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elab_expr.cc
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elab_expr.cc
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/*
* Copyright (c) 1999-2008 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
*/
# include "config.h"
# include <typeinfo>
# include <cstdlib>
# include <cstring>
# include "compiler.h"
# include "pform.h"
# include "netlist.h"
# include "netmisc.h"
# include "util.h"
# include "ivl_assert.h"
/*
* The default behavior for the test_width method is to just return the
* minimum width that is passed in.
*/
unsigned PExpr::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval, bool&) const
{
if (debug_elaborate) {
cerr << get_fileline() << ": debug: test_width defaults to "
<< min << ", ignoring unsized_flag. typeid="
<< typeid(*this).name() << endl;
}
return min;
}
NetExpr* PExpr::elaborate_expr(Design*des, NetScope*, int, bool) const
{
cerr << get_fileline() << ": internal error: I do not know how to elaborate"
<< " expression. " << endl;
cerr << get_fileline() << ": : Expression is: " << *this
<< endl;
des->errors += 1;
return 0;
}
unsigned PEBinary::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval, bool&unsized_flag) const
{
bool flag_left = false;
bool flag_right = false;
unsigned wid_left = left_->test_width(des,scope, min, lval, flag_left);
unsigned wid_right = right_->test_width(des,scope, min, lval, flag_right);
if (flag_left || flag_right)
unsized_flag = true;
switch (op_) {
case '+':
case '-':
if (unsized_flag) {
wid_left += 1;
wid_right += 1;
}
if (wid_left > min)
min = wid_left;
if (wid_right > min)
min = wid_right;
if (lval > 0 && min > lval)
min = lval;
break;
default:
if (wid_left > min)
min = wid_left;
if (wid_right > min)
min = wid_right;
break;
}
return min;
}
/*
* Elaborate binary expressions. This involves elaborating the left
* and right sides, and creating one of a variety of different NetExpr
* types.
*/
NetExpr* PEBinary::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool) const
{
assert(left_);
assert(right_);
NetExpr*lp = left_->elaborate_expr(des, scope, expr_wid, false);
NetExpr*rp = right_->elaborate_expr(des, scope, expr_wid, false);
if ((lp == 0) || (rp == 0)) {
delete lp;
delete rp;
return 0;
}
NetExpr*tmp = elaborate_eval_expr_base_(des, lp, rp, expr_wid);
return tmp;
}
void PEBinary::suppress_operand_sign_if_needed_(NetExpr*lp, NetExpr*rp)
{
// If either operand is unsigned, then treat the whole
// expression as unsigned. This test needs to be done here
// instead of in *_expr_base_ because it needs to be done
// ahead of any subexpression evaluation (because they need to
// know their signedness to evaluate) and because there are
// exceptions to this rule.
if (! lp->has_sign())
rp->cast_signed(false);
if (! rp->has_sign())
lp->cast_signed(false);
}
NetExpr* PEBinary::elaborate_eval_expr_base_(Design*des,
NetExpr*lp,
NetExpr*rp,
int expr_wid) const
{
/* If either expression can be evaluated ahead of time, then
do so. This can prove helpful later. */
eval_expr(lp);
eval_expr(rp);
return elaborate_expr_base_(des, lp, rp, expr_wid);
}
/*
* This is common elaboration of the operator. It presumes that the
* operands are elaborated as necessary, and all I need to do is make
* the correct NetEBinary object and connect the parameters.
*/
NetExpr* PEBinary::elaborate_expr_base_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
bool flag;
if (debug_elaborate) {
cerr << get_fileline() << ": debug: elaborate expression "
<< *this << " expr_wid=" << expr_wid << endl;
}
NetExpr*tmp;
switch (op_) {
default:
tmp = new NetEBinary(op_, lp, rp);
tmp->set_line(*this);
break;
case 'a':
case 'o':
lp = condition_reduce(lp);
rp = condition_reduce(rp);
tmp = new NetEBLogic(op_, lp, rp);
tmp->set_line(*this);
break;
case 'p':
tmp = new NetEBPow(op_, lp, rp);
tmp->set_line(*this);
break;
case '*':
tmp = new NetEBMult(op_, lp, rp);
tmp->set_line(*this);
break;
case '%':
/* The % operator does not support real arguments in
baseline Verilog. But we allow it in our extended
form of Verilog. */
if (! gn_icarus_misc_flag) {
if (lp->expr_type()==IVL_VT_REAL ||
rp->expr_type()==IVL_VT_REAL) {
cerr << get_fileline() << ": error: Modulus operator "
"may not have REAL operands." << endl;
des->errors += 1;
}
}
/* Fall through to handle the % with the / operator. */
case '/':
tmp = new NetEBDiv(op_, lp, rp);
tmp->set_line(*this);
break;
case 'l': // <<
if (NetEConst*lpc = dynamic_cast<NetEConst*> (lp)) {
if (NetEConst*rpc = dynamic_cast<NetEConst*> (rp)) {
// Handle the super-special case that both
// operands are constants. Precalculate the
// entire value here.
verinum lpval = lpc->value();
unsigned shift = rpc->value().as_ulong();
verinum result = lpc->value() << shift;
// If the l-value has explicit size, or
// there is a context determined size, use that.
if (lpval.has_len() || expr_wid > 0) {
int use_len = lpval.len();
if (expr_wid < use_len)
use_len = expr_wid;
result = verinum(result, lpval.len());
}
tmp = new NetEConst(result);
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Precalculate " << *this
<< " to constant " << *tmp << endl;
} else {
// Handle the special case that the left
// operand is constant. If it is unsized, we
// may have to expand it to an integer width.
verinum lpval = lpc->value();
if (lpval.len() < integer_width && !lpval.has_len()) {
lpval = verinum(lpval, integer_width);
lpc = new NetEConst(lpval);
lpc->set_line(*lp);
}
tmp = new NetEBShift(op_, lpc, rp);
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Adjust " << *this
<< " to this " << *tmp
<< " to allow for integer widths." << endl;
}
} else {
// Left side is not constant, so handle it the
// default way.
tmp = new NetEBShift(op_, lp, rp);
}
tmp->set_line(*this);
break;
case 'r': // >>
case 'R': // >>>
tmp = new NetEBShift(op_, lp, rp);
tmp->set_line(*this);
break;
case '^':
case '&':
case '|':
case 'O': // NOR (~|)
case 'A': // NAND (~&)
case 'X':
tmp = new NetEBBits(op_, lp, rp);
tmp->set_line(*this);
break;
case '+':
case '-':
tmp = new NetEBAdd(op_, lp, rp, expr_wid==-2? true : false);
if (expr_wid > 0 && (tmp->expr_type() == IVL_VT_BOOL
|| tmp->expr_type() == IVL_VT_LOGIC))
tmp->set_width(expr_wid);
tmp->set_line(*this);
break;
case 'E': /* === */
case 'N': /* !== */
if (lp->expr_type() == IVL_VT_REAL ||
rp->expr_type() == IVL_VT_REAL) {
cerr << get_fileline() << ": error: "
<< human_readable_op(op_)
<< "may not have real operands." << endl;
return 0;
}
/* Fall through... */
case 'e': /* == */
case 'n': /* != */
if (dynamic_cast<NetEConst*>(rp)
&& (lp->expr_width() > rp->expr_width()))
rp->set_width(lp->expr_width());
if (dynamic_cast<NetEConst*>(lp)
&& (lp->expr_width() < rp->expr_width()))
lp->set_width(rp->expr_width());
/* from here, handle this like other compares. */
case 'L': /* <= */
case 'G': /* >= */
case '<':
case '>':
tmp = new NetEBComp(op_, lp, rp);
tmp->set_line(*this);
flag = tmp->set_width(1);
if (flag == false) {
cerr << get_fileline() << ": internal error: "
"expression bit width of comparison != 1." << endl;
des->errors += 1;
}
break;
case 'm': // min(l,r)
case 'M': // max(l,r)
tmp = new NetEBMinMax(op_, lp, rp);
tmp->set_line(*this);
break;
}
return tmp;
}
unsigned PEBComp::test_width(Design*, NetScope*,unsigned, unsigned, bool&) const
{
return 1;
}
NetExpr* PEBComp::elaborate_expr(Design*des, NetScope*scope,
int expr_width, bool sys_task_arg) const
{
assert(left_);
assert(right_);
bool unsized_flag = false;
unsigned left_width = left_->test_width(des, scope, 0, 0, unsized_flag);
bool save_flag = unsized_flag;
unsigned right_width = right_->test_width(des, scope, 0, 0, unsized_flag);
if (save_flag != unsized_flag)
left_width = left_->test_width(des, scope, 0, 0, unsized_flag);
/* Width of operands is self-determined. */
int use_wid = left_width;
if (right_width > left_width)
use_wid = right_width;
if (debug_elaborate) {
cerr << get_fileline() << ": debug: "
<< "Comparison expression operands are "
<< left_width << " bits and "
<< right_width << " bits. Resorting to "
<< use_wid << " bits." << endl;
}
NetExpr*lp = left_->elaborate_expr(des, scope, use_wid, false);
NetExpr*rp = right_->elaborate_expr(des, scope, use_wid, false);
if ((lp == 0) || (rp == 0)) {
delete lp;
delete rp;
return 0;
}
suppress_operand_sign_if_needed_(lp, rp);
return elaborate_eval_expr_base_(des, lp, rp, use_wid);
}
unsigned PEBShift::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval, bool&unsized_flag) const
{
unsigned wid_left = left_->test_width(des,scope,min, 0, unsized_flag);
// The right expression is self-determined and has no impact
// on the expression size that is generated.
return wid_left;
}
unsigned PECallFunction::test_width_sfunc_(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const
{
perm_string name = peek_tail_name(path_);
if (name=="$signed"|| name=="$unsigned") {
PExpr*expr = parms_[0];
if (expr == 0)
return 0;
unsigned wid = expr->test_width(des, scope, min, lval, unsized_flag);
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width"
<< " of $signed/$unsigned returns test_width"
<< " of subexpression." << endl;
return wid;
}
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width "
<< "of system function " << name
<< " returns 32 always?" << endl;
return 32;
}
unsigned PECallFunction::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const
{
if (peek_tail_name(path_)[0] == '$')
return test_width_sfunc_(des, scope, min, lval, unsized_flag);
NetFuncDef*def = des->find_function(scope, path_);
if (def == 0) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width "
<< "cannot find definition of " << path_
<< " in " << scope_path(scope) << "." << endl;
return 0;
}
NetScope*dscope = def->scope();
assert(dscope);
if (NetNet*res = dscope->find_signal(dscope->basename())) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width "
<< "of function returns width " << res->vector_width()
<< "." << endl;
return res->vector_width();
}
ivl_assert(*this, 0);
return 0;
}
/*
* Given a call to a system function, generate the proper expression
* nodes to represent the call in the netlist. Since we don't support
* size_tf functions, make assumptions about widths based on some
* known function names.
*/
NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*scope, int expr_wid) const
{
/* Catch the special case that the system function is the
$signed function. This function is special, in that it does
not lead to executable code but takes the single parameter
and makes it into a signed expression. No bits are changed,
it just changes the interpretation. */
if (strcmp(peek_tail_name(path_), "$signed") == 0) {
if ((parms_.count() != 1) || (parms_[0] == 0)) {
cerr << get_fileline() << ": error: The $signed() function "
<< "takes exactly one(1) argument." << endl;
des->errors += 1;
return 0;
}
PExpr*expr = parms_[0];
NetExpr*sub = expr->elaborate_expr(des, scope, -1, true);
sub->cast_signed(true);
return sub;
}
/* add $unsigned to match $signed */
if (strcmp(peek_tail_name(path_), "$unsigned") == 0) {
if ((parms_.count() != 1) || (parms_[0] == 0)) {
cerr << get_fileline() << ": error: The $unsigned() function "
<< "takes exactly one(1) argument." << endl;
des->errors += 1;
return 0;
}
PExpr*expr = parms_[0];
NetExpr*sub = expr->elaborate_expr(des, scope, -1, true);
sub->cast_signed(false);
if (expr_wid > 0 && (unsigned)expr_wid > sub->expr_width())
sub = pad_to_width(sub, expr_wid);
return sub;
}
/* Interpret the internal $sizeof system function to return
the bit width of the sub-expression. The value of the
sub-expression is not used, so the expression itself can be
deleted. */
if ((strcmp(peek_tail_name(path_), "$sizeof") == 0)
|| (strcmp(peek_tail_name(path_), "$bits") == 0)) {
if ((parms_.count() != 1) || (parms_[0] == 0)) {
cerr << get_fileline() << ": error: The $bits() function "
<< "takes exactly one(1) argument." << endl;
des->errors += 1;
return 0;
}
if (strcmp(peek_tail_name(path_), "$sizeof") == 0)
cerr << get_fileline() << ": warning: $sizeof is deprecated."
<< " Use $bits() instead." << endl;
PExpr*expr = parms_[0];
ivl_assert(*this, expr);
/* Elaborate the sub-expression to get its
self-determined width, and save that width. Then
delete the expression because we don't really want
the expression itself. */
long sub_expr_width = 0;
if (NetExpr*tmp = expr->elaborate_expr(des, scope, -1, true)) {
sub_expr_width = tmp->expr_width();
delete tmp;
}
verinum val (sub_expr_width, 8*sizeof(unsigned));
NetEConst*sub = new NetEConst(val);
sub->set_line(*this);
return sub;
}
/* Interpret the internal $is_signed system function to return
a single bit flag -- 1 if the expression is signed, 0
otherwise. The subexpression is elaborated but not
evaluated. */
if (strcmp(peek_tail_name(path_), "$is_signed") == 0) {
if ((parms_.count() != 1) || (parms_[0] == 0)) {
cerr << get_fileline() << ": error: The $is_signed() function "
<< "takes exactly one(1) argument." << endl;
des->errors += 1;
return 0;
}
PExpr*expr = parms_[0];
NetExpr*sub = expr->elaborate_expr(des, scope, -1, true);
verinum val (sub->has_sign()? verinum::V1 : verinum::V0, 1);
delete sub;
sub = new NetEConst(val);
sub->set_line(*this);
return sub;
}
/* Get the return type of the system function by looking it up
in the sfunc_table. */
const struct sfunc_return_type*sfunc_info
= lookup_sys_func(peek_tail_name(path_));
ivl_variable_type_t sfunc_type = sfunc_info->type;
unsigned wid = sfunc_info->wid;
/* How many parameters are there? The Verilog language allows
empty parameters in certain contexts, so the parser will
allow things like func(1,,3). It will also cause func() to
be interpreted as a single empty parameter.
Functions cannot really take empty parameters, but the
case ``func()'' is the same as no parameters at all. So
catch that special case here. */
unsigned nparms = parms_.count();
if ((nparms == 1) && (parms_[0] == 0))
nparms = 0;
NetESFunc*fun = new NetESFunc(peek_tail_name(path_), sfunc_type,
wid, nparms);
fun->set_line(*this);
if (sfunc_info->signed_flag)
fun->cast_signed(true);
/* Now run through the expected parameters. If we find that
there are missing parameters, print an error message.
While we're at it, try to evaluate the function parameter
expression as much as possible, and use the reduced
expression if one is created. */
unsigned missing_parms = 0;
for (unsigned idx = 0 ; idx < nparms ; idx += 1) {
PExpr*expr = parms_[idx];
if (expr) {
NetExpr*tmp1 = expr->elaborate_expr(des, scope, -1, true);
eval_expr(tmp1);
fun->parm(idx, tmp1);
} else {
missing_parms += 1;
fun->parm(idx, 0);
}
}
if (missing_parms > 0) {
cerr << get_fileline() << ": error: The function "
<< peek_tail_name(path_)
<< " has been called with empty parameters." << endl;
cerr << get_fileline() << ": : Verilog doesn't allow "
<< "passing empty parameters to functions." << endl;
des->errors += 1;
}
return fun;
}
NetExpr* PECallFunction::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool) const
{
if (peek_tail_name(path_)[0] == '$')
return elaborate_sfunc_(des, scope, expr_wid);
NetFuncDef*def = des->find_function(scope, path_);
if (def == 0) {
cerr << get_fileline() << ": error: No function " << path_ <<
" in this context (" << scope_path(scope) << ")." << endl;
des->errors += 1;
return 0;
}
assert(def);
NetScope*dscope = def->scope();
assert(dscope);
if (! check_call_matches_definition_(des, dscope))
return 0;
unsigned parms_count = parms_.count();
if ((parms_count == 1) && (parms_[0] == 0))
parms_count = 0;
svector<NetExpr*> parms (parms_count);
/* Elaborate the input expressions for the function. This is
done in the scope of the function call, and not the scope
of the function being called. The scope of the called
function is elaborated when the definition is elaborated. */
unsigned missing_parms = 0;
for (unsigned idx = 0 ; idx < parms.count() ; idx += 1) {
PExpr*tmp = parms_[idx];
if (tmp) {
int argwid = def->port(idx)->vector_width();
parms[idx] = elab_and_eval(des, scope, tmp, argwid);
if (debug_elaborate)
cerr << get_fileline() << ": debug:"
<< " function " << path_
<< " arg " << (idx+1)
<< " argwid=" << argwid
<< ": " << *parms[idx] << endl;
} else {
missing_parms += 1;
parms[idx] = 0;
}
}
if (missing_parms > 0) {
cerr << get_fileline() << ": error: The function " << path_
<< " has been called with empty parameters." << endl;
cerr << get_fileline() << ": : Verilog doesn't allow "
<< "passing empty parameters to functions." << endl;
des->errors += 1;
}
/* Look for the return value signal for the called
function. This return value is a magic signal in the scope
of the function, that has the name of the function. The
function code assigns to this signal to return a value.
dscope, in this case, is the scope of the function, so the
return value is the name within that scope. */
if (NetNet*res = dscope->find_signal(dscope->basename())) {
NetESignal*eres = new NetESignal(res);
NetEUFunc*func = new NetEUFunc(scope, dscope, eres, parms);
func->set_line(*this);
func->cast_signed(res->get_signed());
return func;
}
cerr << get_fileline() << ": internal error: Unable to locate "
"function return value for " << path_
<< " in " << dscope->basename() << "." << endl;
des->errors += 1;
return 0;
}
// Keep track of the concatenation/repeat depth.
static int concat_depth = 0;
NetExpr* PEConcat::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool) const
{
concat_depth += 1;
NetExpr* repeat = 0;
if (debug_elaborate) {
cerr << get_fileline() << ": debug: Elaborate expr=" << *this
<< ", expr_wid=" << expr_wid << endl;
}
/* If there is a repeat expression, then evaluate the constant
value and set the repeat count. */
if (repeat_) {
NetExpr*tmp = elab_and_eval(des, scope, repeat_, -1);
assert(tmp);
NetEConst*rep = dynamic_cast<NetEConst*>(tmp);
if (rep == 0) {
cerr << get_fileline() << ": error: "
"concatenation repeat expression cannot be evaluated."
<< endl;
cerr << get_fileline() << ": : The expression is: "
<< *tmp << endl;
des->errors += 1;
}
if (rep->value().is_negative()) {
cerr << get_fileline() << ": error: Concatenation repeat "
<< "may not be negative (" << rep->value().as_long()
<< ")." << endl;
des->errors += 1;
concat_depth -= 1;
return 0;
}
if (rep->value().is_zero() && concat_depth < 2) {
cerr << get_fileline() << ": error: Concatenation repeat "
<< "may not be zero in this context." << endl;
des->errors += 1;
concat_depth -= 1;
return 0;
}
repeat = rep;
}
/* Make the empty concat expression. */
NetEConcat*tmp = new NetEConcat(parms_.count(), repeat);
tmp->set_line(*this);
unsigned wid_sum = 0;
/* Elaborate all the parameters and attach them to the concat node. */
for (unsigned idx = 0 ; idx < parms_.count() ; idx += 1) {
if (parms_[idx] == 0) {
cerr << get_fileline() << ": error: Missing expression "
<< (idx+1) << " of concatenation list." << endl;
des->errors += 1;
continue;
}
assert(parms_[idx]);
NetExpr*ex = elab_and_eval(des, scope, parms_[idx], 0, 0);
if (ex == 0) continue;
ex->set_line(*parms_[idx]);
if (! ex->has_width()) {
cerr << ex->get_fileline() << ": error: operand of "
<< "concatenation has indefinite width: "
<< *ex << endl;
des->errors += 1;
}
wid_sum += ex->expr_width();
tmp->set(idx, ex);
}
tmp->set_width(wid_sum * tmp->repeat());
if (wid_sum == 0 && concat_depth < 2) {
cerr << get_fileline() << ": error: Concatenation may not "
<< "have zero width in this context." << endl;
des->errors += 1;
concat_depth -= 1;
return 0;
}
concat_depth -= 1;
return tmp;
}
NetExpr* PEFNumber::elaborate_expr(Design*des, NetScope*scope, int, bool) const
{
NetECReal*tmp = new NetECReal(*value_);
tmp->set_line(*this);
tmp->set_width(1U, false);
return tmp;
}
/*
* Given that the msb_ and lsb_ are part select expressions, this
* function calculates their values. Note that this method does *not*
* convert the values to canonical form.
*/
bool PEIdent::calculate_parts_(Design*des, NetScope*scope,
long&msb, long&lsb) const
{
const name_component_t&name_tail = path_.back();
ivl_assert(*this, !name_tail.index.empty());
const index_component_t&index_tail = name_tail.index.back();
ivl_assert(*this, index_tail.sel == index_component_t::SEL_PART);
ivl_assert(*this, index_tail.msb && index_tail.lsb);
/* This handles part selects. In this case, there are
two bit select expressions, and both must be
constant. Evaluate them and pass the results back to
the caller. */
NetExpr*lsb_ex = elab_and_eval(des, scope, index_tail.lsb, -1);
NetEConst*lsb_c = dynamic_cast<NetEConst*>(lsb_ex);
if (lsb_c == 0) {
cerr << index_tail.lsb->get_fileline() << ": error: "
"Part select expressions must be constant."
<< endl;
cerr << index_tail.lsb->get_fileline() << ": : "
"This lsb expression violates the rule: "
<< *index_tail.lsb << endl;
des->errors += 1;
return false;
}
NetExpr*msb_ex = elab_and_eval(des, scope, index_tail.msb, -1);
NetEConst*msb_c = dynamic_cast<NetEConst*>(msb_ex);
if (msb_c == 0) {
cerr << index_tail.msb->get_fileline() << ": error: "
"Part select expressions must be constant."
<< endl;
cerr << index_tail.msb->get_fileline() << ": : This msb expression "
"violates the rule: " << *index_tail.msb << endl;
des->errors += 1;
return false;
}
msb = msb_c->value().as_long();
lsb = lsb_c->value().as_long();
delete msb_ex;
delete lsb_ex;
return true;
}
bool PEIdent::calculate_up_do_width_(Design*des, NetScope*scope,
unsigned long&wid) const
{
const name_component_t&name_tail = path_.back();
ivl_assert(*this, !name_tail.index.empty());
const index_component_t&index_tail = name_tail.index.back();
ivl_assert(*this, index_tail.lsb && index_tail.msb);
bool flag = true;
/* Calculate the width expression (in the lsb_ position)
first. If the expression is not constant, error but guess 1
so we can keep going and find more errors. */
NetExpr*wid_ex = elab_and_eval(des, scope, index_tail.lsb, -1);
NetEConst*wid_c = dynamic_cast<NetEConst*>(wid_ex);
if (wid_c == 0) {
cerr << get_fileline() << ": error: Indexed part width must be "
<< "constant. Expression in question is..." << endl;
cerr << get_fileline() << ": : " << *wid_ex << endl;
des->errors += 1;
flag = false;
}
wid = wid_c? wid_c->value().as_ulong() : 1;
delete wid_ex;
return flag;
}
unsigned PEIdent::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
bool&unsized_flag) const
{
NetNet* net = 0;
const NetExpr*par = 0;
NetEvent* eve = 0;
const NetExpr*ex1, *ex2;
symbol_search(des, scope, path_, net, par, eve, ex1, ex2);
if (net != 0) {
const name_component_t&name_tail = path_.back();
index_component_t::ctype_t use_sel = index_component_t::SEL_NONE;
if (!name_tail.index.empty())
use_sel = name_tail.index.back().sel;
unsigned use_width = net->vector_width();
switch (use_sel) {
case index_component_t::SEL_NONE:
break;
case index_component_t::SEL_PART:
{ long msb, lsb;
calculate_parts_(des, scope, msb, lsb);
use_width = 1 + ((msb>lsb)? (msb-lsb) : (lsb-msb));
break;
}
case index_component_t::SEL_IDX_UP:
case index_component_t::SEL_IDX_DO:
{ unsigned long tmp = 0;
calculate_up_do_width_(des, scope, tmp);
use_width = tmp;
break;
}
case index_component_t::SEL_BIT:
use_width = 1;
break;
default:
ivl_assert(*this, 0);
}
return use_width;
}
return min;
}
/*
* Elaborate an identifier in an expression. The identifier can be a
* parameter name, a signal name or a memory name. It can also be a
* scope name (Return a NetEScope) but only certain callers can use
* scope names. However, we still support it here.
*
* Function names are not handled here, they are detected by the
* parser and are elaborated by PECallFunction.
*
* The signal name may be escaped, but that affects nothing here.
*/
NetExpr* PEIdent::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool sys_task_arg) const
{
assert(scope);
NetNet* net = 0;
const NetExpr*par = 0;
NetEvent* eve = 0;
const NetExpr*ex1, *ex2;
NetScope*found_in = symbol_search(des, scope, path_,
net, par, eve,
ex1, ex2);
// If the identifier name is a parameter name, then return
// a reference to the parameter expression.
if (par != 0)
return elaborate_expr_param(des, scope, par, found_in, ex1, ex2);
// If the identifier names a signal (a register or wire)
// then create a NetESignal node to handle it.
if (net != 0)
return elaborate_expr_net(des, scope, net, found_in, sys_task_arg);
// If the identifier is a named event.
// is a variable reference.
if (eve != 0) {
NetEEvent*tmp = new NetEEvent(eve);
tmp->set_line(*this);
return tmp;
}
// Hmm... maybe this is a genvar? This is only possible while
// processing generate blocks, but then the genvar_tmp will be
// set in the scope.
if (path_.size() == 1
&& scope->genvar_tmp.str()
&& strcmp(peek_tail_name(path_), scope->genvar_tmp) == 0) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: " << path_
<< " is genvar with value " << scope->genvar_tmp_val
<< "." << endl;
verinum val (scope->genvar_tmp_val);
NetEConst*tmp = new NetEConst(val);
tmp->set_line(*this);
return tmp;
}
// A specparam? Look up the name to see if it is a
// specparam. If we find it, then turn it into a NetEConst
// value and return that. Of course, this does not apply if
// specify blocks are disabled.
if (gn_specify_blocks_flag) {
map<perm_string,NetScope::spec_val_t>::const_iterator specp;
perm_string key = peek_tail_name(path_);
if (path_.size() == 1
&& ((specp = scope->specparams.find(key)) != scope->specparams.end())) {
NetScope::spec_val_t value = (*specp).second;
NetExpr*tmp = 0;
switch (value.type) {
case IVL_VT_BOOL:
tmp = new NetEConst(verinum(value.integer));
break;
case IVL_VT_REAL: