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iverilog/elab_pexpr.cc

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/*
* Copyright (c) 2000 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: elab_pexpr.cc,v 1.16 2002/08/12 01:34:59 steve Exp $"
#endif
# include "config.h"
# include "PExpr.h"
# include "util.h"
# include <iostream>
NetExpr*PExpr::elaborate_pexpr(Design*des, NetScope*sc) const
{
cerr << get_line() << ": error: invalid parameter expression: "
<< *this << endl;
des->errors += 1;
return 0;
}
/*
* Binary operators have sub-expressions that must be elaborated as
* parameter expressions. If either of them fail, then give up. Once
* they are taken care of, make the base object just as in any other
* expression.
*/
NetExpr*PEBinary::elaborate_pexpr (Design*des, NetScope*scope) const
{
NetExpr*lp = left_->elaborate_pexpr(des, scope);
NetExpr*rp = right_->elaborate_pexpr(des, scope);
if ((lp == 0) || (rp == 0)) {
delete lp;
delete rp;
return 0;
}
NetEBinary*tmp = elaborate_expr_base_(des, lp, rp);
return tmp;
}
/*
* Event though parameters are not generally sized, parameter
* expressions can include concatenation expressions. This requires
* that the subexpressions all have well-defined size (in spite of
* being in a parameter expression) in order to get a defined
* value. The sub-expressions themsilves must also be value parameter
* expressions.
*/
NetEConcat* PEConcat::elaborate_pexpr(Design*des, NetScope*scope) const
{
NetExpr* repeat = 0;
/* If there is a repeat expression, then evaluate the constant
value and set the repeat count. */
if (repeat_) {
repeat = repeat_->elaborate_pexpr(des, scope);
if (repeat == 0) {
cerr << get_line() << ": error: "
"concatenation repeat expression cannot be evaluated."
<< endl;
des->errors += 1;
}
/* continue on even if the repeat expression doesn't
work, as we can find more errors. */
}
/* Make the empty concat expression. */
NetEConcat*tmp = new NetEConcat(parms_.count(), repeat);
tmp->set_line(*this);
/* Elaborate all the operands and attach them to the concat
node. Use the elaborate_pexpr method instead of the
elaborate_expr method. */
for (unsigned idx = 0 ; idx < parms_.count() ; idx += 1) {
assert(parms_[idx]);
NetExpr*ex = parms_[idx]->elaborate_pexpr(des, scope);
if (ex == 0) continue;
ex->set_line(*parms_[idx]);
if (dynamic_cast<NetEParam*>(ex)) {
/* If this parameter is a NetEParam, then put off
the width check for later. */
} else if (! ex->has_width()) {
cerr << ex->get_line() << ": error: operand of "
<< "concatenation has indefinite width: "
<< *ex << endl;
des->errors += 1;
} else if (ex->expr_width() == 0) {
cerr << ex->get_line() << ": internal error: "
<< "Operand of concatenation has no width: "
<< *ex << endl;
des->errors += 1;
}
tmp->set(idx, ex);
}
return tmp;
}
NetExpr*PEFNumber::elaborate_pexpr(Design*des, NetScope*scope) const
{
return elaborate_expr(des, scope);
}
/*
* Parameter expressions may reference other parameters, but only in
* the current scope. Preserve the parameter reference in the
* parameter expression I'm generating, instead of evaluating it now,
* because the referenced parameter may yet be overridden.
*/
NetExpr*PEIdent::elaborate_pexpr(Design*des, NetScope*scope) const
{
hname_t path = path_;
char*name = path.remove_tail_name();
NetScope*pscope = scope;
if (path.peek_name(0))
pscope = des->find_scope(scope, path);
const NetExpr*ex = pscope->get_parameter(name);
if (ex == 0) {
cerr << get_line() << ": error: identifier ``" << path_ <<
"'' is not a parameter in " << scope->name() << "." << endl;
des->errors += 1;
delete name;
return 0;
}
if (msb_ || lsb_ || idx_) {
cerr << get_line() << ": error: Cannot bit/part select "
"bits of parameters." << endl;
des->errors += 1;
}
NetExpr*res = new NetEParam(des, pscope, hname_t(name));
assert(res);
delete name;
return res;
}
/*
* Simple numbers can be elaborated by the elaborate_expr method.
*/
NetExpr*PENumber::elaborate_pexpr(Design*des, NetScope*sc) const
{
return elaborate_expr(des, sc);
}
NetEConst* PEString::elaborate_pexpr(Design*des, NetScope*scope) const
{
return elaborate_expr(des, scope);
}
NetETernary* PETernary::elaborate_pexpr(Design*des, NetScope*scope) const
{
NetExpr*c = expr_->elaborate_pexpr(des, scope);
NetExpr*t = tru_->elaborate_pexpr(des, scope);
NetExpr*f = fal_->elaborate_pexpr(des, scope);
if (c == 0) return 0;
if (t == 0) return 0;
if (f == 0) return 0;
return new NetETernary(c, t, f);
}
NetExpr*PEUnary::elaborate_pexpr (Design*des, NetScope*scope) const
{
NetExpr*ip = expr_->elaborate_pexpr(des, scope);
if (ip == 0) return 0;
/* Should we evaluate expressions ahead of time,
* just like in PEBinary::elaborate_expr() ?
*/
NetEUnary*tmp;
switch (op_) {
default:
tmp = new NetEUnary(op_, ip);
tmp->set_line(*this);
break;
case '~':
tmp = new NetEUBits(op_, ip);
tmp->set_line(*this);
break;
case '!': // Logical NOT
case '&': // Reduction AND
case '|': // Reduction OR
case '^': // Reduction XOR
case 'A': // Reduction NAND (~&)
case 'N': // Reduction NOR (~|)
case 'X': // Reduction NXOR (~^)
tmp = new NetEUReduce(op_, ip);
tmp->set_line(*this);
break;
}
return tmp;
}
/*
* $Log: elab_pexpr.cc,v $
* Revision 1.16 2002/08/12 01:34:59 steve
* conditional ident string using autoconfig.
*
* Revision 1.15 2002/05/06 02:30:27 steve
* Allow parameters in concatenation of widths are defined.
*
* Revision 1.14 2002/05/05 21:11:50 steve
* Put off evaluation of concatenation repeat expresions
* until after parameters are defined. This allows parms
* to be used in repeat expresions.
*
* Add the builtin $signed system function.
*
* Revision 1.13 2002/01/28 00:52:41 steve
* Add support for bit select of parameters.
* This leads to a NetESelect node and the
* vvp code generator to support that.
*
* Revision 1.12 2001/12/03 04:47:14 steve
* Parser and pform use hierarchical names as hname_t
* objects instead of encoded strings.
*
* Revision 1.11 2001/11/07 04:01:59 steve
* eval_const uses scope instead of a string path.
*
* Revision 1.10 2001/10/07 03:38:08 steve
* parameter names do not have defined size.
*
* Revision 1.9 2001/07/25 03:10:49 steve
* Create a config.h.in file to hold all the config
* junk, and support gcc 3.0. (Stephan Boettcher)
*
* Revision 1.8 2001/01/14 23:04:56 steve
* Generalize the evaluation of floating point delays, and
* get it working with delay assignment statements.
*
* Allow parameters to be referenced by hierarchical name.
*
* Revision 1.7 2001/01/02 04:21:13 steve
* Support a bunch of unary operators in parameter expressions.
*
* Revision 1.6 2000/12/16 19:03:30 steve
* Evaluate <= and ?: in parameter expressions (PR#81)
*
* Revision 1.5 2000/06/13 05:22:16 steve
* Support concatenation in parameter expressions.
*
* Revision 1.4 2000/06/01 02:31:39 steve
* Parameters can be strings.
*
* Revision 1.3 2000/03/12 18:22:11 steve
* Binary and unary operators in parameter expressions.
*
* Revision 1.2 2000/03/12 04:35:22 steve
* Allow parameter identifiers in parameter expressions.
*
* Revision 1.1 2000/03/08 04:36:53 steve
* Redesign the implementation of scopes and parameters.
* I now generate the scopes and notice the parameters
* in a separate pass over the pform. Once the scopes
* are generated, I can process overrides and evalutate
* paremeters before elaboration begins.
*
*/
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