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Less agressive padding of unsized lossless addition. 

When doing lossless addition to an unsized constant, we make the size
be width of an integer, only to be consistent with other tools. In fact,
don't go overboard if we don't have to.
This commit is contained in:
Stephen Williams 2008-10-10 20:45:11 -07:00
parent c85eff93f2
commit a9497e9c6a
1 changed files with 24 additions and 12 deletions
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36
net_expr.cc
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@ -56,42 +56,54 @@ NetEBAdd::NetEBAdd(char op, NetExpr*l, NetExpr*r, bool lossless_flag)
&& (! tmp->has_width())
&& (tmp->expr_width() > l->expr_width() || integer_width > l->expr_width()) ) {
unsigned target_width = l->expr_width() + 1;
verinum tmp_v = trim_vnum(tmp->value());
unsigned target_width = l->expr_width();
if (target_width < tmp_v.len())
target_width = tmp_v.len();
if (lossless_flag)
target_width += 1;
if (target_width < integer_width)
target_width = integer_width;
r->set_width(target_width);
/* Note: This constant value will not gain a defined
width from this. Make sure. */
assert(! r->has_width() );
expr_width(target_width);
} else if ( (tmp = dynamic_cast<NetEConst*>(l))
&& (! tmp->has_width())
&& (tmp->expr_width() > r->expr_width() || integer_width > r->expr_width()) ) {
unsigned target_width = r->expr_width() + 1;
verinum tmp_v = trim_vnum(tmp->value());
unsigned target_width = r->expr_width();
if (target_width < tmp_v.len())
target_width = tmp_v.len();
if (lossless_flag)
target_width += 1;
if (target_width < integer_width)
target_width = integer_width;
l->set_width(target_width);
/* Note: This constant value will not gain a defined
width from this. Make sure. */
assert(! l->has_width() );
}
expr_width(target_width);
unsigned pad_width = lossless_flag? 1 : 0;
cast_signed(l->has_sign() && r->has_sign());
/* Now that we have the operand sizes the way we like, or as
good as we are going to get them, set the size of myself. */
if (r->expr_width() > l->expr_width()) {
expr_width(r->expr_width() + pad_width);
} else if (r->expr_width() > l->expr_width()) {
unsigned loss_pad = lossless_flag? 1 : 0;
expr_width(r->expr_width() + loss_pad);
} else {
expr_width(l->expr_width() + pad_width);
unsigned loss_pad = lossless_flag? 1 : 0;
expr_width(l->expr_width() + loss_pad);
}
cast_signed(l->has_sign() && r->has_sign());
}
NetEBAdd::~NetEBAdd()