383 lines
10 KiB
C++
383 lines
10 KiB
C++
// OpenSTA, Static Timing Analyzer
|
|
// Copyright (c) 2018, Parallax Software, Inc.
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 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, see <https://www.gnu.org/licenses/>.
|
|
|
|
#include "Machine.hh"
|
|
#include "Fuzzy.hh"
|
|
#include "Liberty.hh"
|
|
#include "Network.hh"
|
|
#include "Sdc.hh"
|
|
#include "Graph.hh"
|
|
#include "StaState.hh"
|
|
#include "DcalcAnalysisPt.hh"
|
|
#include "Corner.hh"
|
|
#include "PathVertex.hh"
|
|
#include "Search.hh"
|
|
#include "CheckSlewLimits.hh"
|
|
|
|
namespace sta {
|
|
|
|
class PinSlewLimitSlackLess
|
|
{
|
|
public:
|
|
PinSlewLimitSlackLess(const Corner *corner,
|
|
const MinMax *min_max,
|
|
CheckSlewLimits *check_slew_limit,
|
|
const StaState *sta);
|
|
bool operator()(Pin *pin1,
|
|
Pin *pin2) const;
|
|
|
|
private:
|
|
const Corner *corner_;
|
|
const MinMax *min_max_;
|
|
CheckSlewLimits *check_slew_limit_;
|
|
const StaState *sta_;
|
|
|
|
};
|
|
|
|
PinSlewLimitSlackLess::PinSlewLimitSlackLess(const Corner *corner,
|
|
const MinMax *min_max,
|
|
CheckSlewLimits *check_slew_limit,
|
|
const StaState *sta) :
|
|
corner_(corner),
|
|
min_max_(min_max),
|
|
check_slew_limit_(check_slew_limit),
|
|
sta_(sta)
|
|
{
|
|
}
|
|
|
|
bool
|
|
PinSlewLimitSlackLess::operator()(Pin *pin1,
|
|
Pin *pin2) const
|
|
{
|
|
const Corner *corner1, *corner2;
|
|
const TransRiseFall *tr1, *tr2;
|
|
Slew slew1, slew2;
|
|
float limit1, limit2, slack1, slack2;
|
|
check_slew_limit_->checkSlews(pin1, corner_, min_max_,
|
|
corner1, tr1, slew1, limit1, slack1);
|
|
check_slew_limit_->checkSlews(pin2, corner_, min_max_,
|
|
corner2, tr2, slew2, limit2, slack2);
|
|
return slack1 < slack2
|
|
|| (fuzzyEqual(slack1, slack2)
|
|
// Break ties for the sake of regression stability.
|
|
&& sta_->network()->pinLess(pin1, pin2));
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////
|
|
|
|
CheckSlewLimits::CheckSlewLimits(const StaState *sta) :
|
|
sta_(sta)
|
|
{
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::init(const MinMax *min_max)
|
|
{
|
|
const Network *network = sta_->network();
|
|
Cell *top_cell = network->cell(network->topInstance());
|
|
float top_limit;
|
|
bool top_limit_exists;
|
|
sta_->sdc()->slewLimit(top_cell, min_max,
|
|
top_limit, top_limit_exists);
|
|
top_limit_= top_limit;
|
|
top_limit_exists_ = top_limit_exists;
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::checkSlews(const Pin *pin,
|
|
const Corner *corner,
|
|
const MinMax *min_max,
|
|
// Return values.
|
|
const Corner *&corner1,
|
|
const TransRiseFall *&tr,
|
|
Slew &slew,
|
|
float &limit,
|
|
float &slack) const
|
|
{
|
|
corner1 = NULL;
|
|
tr = NULL;
|
|
slack = MinMax::min()->initValue();
|
|
if (corner)
|
|
checkSlews1(pin, corner, min_max,
|
|
corner1, tr, slew, limit, slack);
|
|
else {
|
|
CornerIterator corner_iter(sta_);
|
|
while (corner_iter.hasNext()) {
|
|
const Corner *corner2 = corner_iter.next();
|
|
checkSlews1(pin, corner2, min_max,
|
|
corner1, tr, slew, limit, slack);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::checkSlews1(const Pin *pin,
|
|
const Corner *corner,
|
|
const MinMax *min_max,
|
|
// Return values.
|
|
const Corner *&corner1,
|
|
const TransRiseFall *&tr,
|
|
Slew &slew,
|
|
float &limit,
|
|
float &slack) const
|
|
{
|
|
Vertex *vertex, *bidirect_drvr_vertex;
|
|
sta_->graph()->pinVertices(pin, vertex, bidirect_drvr_vertex);
|
|
checkSlews1(vertex, corner, min_max,
|
|
corner1, tr, slew, limit, slack);
|
|
if (bidirect_drvr_vertex)
|
|
checkSlews1(bidirect_drvr_vertex, corner, min_max,
|
|
corner1, tr, slew, limit, slack);
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::checkSlews1(Vertex *vertex,
|
|
const Corner *corner1,
|
|
const MinMax *min_max,
|
|
// Return values.
|
|
const Corner *&corner,
|
|
const TransRiseFall *&tr,
|
|
Slew &slew,
|
|
float &limit,
|
|
float &slack) const
|
|
{
|
|
TransRiseFallIterator tr_iter;
|
|
while (tr_iter.hasNext()) {
|
|
TransRiseFall *tr1 = tr_iter.next();
|
|
float limit1;
|
|
bool limit1_exists;
|
|
findLimit(vertex->pin(), vertex, tr1, min_max, limit1, limit1_exists);
|
|
if (limit1_exists) {
|
|
checkSlew(vertex, corner1, min_max, tr1, limit1,
|
|
corner, tr, slew, slack, limit);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::findLimit(const Pin *pin,
|
|
const Vertex *vertex,
|
|
const TransRiseFall *tr,
|
|
const MinMax *min_max,
|
|
// Return values.
|
|
float &limit1,
|
|
bool &limit1_exists) const
|
|
|
|
{
|
|
limit1_exists = false;
|
|
const Network *network = sta_->network();
|
|
Sdc *sdc = sta_->sdc();
|
|
bool is_clk = sta_->search()->isClock(vertex);
|
|
// Look for clock slew limits.
|
|
ClockSet clks;
|
|
clockDomains(vertex, clks);
|
|
ClockSet::Iterator clk_iter(clks);
|
|
while (clk_iter.hasNext()) {
|
|
Clock *clk = clk_iter.next();
|
|
PathClkOrData clk_data = is_clk ? path_clk : path_data;
|
|
float clk_limit;
|
|
bool clk_limit_exists;
|
|
sdc->slewLimit(clk, tr, clk_data, min_max,
|
|
clk_limit, clk_limit_exists);
|
|
if (clk_limit_exists
|
|
&& (!limit1_exists
|
|
|| min_max->compare(limit1, clk_limit))) {
|
|
// Use the tightest clock limit.
|
|
limit1 = clk_limit;
|
|
limit1_exists = true;
|
|
}
|
|
}
|
|
if (!limit1_exists) {
|
|
// Default to top ("design") limit.
|
|
limit1_exists = top_limit_exists_;
|
|
limit1 = top_limit_;
|
|
if (network->isTopLevelPort(pin)) {
|
|
Port *port = network->port(pin);
|
|
float port_limit;
|
|
bool port_limit_exists;
|
|
sdc->slewLimit(port, min_max, port_limit, port_limit_exists);
|
|
// Use the tightest limit.
|
|
if (port_limit_exists
|
|
&& (!limit1_exists
|
|
|| min_max->compare(limit1, port_limit))) {
|
|
limit1 = port_limit;
|
|
limit1_exists = true;
|
|
}
|
|
}
|
|
else {
|
|
float pin_limit;
|
|
bool pin_limit_exists;
|
|
sdc->slewLimit(pin, min_max,
|
|
pin_limit, pin_limit_exists);
|
|
// Use the tightest limit.
|
|
if (pin_limit_exists
|
|
&& (!limit1_exists
|
|
|| min_max->compare(limit1, pin_limit))) {
|
|
limit1 = pin_limit;
|
|
limit1_exists = true;
|
|
}
|
|
|
|
float port_limit;
|
|
bool port_limit_exists;
|
|
LibertyPort *port = network->libertyPort(pin);
|
|
if (port) {
|
|
port->slewLimit(min_max, port_limit, port_limit_exists);
|
|
// Use the tightest limit.
|
|
if (port_limit_exists
|
|
&& (!limit1_exists
|
|
|| min_max->compare(limit1, port_limit))) {
|
|
limit1 = port_limit;
|
|
limit1_exists = true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::clockDomains(const Vertex *vertex,
|
|
// Return value.
|
|
ClockSet &clks) const
|
|
{
|
|
VertexPathIterator path_iter(const_cast<Vertex*>(vertex), sta_);
|
|
while (path_iter.hasNext()) {
|
|
Path *path = path_iter.next();
|
|
Clock *clk = path->clock(sta_);
|
|
if (clk)
|
|
clks.insert(clk);
|
|
}
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::checkSlew(Vertex *vertex,
|
|
const Corner *corner1,
|
|
const MinMax *min_max,
|
|
const TransRiseFall *tr1,
|
|
float limit1,
|
|
// Return values.
|
|
const Corner *&corner,
|
|
const TransRiseFall *&tr,
|
|
Slew &slew,
|
|
float &slack,
|
|
float &limit) const
|
|
{
|
|
const DcalcAnalysisPt *dcalc_ap = corner1->findDcalcAnalysisPt(min_max);
|
|
Slew slew1 = sta_->graph()->slew(vertex, tr1, dcalc_ap->index());
|
|
float slew2 = delayAsFloat(slew1);
|
|
float slack1 = (min_max == MinMax::max())
|
|
? limit1 - slew2 : slew2 - limit1;
|
|
if (corner == NULL
|
|
|| (slack1 < slack
|
|
// Break ties for the sake of regression stability.
|
|
|| (fuzzyEqual(slack1, slack)
|
|
&& tr1->index() < tr->index()))) {
|
|
corner = corner1;
|
|
tr = tr1;
|
|
slew = slew1;
|
|
slack = slack1;
|
|
limit = limit1;
|
|
}
|
|
}
|
|
|
|
PinSeq *
|
|
CheckSlewLimits::pinSlewLimitViolations(const Corner *corner,
|
|
const MinMax *min_max)
|
|
{
|
|
init(min_max);
|
|
const Network *network = sta_->network();
|
|
PinSeq *violators = new PinSeq;
|
|
LeafInstanceIterator *inst_iter = network->leafInstanceIterator();
|
|
while (inst_iter->hasNext()) {
|
|
Instance *inst = inst_iter->next();
|
|
pinSlewLimitViolations(inst, corner, min_max, violators);
|
|
}
|
|
delete inst_iter;
|
|
// Check top level ports.
|
|
pinSlewLimitViolations(network->topInstance(), corner, min_max, violators);
|
|
sort(violators, PinSlewLimitSlackLess(corner, min_max, this, sta_));
|
|
return violators;
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::pinSlewLimitViolations(Instance *inst,
|
|
const Corner *corner,
|
|
const MinMax *min_max,
|
|
PinSeq *violators)
|
|
{
|
|
const Network *network = sta_->network();
|
|
InstancePinIterator *pin_iter = network->pinIterator(inst);
|
|
while (pin_iter->hasNext()) {
|
|
Pin *pin = pin_iter->next();
|
|
const Corner *corner1;
|
|
const TransRiseFall *tr;
|
|
Slew slew;
|
|
float limit, slack;
|
|
checkSlews(pin, corner, min_max, corner1, tr, slew, limit, slack );
|
|
if (tr && slack < 0.0)
|
|
violators->push_back(pin);
|
|
}
|
|
delete pin_iter;
|
|
}
|
|
|
|
Pin *
|
|
CheckSlewLimits::pinMinSlewLimitSlack(const Corner *corner,
|
|
const MinMax *min_max)
|
|
{
|
|
init(min_max);
|
|
const Network *network = sta_->network();
|
|
Pin *min_slack_pin = 0;
|
|
float min_slack = MinMax::min()->initValue();
|
|
LeafInstanceIterator *inst_iter = network->leafInstanceIterator();
|
|
while (inst_iter->hasNext()) {
|
|
Instance *inst = inst_iter->next();
|
|
pinMinSlewLimitSlack(inst, corner, min_max, min_slack_pin, min_slack);
|
|
}
|
|
delete inst_iter;
|
|
// Check top level ports.
|
|
pinMinSlewLimitSlack(network->topInstance(), corner, min_max,
|
|
min_slack_pin, min_slack);
|
|
return min_slack_pin;
|
|
}
|
|
|
|
void
|
|
CheckSlewLimits::pinMinSlewLimitSlack(Instance *inst,
|
|
const Corner *corner,
|
|
const MinMax *min_max,
|
|
// Return values.
|
|
Pin *&min_slack_pin,
|
|
float &min_slack)
|
|
{
|
|
const Network *network = sta_->network();
|
|
InstancePinIterator *pin_iter = network->pinIterator(inst);
|
|
while (pin_iter->hasNext()) {
|
|
Pin *pin = pin_iter->next();
|
|
const Corner *corner1;
|
|
const TransRiseFall *tr;
|
|
Slew slew;
|
|
float limit, slack;
|
|
checkSlews(pin, corner, min_max, corner1, tr, slew, limit, slack);
|
|
if (tr
|
|
&& (min_slack_pin == 0
|
|
|| slack < min_slack)) {
|
|
min_slack_pin = pin;
|
|
min_slack = slack;
|
|
}
|
|
}
|
|
delete pin_iter;
|
|
}
|
|
|
|
} // namespace
|