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Merge remote-tracking branch 'origin/master' into xc7mux

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This commit is contained in:
Eddie Hung 2019-05-28 09:30:53 -07:00
commit ba9513b325
17 changed files with 428 additions and 110 deletions
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5
passes/opt/opt_clean.cc
View file

@ -319,8 +319,9 @@ bool rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
wire->attributes.erase("\\init");
if (GetSize(wire) == 0) {
// delete zero-width wires
goto delete_this_wire;
// delete zero-width wires, unless they are module ports
if (wire->port_id == 0)
goto delete_this_wire;
} else
if (wire->port_id != 0 || wire->get_bool_attribute("\\keep") || !initval.is_fully_undef()) {
// do not delete anything with "keep" or module ports or initialized wires

57
passes/opt/opt_rmdff.cc
View file

@ -338,16 +338,6 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
val_init.bits.push_back(bit.wire == NULL ? bit.data : RTLIL::State::Sx);
}
if (sig_e.size()) {
if (!sig_e.is_fully_const())
return false;
if (sig_e != val_ep) {
if (has_init)
mod->connect(sig_q, val_init);
goto delete_dff;
}
}
if (dff->type.in("$ff", "$dff") && mux_drivers.has(sig_d)) {
std::set<RTLIL::Cell*> muxes;
mux_drivers.find(sig_d, muxes);
@ -365,39 +355,60 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
}
}
// If clock is driven by a constant and (i) no reset signal
// (ii) Q has no initial value
// (iii) initial value is same as reset value
if (!sig_c.empty() && sig_c.is_fully_const() && (!sig_r.size() || !has_init || val_init == val_rv)) {
if (val_rv.bits.size() == 0)
val_rv = val_init;
// Q is permanently reset value or initial value
mod->connect(sig_q, val_rv);
goto delete_dff;
}
// If D is fully undefined and reset signal present and (i) Q has no initial value
// (ii) initial value is same as reset value
if (sig_d.is_fully_undef() && sig_r.size() && (!has_init || val_init == val_rv)) {
// Q is permanently reset value
mod->connect(sig_q, val_rv);
goto delete_dff;
}
// If D is fully undefined and no reset signal and Q has an initial value
if (sig_d.is_fully_undef() && !sig_r.size() && has_init) {
// Q is permanently initial value
mod->connect(sig_q, val_init);
goto delete_dff;
}
// If D is fully constant and (i) no reset signal
// (ii) reset value is same as constant D
// and (a) has no initial value
// (b) initial value same as constant D
if (sig_d.is_fully_const() && (!sig_r.size() || val_rv == sig_d.as_const()) && (!has_init || val_init == sig_d.as_const())) {
// Q is permanently D
mod->connect(sig_q, sig_d);
goto delete_dff;
}
// If D input is same as Q output and (i) no reset signal
// (ii) no initial signal
// (iii) initial value is same as reset value
if (sig_d == sig_q && (sig_r.empty() || !has_init || val_init == val_rv)) {
// Q is permanently reset value or initial value
if (sig_r.size())
mod->connect(sig_q, val_rv);
if (has_init)
else if (has_init)
mod->connect(sig_q, val_init);
goto delete_dff;
}
// If reset signal is present, and is fully constant
if (!sig_r.empty() && sig_r.is_fully_const())
{
// If reset value is permanently active or if reset is undefined
if (sig_r == val_rp || sig_r.is_fully_undef()) {
// Q is permanently reset value
mod->connect(sig_q, val_rv);
goto delete_dff;
}
@ -417,6 +428,30 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
dff->unsetPort("\\R");
}
// If enable signal is present, and is fully constant
if (!sig_e.empty() && sig_e.is_fully_const())
{
// If enable value is permanently inactive
if (sig_e != val_ep) {
// Q is permanently initial value
mod->connect(sig_q, val_init);
goto delete_dff;
}
log("Removing unused enable from %s (%s) from module %s.\n", log_id(dff), log_id(dff->type), log_id(mod));
if (dff->type == "$dffe") {
dff->type = "$dff";
dff->unsetPort("\\EN");
dff->unsetParam("\\EN_POLARITY");
return true;
}
log_assert(dff->type.substr(0,7) == "$_DFFE_");
dff->type = stringf("$_DFF_%c_", + dff->type[7]);
dff->unsetPort("\\E");
}
return false;
delete_dff: