval_eqeq_()
{
NetEConst*l = dynamic_cast<NetEConst*>(left_);
if (l == 0) return 0;
NetEConst*r = dynamic_cast<NetEConst*>(right_);
if (r == 0) return 0;
const verinum&lv = l->value();
const verinum&rv = r->value();
unsigned s_len = lv.len();
if (rv.len() < s_len) s_len = rv.len();
verinum result(verinum::V1, 1);
for (unsigned idx = 0 ; idx < s_len; idx += 1) {
if (lv[idx] != rv[idx])
result = verinum::V0;
}
// If one operand was wider than the other, check that the
// remaining bits are all zero
if (lv.len() > s_len) {
for (unsigned idx = s_len; idx < lv.len(); idx += 1) {
if (lv[idx] != 0)
result = verinum::V0;
}
}
if (rv.len() > s_len) {
for (unsigned idx = s_len; idx < rv.len(); idx += 1) {
if (rv[idx] != 0)
result = verinum::V0;
}
}
return new NetEConst(result);
}
NetEConst* NetEBComp::eval_less_()
{
@ -555,21 +518,25 @@ NetEConst* NetEBComp::eval_gteq_()
return new NetEConst(result);
}
if (lv.has_sign() && rv.has_sign() && (lv.as_long() >= rv.as_long())) {
verinum result(verinum::V1, 1);
return new NetEConst(result);
}
if (lv.has_sign() && rv.has_sign()) {
if (lv.as_ulong() >= rv.as_ulong()) {
verinum result(verinum::V1, 1);
return new NetEConst(result);
if (lv.as_long() >= rv.as_long()) {
verinum result(verinum::V1, 1);
return new NetEConst(result);
}
} else {
if (lv.as_ulong() >= rv.as_ulong()) {
verinum result(verinum::V1, 1);
return new NetEConst(result);
}
}
verinum result(verinum::V0, 1);
return new NetEConst(result);
}
NetEConst* NetEBComp::eval_neeq_()
NetEConst* NetEBComp::eval_eqeq_(bool ne_flag)
{
NetEConst*l = dynamic_cast<NetEConst*>(left_);
if (l == 0) return 0;
@ -579,7 +546,10 @@ NetEConst* NetEBComp::eval_neeq_()
const verinum&lv = l->value();
const verinum&rv = r->value();
verinum::V res = verinum::V0;
const verinum::V eq_res = ne_flag? verinum::V0 : verinum::V1;
const verinum::V ne_res = ne_flag? verinum::V1 : verinum::V0;
verinum::V res = eq_res;
unsigned top = lv.len();
if (rv.len() < top)
top = rv.len();
@ -612,10 +582,18 @@ NetEConst* NetEBComp::eval_neeq_()
break;
if (rv.get(idx) != lv.get(idx))
res = verinum::V1;
res = ne_res;
}
if (res != verinum::Vx) {
verinum::V lpad = verinum::V0;
verinum::V rpad = verinum::V0;
if (lv.has_sign() && lv.get(lv.len()-1) == verinum::V1)
lpad = verinum::V1;
if (rv.has_sign() && rv.get(rv.len()-1) == verinum::V1)
rpad = verinum::V1;
for (unsigned idx = top ; idx < lv.len() ; idx += 1)
switch (lv.get(idx)) {
@ -624,9 +602,14 @@ NetEConst* NetEBComp::eval_neeq_()
res = verinum::Vx;
break;
case verinum::V0:
if (res != verinum::Vx && rpad != verinum::V0)
res = ne_res;
break;
case verinum::V1:
if (res != verinum::Vx)
res = verinum::V1;
if (res != verinum::Vx && rpad != verinum::V1)
res = ne_res;
break;
default:
@ -641,9 +624,14 @@ NetEConst* NetEBComp::eval_neeq_()
res = verinum::Vx;
break;
case verinum::V0:
if (res != verinum::Vx && lpad != verinum::V0)
res = ne_res;
break;
case verinum::V1:
if (res != verinum::Vx)
res = verinum::V1;
if (res != verinum::Vx && lpad != verinum::V1)
res = ne_res;
break;
default:
@ -711,7 +699,7 @@ NetEConst* NetEBComp::eval_tree()
return eval_eqeqeq_();
case 'e': // Equality (==)
return eval_eqeq_();
return eval_eqeq_(false);
case 'G': // >=
return eval_gteq_();
@ -723,7 +711,7 @@ NetEConst* NetEBComp::eval_tree()
return eval_neeqeq_();
case 'n': // not-equal (!=)
return eval_neeq_();
return eval_eqeq_(true);
case '<': // Less than
return eval_less_();
@ -1601,6 +1589,9 @@ NetEConst* NetEUReduce::eval_tree()
/*
* $Log: eval_tree.cc,v $
* Revision 1.68 2006/03/18 22:52:27 steve
* Properly handle signedness in compare.
*
* Revision 1.67 2005/11/27 05:56:20 steve
* Handle bit select of parameter with ranges.
*

8
netlist.h
View File

@ -19,7 +19,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: netlist.h,v 1.355 2006/02/02 02:43:58 steve Exp $"
#ident "$Id: netlist.h,v 1.356 2006/03/18 22:53:04 steve Exp $"
#endif
/*
@ -2686,13 +2686,12 @@ class NetEBComp : public NetEBinary {
virtual NetNet* synthesize(Design*);
private:
NetEConst*eval_eqeq_();
NetEConst*eval_eqeq_(bool ne_flag);
NetEConst*eval_less_();
NetEConst*eval_leeq_();
NetEConst*eval_leeq_real_();
NetEConst*eval_gt_();
NetEConst*eval_gteq_();
NetEConst*eval_neeq_();
NetEConst*eval_eqeqeq_();
NetEConst*eval_neeqeq_();
};
@ -3459,6 +3458,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
/*
* $Log: netlist.h,v $
* Revision 1.356 2006/03/18 22:53:04 steve
* Properly handle signedness in compare.
*
* Revision 1.355 2006/02/02 02:43:58 steve
* Allow part selects of memory words in l-values.
*