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Rework parameter indexed part select up. 

Indexed part select reworked to be more compact and more like the
part select.
This commit is contained in:
Stephen Williams 2008-06-08 19:29:00 -07:00
parent 7aebff2a86
commit 6a1235ac28
2 changed files with 111 additions and 30 deletions
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7
PExpr.h
View File

@ -306,6 +306,7 @@ class PEIdent : public PExpr {
private:
// Common functions to calculate parts of part/bit selects.
bool calculate_parts_(Design*, NetScope*, long&msb, long&lsb) const;
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;
@ -331,6 +332,12 @@ class PEIdent : public PExpr {
NetScope*found,
const NetExpr*par_msb,
const NetExpr*par_lsb) const;
NetExpr*elaborate_expr_param_idx_up_(Design*des,
NetScope*scope,
const NetExpr*par,
NetScope*found,
const NetExpr*par_msb,
const NetExpr*par_lsb) const;
NetExpr*elaborate_expr_net(Design*des,
NetScope*scope,
NetNet*net,

134
elab_expr.cc
View File

@ -882,6 +882,23 @@ bool PEIdent::calculate_up_do_width_(Design*des, NetScope*scope,
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
@ -1122,6 +1139,33 @@ NetExpr* PEIdent::elaborate_expr(Design*des, NetScope*scope,
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,
@ -1157,34 +1201,67 @@ NetExpr* PEIdent::elaborate_expr_param_part_(Design*des, NetScope*scope,
<< "[" << msv << ":" << lsv << "] from range "
<< "[" << par_msv << ":" << par_lsv << "]." << endl;
verinum result (verinum::Vx, wid, true);
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);
verinum par_val = par_ex->value();
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 (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 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))
result = verinum(result.as_string());
if ((par_msb < par_lsb) && (wid>1))
base = make_add_expr(base, 1-(long)wid);
NetEConst*result_ex = new NetEConst(result);
result_ex->set_line(*this);
return result_ex;
NetExpr*tmp = par->dup_expr();
tmp = new NetESelect(tmp, base, wid);
tmp->set_line(*this);
return tmp;
}
/*
@ -1212,12 +1289,16 @@ NetExpr* PEIdent::elaborate_expr_param(Design*des,
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_UP || use_sel == index_component_t::SEL_IDX_DO) {
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();
@ -1562,14 +1643,7 @@ NetExpr* PEIdent::elaborate_expr_net_part_(Design*des, NetScope*scope,
NetExpr* PEIdent::elaborate_expr_net_idx_up_(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);
NetExpr*base = calculate_up_do_base_(des, scope);
unsigned long wid = 0;
calculate_up_do_width_(des, scope, wid);