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

3071 lines
91 KiB
C++
Raw Blame History

/*
* 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 <climits>
# include "compiler.h"
# include "pform.h"
# include "netlist.h"
# include "discipline.h"
# include "netmisc.h"
# include "util.h"
# include "ivl_assert.h"
bool type_is_vectorable(ivl_variable_type_t type)
{
switch (type) {
case IVL_VT_BOOL:
case IVL_VT_LOGIC:
return true;
default:
return false;
}
}
static ivl_nature_t find_access_function(const pform_name_t&path)
{
if (path.size() != 1)
return 0;
else
return access_function_nature[peek_tail_name(path)];
}
NetExpr* elaborate_rval_expr(Design*des, NetScope*scope,
ivl_variable_type_t data_type_lv, int expr_wid_lv,
PExpr*expr)
{
bool unsized_flag = type_is_vectorable(data_type_lv)? false : true;
ivl_variable_type_t rval_type = IVL_VT_NO_TYPE;
/* Find out what the r-value width is going to be. We
guess it will be the l-value width, but it may turn
out to be something else based on self-determined
widths inside. */
int expr_wid = expr->test_width(des, scope, expr_wid_lv, expr_wid_lv, rval_type, unsized_flag);
if (debug_elaborate) {
cerr << expr->get_fileline() << ": debug: r-value tested "
<< "type=" << rval_type
<< ", width=" << expr_wid
<< ", min=" << expr_wid_lv
<< ", unsized_flag=" << (unsized_flag?"true":"false") << endl;
}
switch (data_type_lv) {
case IVL_VT_REAL:
unsized_flag = true;
expr_wid = -2;
expr_wid_lv = -1;
break;
case IVL_VT_BOOL:
case IVL_VT_LOGIC:
break;
case IVL_VT_VOID:
case IVL_VT_NO_TYPE:
ivl_assert(*expr, 0);
expr_wid = -2;
expr_wid_lv = -1;
break;
}
NetExpr*result = elab_and_eval(des, scope, expr, expr_wid, expr_wid_lv);
return result;
}
/*
* 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,
ivl_variable_type_t&, bool&)
{
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,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
ivl_variable_type_t expr_type_left = IVL_VT_NO_TYPE;
ivl_variable_type_t expr_type_right= IVL_VT_NO_TYPE;
bool flag = unsized_flag;
bool flag_left = flag;
unsigned wid_left = left_->test_width(des,scope, min, 0, expr_type_left, flag_left);
bool flag_right = flag;
unsigned wid_right = right_->test_width(des,scope, min, 0, expr_type_right, flag_right);
if (flag_right && !flag) {
unsized_flag = true;
wid_left = left_->test_width(des, scope, min, 0, expr_type_left, unsized_flag);
}
if (flag_left && !flag) {
unsized_flag = true;
wid_right = right_->test_width(des, scope, min, 0, expr_type_right, unsized_flag);
}
if (expr_type_left == IVL_VT_REAL || expr_type_right == IVL_VT_REAL)
expr_type_ = IVL_VT_REAL;
else if (expr_type_left==IVL_VT_LOGIC || expr_type_right==IVL_VT_LOGIC)
expr_type_ = IVL_VT_LOGIC;
else
expr_type_ = IVL_VT_BOOL;
switch (op_) {
case '+':
case '-':
if (wid_left > min)
min = wid_left;
if (wid_right > min)
min = wid_right;
if (unsized_flag && type_is_vectorable(expr_type_))
min += 1;
break;
case '*':
if (unsized_flag && type_is_vectorable(expr_type_)) {
unsigned use_wid = wid_left + wid_right;
if (use_wid > integer_width)
use_wid = integer_width;
if (use_wid > min)
min = use_wid;
}
if (wid_left > min)
min = wid_left;
if (wid_right > min)
min = wid_right;
break;
case 'l': // << Should be handled by PEBShift
case '<': // < Should be handled by PEBComp
case '>': // > Should be handled by PEBComp
case 'e': // == Should be handled by PEBComp
case 'E': // === Should be handled by PEBComp
case 'L': // <= Should be handled by PEBComp
case 'G': // >= Should be handled by PEBComp
case 'n': // != Should be handled by PEBComp
case 'N': // !== Should be handled by PEBComp
ivl_assert(*this, 0);
default:
if (wid_left > min)
min = wid_left;
if (wid_right > min)
min = wid_right;
break;
}
if (type_is_vectorable(expr_type_))
expr_width_ = min;
else
expr_width_ = 1;
expr_type__ = expr_type_;
return expr_width_;
}
/*
* 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;
}
// Handle the special case that one of the operands is a real
// value and the other is a vector type. In that case,
// re-elaborate the vectorable argument as self-determined
// lossless.
if (lp->expr_type()==IVL_VT_REAL
&& type_is_vectorable(rp->expr_type())
&& expr_wid != -2) {
delete rp;
rp = right_->elaborate_expr(des, scope, -2, false);
}
if (rp->expr_type()==IVL_VT_REAL
&& type_is_vectorable(lp->expr_type())
&& expr_wid != -2) {
delete lp;
lp = left_->elaborate_expr(des, scope, -2, false);
}
NetExpr*tmp = elaborate_eval_expr_base_(des, lp, rp, expr_wid);
return tmp;
}
void PExpr::suppress_binary_operand_sign_if_needed_(NetExpr*lp, NetExpr*rp)
{
// If an argument is a non-vector type, then this type
// suppression does not apply.
if (! type_is_vectorable(lp->expr_type()))
return;
if (! type_is_vectorable(rp->expr_type()))
return;
// 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
{
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':
cerr << get_fileline() << ": internal error: "
<< "Elaboration of " << human_readable_op(op_)
<< " Should have been handled in NetEBLogic::elaborate."
<< endl;
des->errors += 1;
return 0;
case 'p':
tmp = new NetEBPow(op_, lp, rp);
tmp->set_line(*this);
break;
case '*':
tmp = elaborate_expr_base_mult_(des, lp, rp, expr_wid);
break;
case '%':
case '/':
tmp = elaborate_expr_base_div_(des, lp, rp, expr_wid);
break;
case 'l': // <<
tmp = elaborate_expr_base_lshift_(des, lp, rp, expr_wid);
break;
case 'r': // >>
case 'R': // >>>
tmp = elaborate_expr_base_rshift_(des, lp, rp, expr_wid);
break;
case '^':
case '&':
case '|':
case 'O': // NOR (~|)
case 'A': // NAND (~&)
case 'X':
tmp = elaborate_expr_base_bits_(des, lp, rp, expr_wid);
break;
case '+':
case '-':
tmp = elaborate_expr_base_add_(des, lp, rp, expr_wid);
break;
case 'E': /* === */
case 'N': /* !== */
case 'e': /* == */
case 'n': /* != */
case 'L': /* <= */
case 'G': /* >= */
case '<':
case '>':
cerr << get_fileline() << ": internal error: "
<< "Elaboration of " << human_readable_op(op_)
<< " Should have been handled in NetEBComp::elaborate."
<< endl;
des->errors += 1;
return 0;
case 'm': // min(l,r)
case 'M': // max(l,r)
tmp = new NetEBMinMax(op_, lp, rp);
tmp->set_line(*this);
break;
}
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_bits_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
// If either of the arguments is unsigned, then process both
// of them as unsigned. This only impacts the padding that is
// done to get the operands to the expr_wid.
if (! lp->has_sign())
rp->cast_signed(false);
if (! rp->has_sign())
lp->cast_signed(false);
if (expr_wid > 0) {
if (type_is_vectorable(lp->expr_type()))
lp = pad_to_width(lp, expr_wid);
if (type_is_vectorable(rp->expr_type()))
rp = pad_to_width(rp, expr_wid);
}
NetEBBits*tmp = new NetEBBits(op_, lp, rp);
tmp->set_line(*this);
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_div_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
/* The % operator does not support real arguments in
baseline Verilog. But we allow it in our extended
form of Verilog. */
if (op_ == '%' && ! 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;
}
}
/* The original elaboration of the left and right expressions
already tried to elaborate to the expr_wid. If the
expressions are not that width by now, then they need to be
padded. The divide expression operands must be the width
of the output. */
if (expr_wid > 0) {
lp = pad_to_width(lp, expr_wid);
rp = pad_to_width(rp, expr_wid);
}
NetEBDiv*tmp = new NetEBDiv(op_, lp, rp);
tmp->set_line(*this);
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_lshift_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
NetExpr*tmp;
long use_wid = lp->expr_width();
if (expr_wid > 0)
use_wid = expr_wid;
if (use_wid == 0) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Oops, left expression width is not known, "
<< "so expression width is not known. Punt." << endl;
tmp = new NetEBShift(op_, lp, rp);
tmp->set_line(*this);
return tmp;
}
// If the left expression is constant, then there are some
// special cases we can work with. If the left expression is
// not constant, but the right expression is constant, then
// there are some other interesting cases. But if neither are
// constant, then there is the general case.
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 > 0 && expr_wid > use_len)
use_len = expr_wid;
result = verinum(result, use_len);
}
tmp = new NetEConst(result);
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Precalculate " << *lpc << " << " << shift
<< " to constant " << *tmp
<< " (expr_wid=" << expr_wid << ")" << 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 if (NetEConst*rpc = dynamic_cast<NetEConst*> (rp)) {
long shift = rpc->value().as_long();
use_wid = lp->expr_width();
if (expr_wid > 0)
use_wid = expr_wid;
if (shift >= use_wid || (-shift) >= (long)lp->expr_width()) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Value left-shifted " << shift
<< " beyond width of " << use_wid
<< ". Elaborate as constant zero." << endl;
tmp = make_const_0(use_wid);
} else {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Left shift expression by constant "
<< shift << " bits. (use_wid=" << use_wid << ")" << endl;
lp = pad_to_width(lp, use_wid);
tmp = new NetEBShift(op_, lp, rp);
}
} else {
// Left side is not constant, so handle it the
// default way.
if (expr_wid >= 0)
lp = pad_to_width(lp, expr_wid);
tmp = new NetEBShift(op_, lp, rp);
}
tmp->set_line(*this);
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_rshift_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
NetExpr*tmp;
long use_wid = lp->expr_width();
if (expr_wid > 0)
use_wid = expr_wid;
if (use_wid == 0) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Oops, left expression width is not known, "
<< "so expression width is not known. Punt." << endl;
tmp = new NetEBShift(op_, lp, rp);
tmp->set_line(*this);
return tmp;
}
if (NetEConst*rpc = dynamic_cast<NetEConst*> (rp)) {
long shift = rpc->value().as_long();
// Detect the special cases that the shifted
// unsigned expression is completely shifted away to
// zero.
if ((op_=='r' || (lp->has_sign()==false))
&& shift >= (long)lp->expr_width()) {
// Special case that the value is unsigned
// shifted completely away.
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Value right-shifted " << shift
<< " beyond width of " << lp->expr_width()
<< ". Elaborate as constant zero." << endl;
tmp = make_const_0(use_wid);
tmp->set_line(*this);
return tmp;
}
if (shift >= (long)lp->expr_width()) {
// Signed right shift.
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Value signed-right-shifted " << shift
<< " beyond width of " << lp->expr_width()
<< ". Elaborate as replicated top bit." << endl;
ivl_assert(*this, lp->expr_width() > 0);
ivl_assert(*this, use_wid > 0);
tmp = new NetEConst(verinum(lp->expr_width()-1));
tmp->set_line(*this);
tmp = new NetESelect(lp, tmp, 1);
tmp->cast_signed(true);
tmp->set_line(*this);
tmp = pad_to_width(tmp, use_wid);
tmp->set_line(*this);
return tmp;
} else if (shift >= 0) {
// Signed right shift.
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Value signed-right-shifted " << shift
<< " beyond width of " << lp->expr_width()
<< "." << endl;
tmp = new NetEConst(verinum(shift));
tmp->set_line(*this);
long tmp_wid = lp->expr_width() - shift;
if (tmp_wid > use_wid)
tmp_wid = use_wid;
ivl_assert(*this, tmp_wid > 0);
ivl_assert(*this, use_wid > 0);
tmp = new NetESelect(lp, tmp, tmp_wid);
tmp->set_line(*this);
tmp->cast_signed(lp->has_sign() && op_=='R');
tmp = pad_to_width(tmp, use_wid);
tmp->set_line(*this);
return tmp;
} else if ((0-shift) >= use_wid) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Value signed-right-shifted " << shift
<< " beyond width of " << use_wid
<< "." << endl;
tmp = make_const_0(use_wid);
tmp->set_line(*this);
return tmp;
}
}
// Falback, handle the general case.
if (expr_wid > 0)
lp = pad_to_width(lp, expr_wid);
tmp = new NetEBShift(op_, lp, rp);
tmp->set_line(*this);
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_mult_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
// First, Make sure that signed arguments are padded to the
// width of the output. This is necessary for 2s complement
// multiplication to come out right.
if (expr_wid > 0) {
if (lp->has_sign() && lp->expr_type() != IVL_VT_REAL)
lp = pad_to_width(lp, expr_wid);
if (rp->has_sign() && rp->expr_type() != IVL_VT_REAL)
rp = pad_to_width(rp, expr_wid);
}
// Keep constants on the right side.
if (dynamic_cast<NetEConst*>(lp)) {
NetExpr*tmp = lp;
lp = rp;
rp = tmp;
}
// Handle a few special case multiplies against constants.
if (NetEConst*rp_const = dynamic_cast<NetEConst*> (rp)) {
verinum rp_val = rp_const->value();
int use_wid = expr_wid;
if (use_wid < 0)
use_wid = max(rp->expr_width(), lp->expr_width());
if (! rp_val.is_defined()) {
NetEConst*tmp = make_const_x(use_wid);
return tmp;
}
if (rp_val.is_zero()) {
NetEConst*tmp = make_const_0(use_wid);
return tmp;
}
}
// If this expression is unsigned, then make sure the
// arguments are unsigned so that the padding below doesn't
// cause any sign extension to happen.
suppress_binary_operand_sign_if_needed_(lp, rp);
// Multiply will guess a width that is the sum of the
// widths of the operand. If that sum is too small, then
// pad one of the arguments enough that the sum is the
// desired width.
if (expr_wid > (long)(lp->expr_width() + rp->expr_width()))
lp = pad_to_width(lp, expr_wid - rp->expr_width());
NetEBMult*tmp = new NetEBMult(op_, lp, rp);
tmp->set_line(*this);
if (expr_wid > 0)
tmp->set_width(expr_wid, false);
return tmp;
}
NetExpr* PEBinary::elaborate_expr_base_add_(Design*des,
NetExpr*lp, NetExpr*rp,
int expr_wid) const
{
NetExpr*tmp;
bool use_lossless_flag = expr_wid == -2;
// If this expression is not vectorable, then do NOT pass the
// lossless flag to the NetEBAdd constructor. For non-
// vectorable, lossless is implicit.
if (! type_is_vectorable(lp->expr_type()))
use_lossless_flag = false;
if (! type_is_vectorable(rp->expr_type()))
use_lossless_flag = false;
// If the expression is unsigned, then force the operands to
// unsigned so taht the set_width below doesn't cause them to
// be sign-extended.
suppress_binary_operand_sign_if_needed_(lp, rp);
tmp = new NetEBAdd(op_, lp, rp, use_lossless_flag);
if (expr_wid > 0 && type_is_vectorable(tmp->expr_type()))
tmp->set_width(expr_wid);
tmp->set_line(*this);
return tmp;
}
unsigned PEBComp::test_width(Design*, NetScope*,unsigned, unsigned,
ivl_variable_type_t&expr_type__,
bool&)
{
expr_type_ = IVL_VT_LOGIC;
expr_type__ = expr_type_;
expr_width_ = 1;
return 1;
}
NetExpr* PEBComp::elaborate_expr(Design*des, NetScope*scope,
int expr_width_dummy, bool sys_task_arg) const
{
assert(left_);
assert(right_);
bool unsized_flag = false;
ivl_variable_type_t left_type = IVL_VT_NO_TYPE;
unsigned left_width = left_->test_width(des, scope, 0, 0, left_type, unsized_flag);
bool save_flag = unsized_flag;
ivl_variable_type_t right_type = IVL_VT_NO_TYPE;
unsigned right_width = right_->test_width(des, scope, 0, 0, right_type, unsized_flag);
if (save_flag != unsized_flag)
left_width = left_->test_width(des, scope, 0, 0, left_type, 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_binary_operand_sign_if_needed_(lp, rp);
// The arguments of a compare need to have matching widths, so
// pad the width here. This matters because if the arguments
// are signed, then this padding will do sign extension.
if (type_is_vectorable(lp->expr_type()))
lp = pad_to_width(lp, use_wid);
if (type_is_vectorable(rp->expr_type()))
rp = pad_to_width(rp, use_wid);
eval_expr(lp, use_wid);
eval_expr(rp, use_wid);
// Handle some operand-specific special cases...
switch (op_) {
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;
}
break;
default:
break;
}
NetEBComp*tmp = new NetEBComp(op_, lp, rp);
tmp->set_line(*this);
bool flag = tmp->set_width(1);
if (flag == false) {
cerr << get_fileline() << ": internal error: "
"expression bit width of comparison != 1." << endl;
des->errors += 1;
}
return tmp;
}
unsigned PEBLogic::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type_out,
bool&unsized_flag)
{
expr_type_ = IVL_VT_LOGIC;
expr_width_ = 1;
expr_type_out = expr_type_;
return expr_width_;
}
NetExpr*PEBLogic::elaborate_expr(Design*des, NetScope*scope,
int expr_width_dummp, bool sys_task_arg) const
{
assert(left_);
assert(right_);
// The left and right expressions are self-determined and
// independent. Run their test_width methods independently. We
// don't need the widths here, but we do need the expressions
// to calculate their self-determined width and type.
bool left_flag = false;
ivl_variable_type_t left_type = IVL_VT_NO_TYPE;
left_->test_width(des, scope, 0, 0, left_type, left_flag);
bool right_flag = false;
ivl_variable_type_t right_type = IVL_VT_NO_TYPE;
right_->test_width(des, scope, 0, 0, right_type, right_flag);
NetExpr*lp = elab_and_eval(des, scope, left_, -1);
NetExpr*rp = elab_and_eval(des, scope, right_, -1);
if ((lp == 0) || (rp == 0)) {
delete lp;
delete rp;
return 0;
}
lp = condition_reduce(lp);
rp = condition_reduce(rp);
NetEBLogic*tmp = new NetEBLogic(op_, lp, rp);
tmp->set_line(*this);
tmp->set_width(1);
return tmp;
}
unsigned PEBShift::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
unsigned wid_left = left_->test_width(des,scope,min, 0, expr_type__, unsized_flag);
// The right expression is self-determined and has no impact
// on the expression size that is generated.
if (wid_left < min)
wid_left = min;
if (wid_left < lval)
wid_left = lval;
if (unsized_flag && wid_left < integer_width) {
wid_left = integer_width;
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Test width of unsized left shift"
<< " is padded to compiler integer width=" << wid_left
<< endl;
}
expr_type_ = expr_type__;
expr_width_ = wid_left;
// Run a test-width on the shift amount so that its types are
// worked out for elaboration later on. We don't need the
// value now.
ivl_variable_type_t rtype = IVL_VT_NO_TYPE;
bool rflag = false;
unsigned wid_right = right_->test_width(des, scope, 0, 0, rtype, rflag);
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Test width of shift amount of shift expression "
<< "returns wid=" << wid_right << ", type=" << rtype
<< ", flag=" << rflag << endl;
return expr_width_;
}
NetExpr*PEBShift::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool sys_task_arg) const
{
assert(left_);
assert(right_);
NetExpr*lp = left_->elaborate_expr(des, scope, expr_wid, false);
NetExpr*rp = right_->elaborate_expr(des, scope, -1, 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;
}
unsigned PECallFunction::test_width_sfunc_(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
perm_string name = peek_tail_name(path_);
if (name=="$signed"|| name=="$unsigned") {
PExpr*expr = parms_[0];
if (expr == 0)
return 0;
expr_width_ = expr->test_width(des, scope, min, lval, expr_type__, unsized_flag);
expr_type_ = expr_type__;
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width"
<< " of $signed/$unsigned returns test_width"
<< " of subexpression." << endl;
return expr_width_;
}
// Run through the arguments of the system function and make
// sure their widths/types are calculated. They are all self-
// determined.
for (unsigned idx = 0 ; idx < parms_.size() ; idx += 1) {
PExpr*expr = parms_[idx];
ivl_variable_type_t sub_type = IVL_VT_NO_TYPE;
bool flag = false;
unsigned wid = expr->test_width(des,scope,0,0,sub_type,flag);
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width"
<< " of " << name << " argument " << idx+1
<< " returns type=" << sub_type
<< ", wid=" << wid << endl;
}
if (name=="$sizeof" || name=="$bits") {
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width"
<< " of $sizeof/$bits returns test_width"
<< " of compiler integer." << endl;
expr_type_ = IVL_VT_BOOL;
expr_width_= integer_width;
expr_type__ = expr_type_;
return expr_width_;
}
if (name=="$is_signed") {
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width"
<< " of $is_signed returns test_width"
<< " of 1." << endl;
expr_type_ = IVL_VT_BOOL;
expr_width_ = 1;
expr_type__ = expr_type_;
return expr_width_;
}
/* Get the return type of the system function by looking it up
in the sfunc_table. */
const struct sfunc_return_type*sfunc_info
= lookup_sys_func(peek_tail_name(path_));
expr_type_ = sfunc_info->type;
expr_width_ = sfunc_info->wid;
expr_type__ = expr_type_;
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width "
<< "of system function " << name
<< " returns wid=" << expr_width_
<< ", type=" << expr_type_ << "." << endl;
return expr_width_;
}
unsigned PECallFunction::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
if (peek_tail_name(path_)[0] == '$')
return test_width_sfunc_(des, scope, min, lval, expr_type__, unsized_flag);
// The width of user defined functions depends only on the
// width of the return value. The arguments are entirely
// self-determined.
NetFuncDef*def = des->find_function(scope, path_);
if (def == 0) {
// If this is an access function, then the width and
// type are known by definition.
if (find_access_function(path_)) {
expr_type_ = IVL_VT_REAL;
expr_width_ = 1;
expr_type__ = expr_type_;
return expr_width_;
}
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())) {
expr_type_ = res->data_type();
if (debug_elaborate)
cerr << get_fileline() << ": debug: test_width "
<< "of function returns width " << res->vector_width()
<< ", type=" << expr_type_
<< "." << endl;
if (! type_is_vectorable(expr_type__))
unsized_flag = true;
expr_width_ = res->vector_width();
expr_type__ = expr_type_;
return expr_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_.size() != 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_.size() != 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_.size() != 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 ( (uint64_t)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_.size() != 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_.size();
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_access_func_(Design*des, NetScope*scope,
ivl_nature_t nature) const
{
// An access function must have 1 or 2 arguments.
ivl_assert(*this, parms_.size()==2 || parms_.size()==1);
NetBranch*branch = 0;
if (parms_.size() == 1) {
PExpr*arg1 = parms_[0];
PEIdent*arg_ident = dynamic_cast<PEIdent*> (arg1);
ivl_assert(*this, arg_ident);
const pform_name_t&path = arg_ident->path();
ivl_assert(*this, path.size()==1);
perm_string name = peek_tail_name(path);
NetNet*sig = scope->find_signal(name);
ivl_assert(*this, sig);
ivl_discipline_t dis = sig->get_discipline();
ivl_assert(*this, dis);
ivl_assert(*this, nature == dis->potential() || nature == dis->flow());
branch = new NetBranch(dis);
branch->set_line(*this);
connect(branch->pin(0), sig->pin(0));
NetNet*gnd = des->find_discipline_reference(dis, scope);
connect(branch->pin(1), gnd->pin(0));
des->add_branch(branch);
join_island(branch);
} else {
ivl_assert(*this, 0);
}
NetEAccess*tmp = new NetEAccess(branch, nature);
tmp->set_line(*this);
return tmp;
}
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) {
// Not a user defined function. Maybe it is an access
// function for a nature? If so then elaborate it that
// way.
ivl_nature_t access_nature = find_access_function(path_);
if (access_nature)
return elaborate_access_func_(des, scope, access_nature);
cerr << get_fileline() << ": error: No function " << path_ <<
" in this context (" << scope_path(scope) << ")." << endl;
des->errors += 1;
return 0;
}
ivl_assert(*this, def);
NetScope*dscope = def->scope();
ivl_assert(*this, dscope);
if (! check_call_matches_definition_(des, dscope))
return 0;
unsigned parms_count = parms_.size();
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) {
parms[idx] = elaborate_rval_expr(des, scope,
def->port(idx)->data_type(),
def->port(idx)->vector_width(),
tmp);
if (debug_elaborate)
cerr << get_fileline() << ": debug:"
<< " function " << path_
<< " arg " << (idx+1)
<< " argwid=" << parms[idx]->expr_width()
<< ": " << *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;
}
unsigned PEConcat::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
expr_type_ = IVL_VT_LOGIC;
if (debug_elaborate)
cerr << get_fileline() << ": debug: CONCAT MISSING TEST_WIDTH!" << endl;
expr_type__ = expr_type_;
unsized_flag = false;
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_defined()) {
cerr << get_fileline() << ": error: Concatenation repeat "
<< "may not be undefined (" << rep->value()
<< ")." << endl;
des->errors += 1;
concat_depth -= 1;
return 0;
}
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;
}
/*
* Floating point literals are not vectorable. It's not particularly
* clear what to do about an actual width to return, but whatever the
* width, it is unsigned.
*
* Absent any better idea, we call all real valued results a width of 1.
*/
unsigned PEFNumber::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
expr_type_ = IVL_VT_REAL;
expr_width_ = 1;
unsized_flag = true;
expr_type__ = expr_type_;
return 1;
}
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);
ivl_variable_type_t tmp_type = IVL_VT_NO_TYPE;
bool tmp_flag = false;
int msb_wid = index_tail.msb->test_width(des, scope, 0, 0, tmp_type, tmp_flag);
tmp_type = IVL_VT_NO_TYPE;
tmp_flag = false;
int lsb_wid = index_tail.lsb->test_width(des, scope, 0, 0, tmp_type, tmp_flag);
/* 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, lsb_wid);
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;
/* Attempt to recover from error. */
lsb = 0;
} else {
lsb = lsb_c->value().as_long();
}
NetExpr*msb_ex = elab_and_eval(des, scope, index_tail.msb, msb_wid);
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;
/* Attempt to recover from error. */
msb = lsb;
} else {
msb = msb_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;
}
/*
* When we know that this is an indexed part select (up or down) this
* method calculates the up/down base, as far at it can be calculated.
*/
NetExpr* PEIdent::calculate_up_do_base_(Design*des, NetScope*scope) 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 != 0);
ivl_assert(*this, index_tail.msb != 0);
NetExpr*tmp = elab_and_eval(des, scope, index_tail.msb, -1);
return tmp;
}
bool PEIdent::calculate_param_range_(Design*des, NetScope*scope,
const NetExpr*par_msb, long&par_msv,
const NetExpr*par_lsb, long&par_lsv) const
{
if (par_msb == 0) {
// If the parameter doesn't have an explicit range, then
// just return range values of 0:0. The par_msv==0 is
// correct. The par_msv is not necessarily correct, but
// clients of this function don't need a correct value.
ivl_assert(*this, par_lsb == 0);
par_msv = 0;
par_lsv = 0;
return true;
}
const NetEConst*tmp = dynamic_cast<const NetEConst*> (par_msb);
ivl_assert(*this, tmp);
par_msv = tmp->value().as_long();
tmp = dynamic_cast<const NetEConst*> (par_lsb);
ivl_assert(*this, tmp);
par_lsv = tmp->value().as_long();
return true;
}
unsigned PEIdent::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
NetNet* net = 0;
const NetExpr*par = 0;
NetEvent* eve = 0;
const NetExpr*ex1, *ex2;
symbol_search(0, des, scope, path_, net, par, eve, ex1, ex2);
// If there is a part/bit select expression, then process it
// here. This constrains the results no matter what kind the
// name is.
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()) {
const index_component_t&index_tail = name_tail.index.back();
use_sel = index_tail.sel;
}
unsigned use_width = UINT_MAX;
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);
}
if (use_width != UINT_MAX) {
expr_type_ = IVL_VT_LOGIC; // Assume bit/parts selects are logic
expr_width_ = max(use_width, min);
expr_type__ = expr_type_;
return expr_width_;
}
// The width of a signal expression is the width of the signal.
if (net != 0) {
expr_type_ = net->data_type();
expr_width_= max(net->vector_width(), (unsigned long)min);
expr_type__ = expr_type_;
return expr_width_;
}
// The width of a parameter name is the width of the range for
// the parameter name, if a range is declared. Otherwise, the
// width is undefined.
if (par != 0) {
expr_type_ = par->expr_type();
expr_type__ = expr_type_;
if (ex1) {
ivl_assert(*this, ex2);
const NetEConst*ex1_const = dynamic_cast<const NetEConst*> (ex1);
const NetEConst*ex2_const = dynamic_cast<const NetEConst*> (ex2);
ivl_assert(*this, ex1_const && ex2_const);
long msb = ex1_const->value().as_long();
long lsb = ex2_const->value().as_long();
if (msb >= lsb)
expr_width_ = msb - lsb + 1;
else
expr_width_ = lsb - msb + 1;
return expr_width_;
}
// This is a parameter. If it is sized (meaning it was
// declared with range expressions) then the range
// expressions would have been caught above. So if we
// got there there we know this is an unsized constant.
expr_width_ = par->expr_width();
unsized_flag = true;
return expr_width_;
}
// Not a net, and not a parameter? Give up on the type, but
// set the width that we collected.
expr_type_ = IVL_VT_NO_TYPE;
expr_width_ = min;
expr_type__ = expr_type_;
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(this, 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, expr_wid);
// 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:
tmp = new NetECReal(verireal(value.real_val));
break;
default:
break;
}
assert(tmp);
tmp->set_line(*this);
if (debug_elaborate)
cerr << get_fileline() << ": debug: " << path_
<< " is a specparam" << endl;
return tmp;
}
}
if (error_implicit==false
&& sys_task_arg==false
&& path_.size()==1
&& scope->default_nettype() != NetNet::NONE) {
NetNet::Type nettype = scope->default_nettype();
net = new NetNet(scope, peek_tail_name(path_), nettype, 1);
net->data_type(IVL_VT_LOGIC);
net->set_line(*this);
if (warn_implicit) {
cerr << get_fileline() << ": warning: implicit "
"definition of wire " << scope_path(scope)
<< "." << peek_tail_name(path_) << "." << endl;
}
return elaborate_expr_net(des, scope, net, scope, sys_task_arg);
}
// At this point we've exhausted all the possibilities that
// are not scopes. If this is not a system task argument, then
// it cannot be a scope name, so give up.
if (! sys_task_arg) {
// I cannot interpret this identifier. Error message.
cerr << get_fileline() << ": error: Unable to bind wire/reg/memory "
"`" << path_ << "' in `" << scope_path(scope) << "'" << endl;
des->errors += 1;
return 0;
}
// Finally, if this is a scope name, then return that. Look
// first to see if this is a name of a local scope. Failing
// that, search globally for a hierarchical name.
if ((path_.size() == 1)) {
hname_t use_name ( peek_tail_name(path_) );
if (NetScope*nsc = scope->child(use_name)) {
NetEScope*tmp = new NetEScope(nsc);
tmp->set_line(*this);
if (debug_elaborate)
cerr << get_fileline() << ": debug: Found scope "
<< use_name << " in scope " << scope->basename()
<< endl;
return tmp;
}
}
list<hname_t> spath = eval_scope_path(des, scope, path_);
ivl_assert(*this, spath.size() == path_.size());
// Try full hierarchical scope name.
if (NetScope*nsc = des->find_scope(spath)) {
NetEScope*tmp = new NetEScope(nsc);
tmp->set_line(*this);
if (debug_elaborate)
cerr << get_fileline() << ": debug: Found scope "
<< nsc->basename()
<< " path=" << path_ << endl;
if (! sys_task_arg) {
cerr << get_fileline() << ": error: Scope name "
<< nsc->basename() << " not allowed here." << endl;
des->errors += 1;
}
return tmp;
}
// Try relative scope name.
if (NetScope*nsc = des->find_scope(scope, spath)) {
NetEScope*tmp = new NetEScope(nsc);
tmp->set_line(*this);
if (debug_elaborate)
cerr << get_fileline() << ": debug: Found scope "
<< nsc->basename() << " in " << scope_path(scope) << endl;
return tmp;
}
// I cannot interpret this identifier. Error message.
cerr << get_fileline() << ": error: Unable to bind wire/reg/memory "
"`" << path_ << "' in `" << scope_path(scope) << "'" << endl;
des->errors += 1;
return 0;
}
static verinum param_part_select_bits(const verinum&par_val, long wid,
long lsv, long par_lsv)
{
verinum result (verinum::Vx, wid, true);
for (long idx = 0 ; idx < wid ; idx += 1) {
long off = idx + lsv - par_lsv;
if (off < 0)
result.set(idx, verinum::Vx);
else if (off < (long)par_val.len())
result.set(idx, par_val.get(off));
else if (par_val.is_string()) // Pad strings with nulls.
result.set(idx, verinum::V0);
else if (par_val.has_len()) // Pad sized parameters with X
result.set(idx, verinum::Vx);
else // Unsized parameters are "infinite" width.
result.set(idx, sign_bit(par_val));
}
// If the input is a string, and the part select is working on
// byte boundaries, then make the result into a string.
if (par_val.is_string() && (labs(lsv-par_lsv)%8 == 0) && (wid%8 == 0))
return result.as_string();
return result;
}
NetExpr* PEIdent::elaborate_expr_param_part_(Design*des, NetScope*scope,
const NetExpr*par,
NetScope*found_in,
const NetExpr*par_msb,
const NetExpr*par_lsb) const
{
long msv, lsv;
bool flag = calculate_parts_(des, scope, msv, lsv);
if (!flag)
return 0;
long par_msv, par_lsv;
flag = calculate_param_range_(des, scope, par_msb, par_msv, par_lsb, par_lsv);
if (!flag)
return 0;
// Notice that the par_msv is not used in this function other
// than for this test. It is used to tell the direction that
// the bits are numbers, so that we can make sure the
// direction matches the part select direction. After that,
// we only need the par_lsv.
if ((msv>lsv && par_msv<par_lsv) || (msv<lsv && par_msv>=par_lsv)) {
cerr << get_fileline() << ": error: Part select "
<< "[" << msv << ":" << lsv << "] is out of order." << endl;
des->errors += 1;
return 0;
}
long wid = 1 + labs(msv-lsv);
if (debug_elaborate)
cerr << get_fileline() << ": debug: Calculate part select "
<< "[" << msv << ":" << lsv << "] from range "
<< "[" << par_msv << ":" << par_lsv << "]." << endl;
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
verinum result = param_part_select_bits(par_ex->value(), wid, lsv, par_lsv);
NetEConst*result_ex = new NetEConst(result);
result_ex->set_line(*this);
return result_ex;
}
NetExpr* PEIdent::elaborate_expr_param_idx_up_(Design*des, NetScope*scope,
const NetExpr*par,
NetScope*found_in,
const NetExpr*par_msb,
const NetExpr*par_lsb) const
{
long par_msv, par_lsv;
bool flag = calculate_param_range_(des, scope, par_msb, par_msv, par_lsb, par_lsv);
if (!flag)
return 0;
NetExpr*base = calculate_up_do_base_(des, scope);
if (base == 0)
return 0;
unsigned long wid = 0;
calculate_up_do_width_(des, scope, wid);
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
if (debug_elaborate)
cerr << get_fileline() << ": debug: Calculate part select "
<< "[" << *base << "+:" << wid << "] from range "
<< "[" << par_msv << ":" << par_lsv << "]." << endl;
// Handle the special case that the base is constant. In this
// case, just precalculate the entire constant result.
if (NetEConst*base_c = dynamic_cast<NetEConst*> (base)) {
long lsv = base_c->value().as_long();
// Watch out for reversed bit numbering. We're making
// the part select from LSB to MSB.
if (par_msv < par_lsv)
lsv = lsv - wid + 1;
verinum result = param_part_select_bits(par_ex->value(), wid,
lsv, par_lsv);
NetEConst*result_ex = new NetEConst(result);
result_ex->set_line(*this);
return result_ex;
}
if ((par_msb < par_lsb) && (wid>1))
base = make_add_expr(base, 1-(long)wid);
NetExpr*tmp = par->dup_expr();
tmp = new NetESelect(tmp, base, wid);
tmp->set_line(*this);
return tmp;
}
/*
* Handle the case that the identifier is a parameter reference. The
* parameter expression has already been located for us (as the par
* argument) so we just need to process the sub-expression.
*/
NetExpr* PEIdent::elaborate_expr_param_(Design*des,
NetScope*scope,
const NetExpr*par,
NetScope*found_in,
const NetExpr*par_msb,
const NetExpr*par_lsb,
int expr_wid) const
{
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;
// NOTE TO SELF: This is the way I want to see this code
// structured. This closely follows the structure of the
// elaborate_expr_net_ code, which splits all the various
// selects to different methods.
if (use_sel == index_component_t::SEL_PART)
return elaborate_expr_param_part_(des, scope, par, found_in,
par_msb, par_lsb);
if (use_sel == index_component_t::SEL_IDX_UP)
return elaborate_expr_param_idx_up_(des, scope, par, found_in,
par_msb, par_lsb);
// NOTE TO SELF (continued): The code below should be
// rewritten in the above format, as I get to it.
NetExpr*tmp = par->dup_expr();
if (use_sel == index_component_t::SEL_IDX_DO) {
ivl_assert(*this, !name_tail.index.empty());
const index_component_t&index_tail = name_tail.index.back();
ivl_assert(*this, index_tail.msb);
ivl_assert(*this, index_tail.lsb);
/* Get and evaluate the width of the index
select. This must be constant. */
NetExpr*wid_ex = elab_and_eval(des, scope, index_tail.lsb, -1);
NetEConst*wid_ec = dynamic_cast<NetEConst*> (wid_ex);
if (wid_ec == 0) {
cerr << index_tail.lsb->get_fileline() << ": error: "
<< "Second expression of indexed part select "
<< "most be constant." << endl;
des->errors += 1;
return 0;
}
unsigned wid = wid_ec->value().as_ulong();
NetExpr*idx_ex = elab_and_eval(des, scope, index_tail.msb, -1);
if (idx_ex == 0) {
return 0;
}
if (use_sel == index_component_t::SEL_IDX_DO && wid > 1) {
idx_ex = make_add_expr(idx_ex, 1-(long)wid);
}
/* Wrap the param expression with a part select. */
tmp = new NetESelect(tmp, idx_ex, wid);
} else if (use_sel == index_component_t::SEL_BIT) {
ivl_assert(*this, !name_tail.index.empty());
const index_component_t&index_tail = name_tail.index.back();
ivl_assert(*this, index_tail.msb);
ivl_assert(*this, !index_tail.lsb);
const NetEConst*par_me =dynamic_cast<const NetEConst*>(par_msb);
const NetEConst*par_le =dynamic_cast<const NetEConst*>(par_lsb);
ivl_assert(*this, par_me || !par_msb);
ivl_assert(*this, par_le || !par_lsb);
ivl_assert(*this, par_me || !par_le);
/* Handle the case where a parameter has a bit
select attached to it. Generate a NetESelect
object to select the bit as desired. */
NetExpr*mtmp = index_tail.msb->elaborate_expr(des, scope, -1,false);
eval_expr(mtmp);
/* Let's first try to get constant values for both
the parameter and the bit select. If they are
both constant, then evaluate the bit select and
return instead a single-bit constant. */
NetEConst*le = dynamic_cast<NetEConst*>(tmp);
NetEConst*re = dynamic_cast<NetEConst*>(mtmp);
if (le && re) {
/* Argument and bit select are constant. Calculate
the final result. */
verinum lv = le->value();
verinum rv = re->value();
verinum::V rb = verinum::Vx;
long par_mv = lv.len()-1;
long par_lv = 0;
if (par_me) {
par_mv = par_me->value().as_long();
par_lv = par_le->value().as_long();
}
/* Convert the index to canonical bit address. */
long ridx = rv.as_long();
if (par_mv >= par_lv) {
ridx -= par_lv;
} else {
ridx = par_mv - ridx + par_lv;
}
if ((ridx >= 0) && ((unsigned long) ridx < lv.len())) {
rb = lv[ridx];
} else if ((ridx >= 0) && (!lv.has_len())) {
if (lv.has_sign())
rb = lv[lv.len()-1];
else
rb = verinum::V0;
}
NetEConst*re2 = new NetEConst(verinum(rb, 1));
delete tmp;
delete mtmp;
tmp = re2;
} else {
if (par_me) {
long par_mv = par_me->value().as_long();
long par_lv = par_le->value().as_long();
if (par_mv >= par_lv) {
mtmp = par_lv
? make_add_expr(mtmp, 0-par_lv)
: mtmp;
} else {
if (par_lv != 0)
mtmp = make_add_expr(mtmp, 0-par_mv);
mtmp = make_sub_expr(par_lv-par_mv, mtmp);
}
}
/* The value is constant, but the bit select
expression is not. Elaborate a NetESelect to
evaluate the select at run-time. */
NetESelect*stmp = new NetESelect(tmp, mtmp, 1);
tmp->set_line(*this);
tmp = stmp;
}
} else {
/* No bit or part select. Make the constant into a
NetEConstParam if possible. */
NetEConst*ctmp = dynamic_cast<NetEConst*>(tmp);
if (ctmp != 0) {
perm_string name = peek_tail_name(path_);
NetEConstParam*ptmp
= new NetEConstParam(found_in, name, ctmp->value());
if (expr_wid > 0)
ptmp->set_width((unsigned)expr_wid);
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Elaborate parameter <" << name
<< "> as constant " << *ptmp << endl;
delete tmp;
tmp = ptmp;
}
}
tmp->set_line(*this);
return tmp;
}
/*
* Handle word selects of vector arrays.
*/
NetExpr* PEIdent::elaborate_expr_net_word_(Design*des, NetScope*scope,
NetNet*net, NetScope*found_in,
bool sys_task_arg) const
{
const name_component_t&name_tail = path_.back();
if (name_tail.index.empty() && !sys_task_arg) {
cerr << get_fileline() << ": error: Array " << path()
<< " Needs an array index here." << endl;
des->errors += 1;
return 0;
}
index_component_t index_front;
if (! name_tail.index.empty()) {
index_front = name_tail.index.front();
ivl_assert(*this, index_front.sel != index_component_t::SEL_NONE);
if (index_front.sel != index_component_t::SEL_BIT) {
cerr << get_fileline() << ": error: Array " << path_
<< " cannot be indexed by a range." << endl;
des->errors += 1;
return 0;
}
ivl_assert(*this, index_front.msb);
ivl_assert(*this, !index_front.lsb);
}
NetExpr*word_index = index_front.sel == index_component_t::SEL_NONE
? 0
: elab_and_eval(des, scope, index_front.msb, -1);
if (word_index == 0 && !sys_task_arg)
return 0;
if (NetEConst*word_addr = dynamic_cast<NetEConst*>(word_index)) {
long addr = word_addr->value().as_long();
// Special case: The index is out of range, so the value
// of this expression is a 'bx vector the width of a word.
if (!net->array_index_is_valid(addr)) {
NetEConst*resx = make_const_x(net->vector_width());
resx->set_line(*this);
delete word_index;
return resx;
}
// Recalculate the constant address with the adjusted base.
unsigned use_addr = net->array_index_to_address(addr);
if (addr < 0 || use_addr != (unsigned long)addr) {
verinum val ( (uint64_t)use_addr, 8*sizeof(use_addr));
NetEConst*tmp = new NetEConst(val);
tmp->set_line(*this);
delete word_index;
word_index = tmp;
}
} else if (word_index) {
// If there is a non-zero base to the memory, then build an
// expression to calculate the canonical address.
if (long base = net->array_first()) {
word_index = make_add_expr(word_index, 0-base);
eval_expr(word_index);
}
}
NetESignal*res = new NetESignal(net, word_index);
res->set_line(*this);
// Detect that the word has a bit/part select as well.
index_component_t::ctype_t word_sel = index_component_t::SEL_NONE;
if (name_tail.index.size() > 1)
word_sel = name_tail.index.back().sel;
if (word_sel == index_component_t::SEL_PART)
return elaborate_expr_net_part_(des, scope, res, found_in);
if (word_sel == index_component_t::SEL_IDX_UP)
return elaborate_expr_net_idx_up_(des, scope, res, found_in);
if (word_sel == index_component_t::SEL_IDX_DO)
return elaborate_expr_net_idx_do_(des, scope, res, found_in);
if (word_sel == index_component_t::SEL_BIT)
return elaborate_expr_net_bit_(des, scope, res, found_in);
ivl_assert(*this, word_sel == index_component_t::SEL_NONE);
return res;
}
/*
* Handle part selects of NetNet identifiers.
*/
NetExpr* PEIdent::elaborate_expr_net_part_(Design*des, NetScope*scope,
NetESignal*net, NetScope*found_in) const
{
long msv, lsv;
bool flag = calculate_parts_(des, scope, msv, lsv);
if (!flag)
return 0;
/* The indices of part selects are signed integers, so allow
negative values. However, the width that they represent is
unsigned. Remember that any order is possible,
i.e., [1:0], [-4:6], etc. */
unsigned long wid = 1 + labs(msv-lsv);
if (net->sig()->sb_to_idx(msv) < net->sig()->sb_to_idx(lsv)) {
cerr << get_fileline() << ": error: part select ["
<< msv << ":" << lsv << "] out of order." << endl;
des->errors += 1;
//delete lsn;
//delete msn;
return net;
}
long sb_lsb = net->sig()->sb_to_idx(lsv);
long sb_msb = net->sig()->sb_to_idx(msv);
// If the part select covers exactly the entire
// vector, then do not bother with it. Return the
// signal itself, casting to unsigned if necessary.
if (sb_lsb == 0 && wid == net->vector_width()) {
net->cast_signed(false);
return net;
}
// If the part select covers NONE of the vector, then return a
// constant X.
if ((sb_lsb >= (signed) net->vector_width()) || (sb_msb < 0)) {
NetEConst*tmp = make_const_x(wid);
tmp->set_line(*this);
return tmp;
}
NetExpr*ex = new NetEConst(verinum(sb_lsb));
NetESelect*ss = new NetESelect(net, ex, wid);
ss->set_line(*this);
return ss;
}
/*
* Part select indexed up, i.e. net[<m> +: <l>]
*/
NetExpr* PEIdent::elaborate_expr_net_idx_up_(Design*des, NetScope*scope,
NetESignal*net, NetScope*found_in) const
{
NetExpr*base = calculate_up_do_base_(des, scope);
unsigned long wid = 0;
calculate_up_do_width_(des, scope, wid);
// Handle the special case that the base is constant as
// well. In this case it can be converted to a conventional
// part select.
if (NetEConst*base_c = dynamic_cast<NetEConst*> (base)) {
long lsv = base_c->value().as_long();
// If the part select covers exactly the entire
// vector, then do not bother with it. Return the
// signal itself.
if (net->sig()->sb_to_idx(lsv) == 0 && wid == net->vector_width())
return net;
// Otherwise, make a part select that covers the right range.
NetExpr*ex = new NetEConst(verinum(net->sig()->sb_to_idx(lsv)));
NetESelect*ss = new NetESelect(net, ex, wid);
ss->set_line(*this);
delete base;
return ss;
}
if (net->msi() > net->lsi()) {
if (long offset = net->lsi())
base = make_add_expr(base, 0-offset);
} else {
long vwid = net->lsi() - net->msi() + 1;
long offset = net->msi();
base = make_sub_expr(vwid-offset-wid, base);
}
NetESelect*ss = new NetESelect(net, base, wid);
ss->set_line(*this);
if (debug_elaborate) {
cerr << get_fileline() << ": debug: Elaborate part "
<< "select base="<< *base << ", wid="<< wid << endl;
}
return ss;
}
/*
* Part select indexed down, i.e. net[<m> -: <l>]
*/
NetExpr* PEIdent::elaborate_expr_net_idx_do_(Design*des, NetScope*scope,
NetESignal*net, NetScope*found_in)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 != 0);
ivl_assert(*this, index_tail.msb != 0);
NetExpr*base = elab_and_eval(des, scope, index_tail.msb, -1);
unsigned long wid = 0;
calculate_up_do_width_(des, scope, wid);
// Handle the special case that the base is constant as
// well. In this case it can be converted to a conventional
// part select.
if (NetEConst*base_c = dynamic_cast<NetEConst*> (base)) {
long lsv = base_c->value().as_long();
// If the part select covers exactly the entire
// vector, then do not bother with it. Return the
// signal itself.
if (net->sig()->sb_to_idx(lsv) == (signed) (wid-1) &&
wid == net->vector_width())
return net;
// Otherwise, make a part select that covers the right range.
NetExpr*ex = new NetEConst(verinum(net->sig()->sb_to_idx(lsv)-wid+1));
NetESelect*ss = new NetESelect(net, ex, wid);
ss->set_line(*this);
delete base;
return ss;
}
long offset = net->lsi();
NetExpr*base_adjusted = wid > 1
? make_add_expr(base,1-(long)wid-offset)
: (offset == 0? base : make_add_expr(base, 0-offset));
NetESelect*ss = new NetESelect(net, base_adjusted, wid);
ss->set_line(*this);
if (debug_elaborate) {
cerr << get_fileline() << ": debug: Elaborate part "
<< "select base="<< *base_adjusted << ", wid="<< wid << endl;
}
return ss;
}
NetExpr* PEIdent::elaborate_expr_net_bit_(Design*des, NetScope*scope,
NetESignal*net, NetScope*found_in) 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.msb != 0);
ivl_assert(*this, index_tail.lsb == 0);
NetExpr*ex = elab_and_eval(des, scope, index_tail.msb, -1);
// If the bit select is constant, then treat it similar
// to the part select, so that I save the effort of
// making a mux part in the netlist.
if (NetEConst*msc = dynamic_cast<NetEConst*> (ex)) {
long msv = msc->value().as_long();
unsigned idx = net->sig()->sb_to_idx(msv);
if (idx >= net->vector_width()) {
/* The bit select is out of range of the
vector. This is legal, but returns a
constant 1'bx value. */
NetEConst*tmp = make_const_x(1);
tmp->set_line(*this);
cerr << get_fileline() << ": warning: Bit select ["
<< msv << "] out of range of vector "
<< net->name() << "[" << net->sig()->msb()
<< ":" << net->sig()->lsb() << "]." << endl;
cerr << get_fileline() << ": : Replacing "
<< "expression with a constant 1'bx." << endl;
delete ex;
return tmp;
}
// If the vector is only one bit, we are done. The
// bit select will return the scalar itself.
if (net->vector_width() == 1)
return net;
// Make an expression out of the index
NetEConst*idx_c = new NetEConst(verinum(idx));
idx_c->set_line(*net);
// Make a bit select with the canonical index
NetESelect*res = new NetESelect(net, idx_c, 1);
res->set_line(*net);
return res;
}
// Non-constant bit select? punt and make a subsignal
// device to mux the bit in the net. This is a fairly
// complicated task because we need to generate
// expressions to convert calculated bit select
// values to canonical values that are used internally.
if (net->sig()->msb() < net->sig()->lsb()) {
ex = make_sub_expr(net->sig()->lsb(), ex);
} else {
ex = make_add_expr(ex, - net->sig()->lsb());
}
NetESelect*ss = new NetESelect(net, ex, 1);
ss->set_line(*this);
return ss;
}
NetExpr* PEIdent::elaborate_expr_net(Design*des, NetScope*scope,
NetNet*net, NetScope*found_in,
bool sys_task_arg) const
{
if (net->array_dimensions() > 0)
return elaborate_expr_net_word_(des, scope, net, found_in, sys_task_arg);
NetESignal*node = new NetESignal(net);
node->set_line(*this);
index_component_t::ctype_t use_sel = index_component_t::SEL_NONE;
if (! path_.back().index.empty())
use_sel = path_.back().index.back().sel;
// If this is a part select of a signal, then make a new
// temporary signal that is connected to just the
// selected bits. The lsb_ and msb_ expressions are from
// the foo[msb:lsb] expression in the original.
if (use_sel == index_component_t::SEL_PART)
return elaborate_expr_net_part_(des, scope, node, found_in);
if (use_sel == index_component_t::SEL_IDX_UP)
return elaborate_expr_net_idx_up_(des, scope, node, found_in);
if (use_sel == index_component_t::SEL_IDX_DO)
return elaborate_expr_net_idx_do_(des, scope, node, found_in);
if (use_sel == index_component_t::SEL_BIT)
return elaborate_expr_net_bit_(des, scope, node, found_in);
// It's not anything else, so this must be a simple identifier
// expression with no part or bit select. Return the signal
// itself as the expression.
assert(use_sel == index_component_t::SEL_NONE);
return node;
}
unsigned PENumber::test_width(Design*, NetScope*,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
expr_type_ = IVL_VT_LOGIC;
unsigned use_wid = value_->len();
if (min > use_wid)
use_wid = min;
if (! value_->has_len())
unsized_flag = true;
if (lval > 0 && lval < use_wid)
use_wid = lval;
expr_type__ = expr_type_;
expr_width_ = use_wid;
return use_wid;
}
NetEConst* PENumber::elaborate_expr(Design*des, NetScope*,
int expr_width__, bool) const
{
assert(value_);
verinum tvalue = *value_;
// If the expr_width is >0, then the context is requesting a
// specific size (for example this is part of the r-values of
// an assignment) so we pad to the desired width and ignore
// the self-determined size.
if (expr_width__ > 0) {
tvalue = pad_to_width(tvalue, expr_width__);
if (tvalue.len() > (unsigned)expr_width__) {
verinum tmp (tvalue, expr_width__);
tmp.has_sign(tvalue.has_sign());
tvalue = tmp;
}
}
NetEConst*tmp = new NetEConst(tvalue);
tmp->set_line(*this);
return tmp;
}
unsigned PEString::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
expr_type_ = IVL_VT_BOOL;
expr_width_ = text_? 8*strlen(text_) : 0;
if (min > expr_width_)
expr_width_ = min;
expr_type__ = expr_type_;
return expr_width_;
}
NetEConst* PEString::elaborate_expr(Design*des, NetScope*,
int expr_width_dummy, bool) const
{
NetEConst*tmp = new NetEConst(value());
tmp->set_line(*this);
return tmp;
}
unsigned PETernary::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&flag)
{
// The condition of the ternary is self-determined, but we
// test its width to force its type to be calculated.
ivl_variable_type_t con_type = IVL_VT_NO_TYPE;
bool con_flag = false;
expr_->test_width(des, scope, 0, 0, con_type, con_flag);
ivl_variable_type_t tru_type = IVL_VT_NO_TYPE;
unsigned tru_wid = tru_->test_width(des, scope, min, lval, tru_type,flag);
bool initial_flag = flag;
ivl_variable_type_t fal_type = IVL_VT_NO_TYPE;
unsigned fal_wid = fal_->test_width(des, scope, min, lval, fal_type,flag);
// If the false clause is unsized, then try again with the
// true clause, because it might choose a different width if
// it is in an unsized context.
if (initial_flag == false && flag == true) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "False clause is unsized, so retest width of true clause."
<< endl;
tru_wid = tru_->test_width(des, scope, max(min,fal_wid), lval, tru_type, flag);
}
if (tru_type == IVL_VT_REAL || fal_type == IVL_VT_REAL)
expr_type_ = IVL_VT_REAL;
else if (tru_type == IVL_VT_LOGIC || fal_type == IVL_VT_LOGIC)
expr_type_ = IVL_VT_LOGIC;
else
expr_type_ = tru_type;
expr_width_ = max(tru_wid,fal_wid);
expr_type__ = expr_type_;
return expr_width_;
}
bool NetETernary::test_operand_compat(ivl_variable_type_t l,
ivl_variable_type_t r)
{
if (l == IVL_VT_LOGIC && r == IVL_VT_BOOL)
return true;
if (l == IVL_VT_BOOL && r == IVL_VT_LOGIC)
return true;
if (l == IVL_VT_REAL && (r == IVL_VT_LOGIC || r == IVL_VT_BOOL))
return true;
if (r == IVL_VT_REAL && (l == IVL_VT_LOGIC || l == IVL_VT_BOOL))
return true;
if (l == r)
return true;
return false;
}
/*
* Elaborate the Ternary operator. I know that the expressions were
* parsed so I can presume that they exist, and call elaboration
* methods. If any elaboration fails, then give up and return 0.
*/
NetExpr*PETernary::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool) const
{
assert(expr_);
assert(tru_);
assert(fal_);
int use_wid = expr_wid >= 0? expr_wid : 0;
if (expr_wid < 0) {
use_wid = expr_width();
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Self-sized ternary chooses wid="<< use_wid
<< ", type=" << expr_type()
<< ", expr=" << *this
<< endl;
ivl_assert(*this, use_wid > 0);
}
// Elaborate and evaluate the condition expression. Note that
// it is always self-determined.
NetExpr*con = elab_and_eval(des, scope, expr_, -1);
if (con == 0)
return 0;
/* Make sure the condition expression reduces to a single bit. */
con = condition_reduce(con);
// Verilog doesn't say that we must do short circuit
// evaluation of ternary expressions, but it doesn't disallow
// it. The disadvantage of doing this is that semantic errors
// in the unused clause will be missed, but people don't seem
// to mind, and do apreciate the optimization available here.
if (NetEConst*tmp = dynamic_cast<NetEConst*> (con)) {
verinum cval = tmp->value();
ivl_assert(*this, cval.len()==1);
// Condition is constant TRUE, so we only need the true claue.
if (cval.get(0) == verinum::V1) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: Short-circuit "
"elaborate TRUE clause of ternary."
<< endl;
ivl_assert(*this, use_wid > 0);
NetExpr*tru = elab_and_eval(des, scope, tru_, use_wid);
return pad_to_width(tru, use_wid);
}
// Condition is constant FALSE, so we only need the
// false clause.
if (cval.get(0) == verinum::V0) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: Short-circuit "
"elaborate FALSE clause of ternary."
<< endl;
ivl_assert(*this, use_wid > 0);
NetExpr*fal = elab_and_eval(des, scope, fal_, use_wid);
return pad_to_width(fal, use_wid);
}
// X and Z conditions need to blend both results, so we
// can't short-circuit.
}
NetExpr*tru = elab_and_eval(des, scope, tru_, use_wid);
if (tru == 0) {
delete con;
return 0;
}
NetExpr*fal = elab_and_eval(des, scope, fal_, use_wid);
if (fal == 0) {
delete con;
delete tru;
return 0;
}
if (! NetETernary::test_operand_compat(tru->expr_type(), fal->expr_type())) {
cerr << get_fileline() << ": error: Data types "
<< tru->expr_type() << " and "
<< fal->expr_type() << " of ternary"
<< " do not match." << endl;
des->errors += 1;
return 0;
}
suppress_binary_operand_sign_if_needed_(tru, fal);
/* Whatever the width we choose for the ternary operator, we
need to make sure the operands match. */
tru = pad_to_width(tru, use_wid);
fal = pad_to_width(fal, use_wid);
NetETernary*res = new NetETernary(con, tru, fal);
res->set_line(*this);
return res;
}
unsigned PEUnary::test_width(Design*des, NetScope*scope,
unsigned min, unsigned lval,
ivl_variable_type_t&expr_type__,
bool&unsized_flag)
{
switch (op_) {
case '!':
case '&': // Reduction AND
case '|': // Reduction OR
case '^': // Reduction XOR
case 'A': // Reduction NAND (~&)
case 'N': // Reduction NOR (~|)
case 'X': // Reduction NXOR (~^)
{
ivl_variable_type_t sub_type = IVL_VT_NO_TYPE;
bool flag = false;
expr_->test_width(des, scope, 0, 0, sub_type, flag);
expr_type_ = sub_type;
ivl_assert(*expr_, expr_type_ != IVL_VT_NO_TYPE);
}
expr_width_ = 1;
expr_type__ = expr_type_;
return expr_width_;
}
unsigned test_wid = expr_->test_width(des, scope, min, lval, expr_type__, unsized_flag);
switch (op_) {
// For these operators, the act of padding to the
// minimum width can have an important impact on the
// calculation. So don't let the tested width be less
// then the tested width.
case '-':
case '+':
case '~':
if (test_wid < min)
test_wid = min;
break;
}
expr_type_ = expr_type__;
expr_width_ = test_wid;
return test_wid;
}
NetExpr* PEUnary::elaborate_expr(Design*des, NetScope*scope,
int expr_wid, bool) const
{
/* Reduction operators and ! always have a self determined width. */
switch (op_) {
case '!':
case '&': // Reduction AND
case '|': // Reduction OR
case '^': // Reduction XOR
case 'A': // Reduction NAND (~&)
case 'N': // Reduction NOR (~|)
case 'X': // Reduction NXOR (~^)
expr_wid = -1;
default:
break;
}
NetExpr*ip = expr_->elaborate_expr(des, scope, expr_wid, false);
if (ip == 0) return 0;
NetExpr*tmp;
switch (op_) {
default:
tmp = new NetEUnary(op_, ip);
tmp->set_line(*this);
break;
case '-':
if (NetEConst*ipc = dynamic_cast<NetEConst*>(ip)) {
verinum val = ipc->value();
if (expr_wid > 0)
val = pad_to_width(val, expr_wid);
/* When taking the - of a number, extend it one
bit to accommodate a possible sign bit.
NOTE: This may not be correct! The test_width
is supposed to detect the special case that we
want to do lossless self-determined
expressions, and the function that calls
elaborate_expr should account for that in the
expr_wid argument. */
unsigned use_len = val.len();
if (expr_wid < 0)
use_len += 1;
/* Calculate unary minus as 0-val */
verinum zero (verinum::V0, use_len, val.has_len());
zero.has_sign(val.has_sign());
verinum nval = zero - val;
if (val.has_len())
nval = verinum(nval, val.len());
nval.has_sign(val.has_sign());
tmp = new NetEConst(nval);
tmp->set_line(*this);
delete ip;
} else if (NetECReal*ipr = dynamic_cast<NetECReal*>(ip)) {
/* When taking the - of a real, fold this into the
constant value. */
verireal val = - ipr->value();
tmp = new NetECReal(val);
tmp->set_line( *ip );
delete ip;
} else {
if (expr_wid > 0)
ip = pad_to_width(ip, expr_wid);
tmp = new NetEUnary(op_, ip);
tmp->set_line(*this);
}
break;
case '+':
tmp = ip;
break;
case '!': // Logical NOT
/* If the operand to unary ! is a constant, then I can
evaluate this expression here and return a logical
constant in its place. */
if (NetEConst*ipc = dynamic_cast<NetEConst*>(ip)) {
verinum val = ipc->value();
unsigned v1 = 0;
unsigned vx = 0;
for (unsigned idx = 0 ; idx < val.len() ; idx += 1)
switch (val[idx]) {
case verinum::V0:
break;
case verinum::V1:
v1 += 1;
break;
default:
vx += 1;
break;
}
verinum::V res;
if (v1 > 0)
res = verinum::V0;
else if (vx > 0)
res = verinum::Vx;
else
res = verinum::V1;
verinum vres (res, 1, true);
tmp = new NetEConst(vres);
tmp->set_line(*this);
delete ip;
} else {
tmp = new NetEUReduce(op_, ip);
tmp->set_line(*this);
}
break;
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;
case '~':
tmp = elaborate_expr_bits_(ip, expr_wid);
break;
}
return tmp;
}
NetExpr* PEUnary::elaborate_expr_bits_(NetExpr*operand, int expr_wid) const
{
// Handle the special case that the operand is a
// constant. Simply calculate the constant results of the
// expression and return that.
if (NetEConst*ctmp = dynamic_cast<NetEConst*> (operand)) {
verinum value = ctmp->value();
if (expr_wid > (int)value.len())
value = pad_to_width(value, expr_wid);
// The only operand that I know can get here is the
// unary not (~).
ivl_assert(*this, op_ == '~');
value = v_not(value);
ctmp = new NetEConst(value);
ctmp->set_line(*this);
delete operand;
return ctmp;
}
if (expr_wid > (int)operand->expr_width())
operand = pad_to_width(operand, expr_wid);
NetEUBits*tmp = new NetEUBits(op_, operand);
tmp->set_line(*this);
return tmp;
}
NetNet* Design::find_discipline_reference(ivl_discipline_t dis, NetScope*scope)
{
NetNet*gnd = discipline_references_[dis->name()];
if (gnd) return gnd;
string name = string(dis->name()) + "$gnd";
gnd = new NetNet(scope, lex_strings.make(name), NetNet::WIRE, 1);
gnd->set_discipline(dis);
gnd->data_type(IVL_VT_REAL);
discipline_references_[dis->name()] = gnd;
if (debug_elaborate)
cerr << gnd->get_fileline() << ": debug: "
<< "Create an implicit reference terminal"
<< " for discipline=" << dis->name()
<< " in scope=" << scope_path(scope) << endl;
return gnd;
}
Reference in New Issue View Git Blame Copy Permalink