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Fix some constant bit/part select bugs and add warnings. 

This patch fixes a few bugs in constant bit/part selects and
adds optional warnings for out of bound or undefined selects.
This commit is contained in:
Cary R 2010-01-09 19:57:01 -08:00 committed by Stephen Williams
parent d0b1936fb5
commit 5a0363ebd3
2 changed files with 185 additions and 60 deletions
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5
PExpr.h
View File

@ -1,7 +1,7 @@
#ifndef __PExpr_H
#define __PExpr_H
/*
* Copyright (c) 1998-2009 Stephen Williams <steve@icarus.com>
* Copyright (c) 1998-2010 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
@ -307,7 +307,8 @@ class PEIdent : public PExpr {
NetExpr* calculate_up_do_base_(Design*, NetScope*) const;
bool calculate_param_range_(Design*, NetScope*,
const NetExpr*msb_ex, long&msb,
const NetExpr*lsb_ex, long&lsb) const;
const NetExpr*lsb_ex, long&lsb,
long length) const;
bool calculate_up_do_width_(Design*, NetScope*, unsigned long&wid) const;

240
elab_expr.cc
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 1999-2009 Stephen Williams (steve@icarus.com)
* Copyright (c) 1999-2010 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
@ -1869,15 +1869,14 @@ NetExpr* PEIdent::calculate_up_do_base_(Design*des, NetScope*scope) const
bool PEIdent::calculate_param_range_(Design*des, NetScope*scope,
const NetExpr*par_msb, long&par_msv,
const NetExpr*par_lsb, long&par_lsv) const
const NetExpr*par_lsb, long&par_lsv,
long length) 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.
// just return range values of [length-1:0].
ivl_assert(*this, par_lsb == 0);
par_msv = 0;
par_msv = length-1;
par_lsv = 0;
return true;
}
@ -2211,13 +2210,13 @@ static verinum param_part_select_bits(const verinum&par_val, long wid,
for (long idx = 0 ; idx < wid ; idx += 1) {
long off = idx + lsv;
if (off < 0)
result.set(idx, verinum::Vx);
continue;
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);
continue;
else // Unsized parameters are "infinite" width.
result.set(idx, sign_bit(par_val));
}
@ -2242,18 +2241,28 @@ NetExpr* PEIdent::elaborate_expr_param_part_(Design*des, NetScope*scope,
if (!flag)
return 0;
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
long par_msv, par_lsv;
flag = calculate_param_range_(des, scope, par_msb, par_msv, par_lsb, par_lsv);
if (!flag)
return 0;
if (! calculate_param_range_(des, scope, par_msb, par_msv,
par_lsb, par_lsv,
par_ex->value().len())) return 0;
if (! parts_defined_flag) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: Part select of parameter "
<< "has x/z bits, so resorting to 'bx result." << endl;
if (warn_ob_select) {
const index_component_t&psel = path_.back().index.back();
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": warning: "
"Undefined part select [" << *(psel.msb) << ":"
<< *(psel.lsb) << "] for parameter '" << name
<< "'." << endl;
cerr << get_fileline() << ": : "
"Replacing select with a constant 'bx." << endl;
}
long wid = 1 + labs(par_msv-par_lsv);
NetEConst*tmp = make_const_x(wid);
NetEConst*tmp = new NetEConst(verinum(verinum::Vx, 1, false));
tmp->set_line(*this);
return tmp;
}
@ -2264,7 +2273,8 @@ NetExpr* PEIdent::elaborate_expr_param_part_(Design*des, NetScope*scope,
// 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 "
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": error: Part select " << name
<< "[" << msv << ":" << lsv << "] is out of order." << endl;
des->errors += 1;
return 0;
@ -2272,15 +2282,40 @@ NetExpr* PEIdent::elaborate_expr_param_part_(Design*des, NetScope*scope,
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;
// Watch out for reversed bit numbering. We're making
// the part select from LSB to MSB.
long base;
if (par_msv < par_lsv) {
base = par_lsv - lsv;
} else {
base = lsv - par_lsv;
}
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
if (warn_ob_select) {
if (base < 0) {
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": warning: Part select "
<< "[" << msv << ":" << lsv << "] is selecting "
"before the parameter " << name << "[";
if (par_ex->value().has_len()) cerr << par_msv;
else cerr << "<inf>";
cerr << ":" << par_lsv << "]." << endl;
cerr << get_fileline() << ": : Replacing "
"the out of bound bits with 'bx." << endl;
}
if (par_ex->value().has_len() &&
(base+wid > (long)par->expr_width())) {
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": warning: Part select "
<< name << "[" << msv << ":" << lsv << "] is selecting "
"after the parameter " << name << "[" << par_msv
<< ":" << par_lsv << "]." << endl;
cerr << get_fileline() << ": : Replacing "
"the out of bound bits with 'bx." << endl;
}
}
verinum result = param_part_select_bits(par_ex->value(), wid, lsv-par_lsv);
verinum result = param_part_select_bits(par_ex->value(), wid, base);
NetEConst*result_ex = new NetEConst(result);
result_ex->set_line(*this);
@ -2324,9 +2359,13 @@ NetExpr* PEIdent::elaborate_expr_param_idx_up_(Design*des, NetScope*scope,
const NetExpr*par_msb,
const NetExpr*par_lsb) const
{
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
long par_msv, par_lsv;
if(! calculate_param_range_(des, scope, par_msb, par_msv,
par_lsb, par_lsv)) return 0;
par_lsb, par_lsv,
par_ex->value().len())) return 0;
NetExpr*base = calculate_up_do_base_(des, scope);
if (base == 0) return 0;
@ -2334,9 +2373,6 @@ NetExpr* PEIdent::elaborate_expr_param_idx_up_(Design*des, NetScope*scope,
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 "
@ -2406,9 +2442,13 @@ NetExpr* PEIdent::elaborate_expr_param_idx_do_(Design*des, NetScope*scope,
const NetExpr*par_msb,
const NetExpr*par_lsb) const
{
const NetEConst*par_ex = dynamic_cast<const NetEConst*> (par);
ivl_assert(*this, par_ex);
long par_msv, par_lsv;
if(! calculate_param_range_(des, scope, par_msb, par_msv,
par_lsb, par_lsv)) return 0;
par_lsb, par_lsv,
par_ex->value().len())) return 0;
NetExpr*base = calculate_up_do_base_(des, scope);
if (base == 0) return 0;
@ -2416,9 +2456,6 @@ NetExpr* PEIdent::elaborate_expr_param_idx_do_(Design*des, NetScope*scope,
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 "
@ -2565,11 +2602,16 @@ NetExpr* PEIdent::elaborate_expr_param_(Design*des,
// not fully defined, then we know that the result
// must be 1'bx.
if (! re->value().is_defined()) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: "
<< "Constant bit select of parameter is "
<< "not defined. Return constant X value."
<< endl;
if (warn_ob_select) {
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": warning: "
"Constant undefined bit select ["
<< re->value() << "] for parameter '"
<< name << "'." << endl;
cerr << get_fileline() << ": : "
"Replacing select with a constant "
"1'bx." << endl;
}
NetEConst*res = make_const_x(1);
res->set_line(*this);
return res;
@ -2592,7 +2634,7 @@ NetExpr* PEIdent::elaborate_expr_param_(Design*des,
if (par_mv >= par_lv) {
ridx -= par_lv;
} else {
ridx = par_mv - ridx + par_lv;
ridx = par_lv - ridx;
}
if ((ridx >= 0) && ((unsigned long) ridx < lv.len())) {
@ -2603,8 +2645,25 @@ NetExpr* PEIdent::elaborate_expr_param_(Design*des,
rb = lv[lv.len()-1];
else
rb = verinum::V0;
} else {
if (warn_ob_select) {
perm_string name = peek_tail_name(path_);
cerr << get_fileline() << ": warning: "
"Constant bit select [" << rv.as_long()
<< "] is ";
if (ridx < 0) cerr << "before ";
else cerr << "after ";
cerr << name << "[";
if (lv.has_len()) cerr << par_mv;
else cerr << "<inf>";
cerr << ":" << par_lv << "]." << endl;
cerr << get_fileline() << ": : "
"Replacing select with a constant "
"1'bx." << endl;
}
}
NetEConst*re2 = new NetEConst(verinum(rb, 1));
delete tmp;
delete mtmp;
@ -2803,27 +2862,67 @@ NetExpr* PEIdent::elaborate_expr_net_part_(Design*des, NetScope*scope,
/* But wait... if the part select expressions are not fully
defined, then fall back on the tested width. */
if (!parts_defined_flag) {
if (debug_elaborate)
cerr << get_fileline() << ": debug: Part select is not fully "
<< "defined. Falling back on width of " << expr_width_
<< " and generating constant 'bx vector." << endl;
NetEConst*tmp = make_const_x(expr_width_);
if (warn_ob_select) {
const index_component_t&psel = path_.back().index.back();
cerr << get_fileline() << ": warning: "
"Undefined part select [" << *(psel.msb) << ":"
<< *(psel.lsb) << "] for ";
if (net->word_index()) cerr << "array word";
else cerr << "vector";
cerr << " '" << net->name();
if (net->word_index()) cerr << "[]";
cerr << "'." << endl;
cerr << get_fileline() << ": : "
"Replacing select with a constant 'bx." << endl;
}
NetEConst*tmp = new NetEConst(verinum(verinum::Vx, 1, false));
tmp->set_line(*this);
return tmp;
}
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;
long sb_lsb = net->sig()->sb_to_idx(lsv);
long sb_msb = net->sig()->sb_to_idx(msv);
if (sb_msb < sb_lsb) {
cerr << get_fileline() << ": error: part select " << net->name();
if (net->word_index()) cerr << "[]";
cerr << "[" << msv << ":" << lsv << "] is 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 (warn_ob_select) {
if ((sb_lsb >= (signed) net->vector_width()) ||
(sb_msb >= (signed) net->vector_width())) {
cerr << get_fileline() << ": warning: "
"Part select " << "[" << msv << ":" << lsv
<< "] is selecting after the ";
if (net->word_index()) cerr << "array word ";
else cerr << "vector ";
cerr << net->name();
if (net->word_index()) cerr << "[]";
cerr << "[" << net->msi() << ":" << net->lsi() << "]."
<< endl;
cerr << get_fileline() << ": : "
<< "Replacing the out of bound bits with 'bx." << endl;
}
if ((sb_msb < 0) || (sb_lsb < 0)) {
cerr << get_fileline() << ": warning: "
"Part select " << "[" << msv << ":" << lsv
<< "] is selecting before the ";
if (net->word_index()) cerr << "array word ";
else cerr << "vector ";
cerr << net->name();
if (net->word_index()) cerr << "[]";
cerr << "[" << net->msi() << ":" << net->lsi() << "]."
<< endl;
cerr << get_fileline() << ": : "
"Replacing the out of bound bits with 'bx." << endl;
}
}
// If the part select covers exactly the entire
// vector, then do not bother with it. Return the
@ -3050,9 +3149,23 @@ NetExpr* PEIdent::elaborate_expr_net_bit_(Design*des, NetScope*scope,
// making a mux part in the netlist.
if (NetEConst*msc = dynamic_cast<NetEConst*> (ex)) {
// Special case: The bit select expresion is constant
// Special case: The bit select expression is constant
// x/z. The result of the expression is 1'bx.
if (! msc->value().is_defined()) {
if (warn_ob_select) {
cerr << get_fileline() << ": warning: "
"Constant bit select [" << msc->value()
<< "] is undefined for ";
if (net->word_index()) cerr << "array word";
else cerr << "vector";
cerr << " '" << net->name();
if (net->word_index()) cerr << "[]";
cerr << "'." << endl;
cerr << get_fileline() << ": : "
<< "Replacing select with a constant 1'bx."
<< endl;
}
NetEConst*tmp = make_const_x(1);
tmp->set_line(*this);
delete ex;
@ -3060,21 +3173,32 @@ NetExpr* PEIdent::elaborate_expr_net_bit_(Design*des, NetScope*scope,
}
long msv = msc->value().as_long();
unsigned idx = net->sig()->sb_to_idx(msv);
long idx = net->sig()->sb_to_idx(msv);
if (idx >= net->vector_width()) {
if (idx >= (long)net->vector_width() || idx < 0) {
/* The bit select is out of range of the
vector. This is legal, but returns a
constant 1'bx value. */
if (warn_ob_select) {
cerr << get_fileline() << ": warning: "
"Constant bit select [" << msv
<< "] is ";
if (idx < 0) cerr << "before ";
else cerr << "after ";
if (net->word_index()) cerr << "array word ";
else cerr << "vector ";
cerr << net->name();
if (net->word_index()) cerr << "[]";
cerr << "[" << net->sig()->msb() << ":"
<< net->sig()->lsb() << "]." << endl;
cerr << get_fileline() << ": : "
<< "Replacing select with a constant 1'bx."
<< endl;
}
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;
}