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Combine constants into a bit table.

This commit is contained in:
steve 2000-05-20 02:26:23 +00:00
parent 28df01b880
commit b93415e8f1
1 changed files with 151 additions and 8 deletions
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159
t-vvm.cc
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT) && !defined(macintosh)
#ident "$Id: t-vvm.cc,v 1.149 2000/05/11 23:37:27 steve Exp $"
#ident "$Id: t-vvm.cc,v 1.150 2000/05/20 02:26:23 steve Exp $"
#endif
# include <iostream>
@ -38,6 +38,97 @@ struct less_verinum {
{ return left.is_before(right); }
};
/*
* The generated code puts constants in behavioral expressions into a
* bit number table. Every place in the code where a vvm_bits_t is
* created, it references an offset and size into this table. the
* table is collected as numbers are encountered, overlapping values
* as much as possible so that the number of output bits is reduced.
*/
class NumberTable {
public:
NumberTable();
~NumberTable();
unsigned position(const verinum&val);
unsigned count() const { return nbits_; }
verinum::V bit(unsigned idx) const { return bits_[idx]; }
private:
verinum::V*bits_;
unsigned nbits_;
};
NumberTable::NumberTable()
{
bits_ = 0;
nbits_ = 0;
}
NumberTable::~NumberTable()
{
if (bits_) delete[]bits_;
}
unsigned NumberTable::position(const verinum&val)
{
if (bits_ == 0) {
nbits_ = val.len();
bits_ = new verinum::V[val.len()];
for (unsigned idx = 0 ; idx < nbits_ ; idx += 1)
bits_[idx] = val.get(idx);
return 0;
}
/* Look for a complete match. If I find one, then return the
index of the start and all done. */
for (unsigned idx = 0 ; (idx+val.len()) < nbits_ ; idx += 1) {
bool match_flag = true;
for (unsigned bit = 0 ; bit < val.len() ; bit += 1)
if (bits_[idx+bit] != val.get(bit)) {
match_flag = false;
break;
}
if (match_flag)
return idx;
}
unsigned tail_match = 0;
for (unsigned idx = 1; (idx < val.len()) && (idx < nbits_) ; idx += 1) {
bool match_flag = true;
for (unsigned bit = 0 ; bit < idx ; bit += 1)
if (bits_[nbits_-idx+bit] != val.get(bit)) {
match_flag = false;
break;
}
if (match_flag)
tail_match = idx;
}
unsigned ntmp = nbits_+val.len()-tail_match;
verinum::V*tmp = new verinum::V[ntmp];
for (unsigned idx = 0 ; idx < nbits_ ; idx += 1)
tmp[idx] = bits_[idx];
for (unsigned idx = nbits_ ; idx < ntmp ; idx += 1)
tmp[idx] = val.get(idx-nbits_+tail_match);
unsigned rc = nbits_ - tail_match;
delete[]bits_;
bits_ = tmp;
nbits_ = ntmp;
return rc;
}
static string make_temp()
{
static unsigned counter = 0;
@ -110,6 +201,9 @@ class target_vvm : public target_t {
void start_process(ostream&os, const NetProcTop*);
void end_process(ostream&os, const NetProcTop*);
NumberTable bits_table;
private:
void emit_init_value_(const Link&lnk, verinum::V val);
void emit_gate_outputfun_(const NetNode*, unsigned);
@ -323,6 +417,11 @@ void vvm_proc_rval::expr_const(const NetEConst*expr)
{
string tname = make_temp();
unsigned number_off = tgt_->bits_table.position(expr->value());
os_ << " vvm_bitset_t " << tname << "(bits_table+"
<< number_off << ", " << expr->expr_width() << ");" << endl;
#if 0
os_ << " vpip_bit_t " << tname<<"_bits["
<< expr->expr_width() << "];" << endl;
for (unsigned idx = 0 ; idx < expr->expr_width() ; idx += 1) {
@ -346,7 +445,7 @@ void vvm_proc_rval::expr_const(const NetEConst*expr)
os_ << " vvm_bitset_t " << tname << "(" << tname
<< "_bits, " << expr->expr_width() << ");" << endl;
#endif
result = tname;
}
@ -912,6 +1011,34 @@ void target_vvm::end_design(ostream&os, const Design*mod)
os << "static vpip_bit_t signal_bit_table[" <<
signal_bit_counter << "];" << endl;
if (bits_table.count() > 0) {
os << "static vpip_bit_t bits_table[" << bits_table.count()
<< "] = {";
for (unsigned idx = 0 ; idx < bits_table.count() ; idx += 1) {
if (idx%16 == 0) os << endl;
switch (bits_table.bit(idx)) {
case verinum::V0:
os << " St0,";
break;
case verinum::V1:
os << " St1,";
break;
case verinum::Vx:
os << " StX,";
break;
case verinum::Vz:
os << " HiZ,";
break;
default:
os << " ,";
break;
}
}
os << endl << "};" << endl;
}
defn.close();
os << "// **** Definition code" << endl;
@ -2648,10 +2775,23 @@ bool target_vvm::proc_release(ostream&os, const NetRelease*dev)
void target_vvm::proc_repeat(ostream&os, const NetRepeat*net)
{
string expr = emit_proc_rval(defn, this, net->expr());
unsigned top_step = ++thread_step_;
unsigned out_step = ++thread_step_;
/* Emit the index expression value and convert it into a
native number. If the expression is a constant, then do it
directly. Otherwise, generate the code to do it. */
string expr;
if (const NetEConst*val = dynamic_cast<const NetEConst*>(net->expr())) {
char tmp[64];
sprintf(tmp, "%lu", val->value().as_ulong());
expr = tmp;
} else {
expr = emit_proc_rval(defn, this, net->expr());
expr = expr + ".as_unsigned()";
}
/* Declare a variable to use as a loop index. */
os << "static unsigned " << thread_class_ << "_step_"
<< top_step << "_idx_;" << endl;
@ -2666,7 +2806,7 @@ void target_vvm::proc_repeat(ostream&os, const NetRepeat*net)
defn << " " << thread_class_ << "_step_"
<< top_step << "_idx_ = " << expr << ".as_unsigned();" << endl;
<< top_step << "_idx_ = " << expr << ";" << endl;
defn << " thr->step_ = &" << thread_class_ << "_step_"
<< top_step << "_;" << endl;
defn << " return true;" << endl;
@ -2885,8 +3025,8 @@ void target_vvm::proc_while(ostream&os, const NetWhile*net)
void target_vvm::proc_delay(ostream&os, const NetPDelay*proc)
{
thread_step_ += 1;
defn << " thr->step_ = &" << thread_class_ << "_step_" <<
thread_step_ << "_;" << endl;
defn << " thr->step_ = &" << thread_class_ << "_step_"
<< thread_step_ << "_;" << endl;
defn << " thr->thread_yield(" << proc->delay() << ");" << endl;
defn << " return false;" << endl;
defn << "}" << endl;
@ -2894,8 +3034,8 @@ void target_vvm::proc_delay(ostream&os, const NetPDelay*proc)
os << "static bool " << thread_class_ << "_step_"
<< thread_step_ << "_(vvm_thread*thr);" << endl;
defn << "bool " << thread_class_ << "_step_" << thread_step_ <<
"_(vvm_thread*thr) {" << endl;
defn << "static bool " << thread_class_ << "_step_" << thread_step_
<< "_(vvm_thread*thr) {" << endl;
proc->emit_proc_recurse(os, this);
}
@ -2923,6 +3063,9 @@ extern const struct target tgt_vvm = {
};
/*
* $Log: t-vvm.cc,v $
* Revision 1.150 2000/05/20 02:26:23 steve
* Combine constants into a bit table.
*
* Revision 1.149 2000/05/11 23:37:27 steve
* Add support for procedural continuous assignment.
*