Undo #895 by instead setting an attribute

This commit is contained in:
Eddie Hung 2019-04-08 16:05:24 -07:00
parent dfb242c905
commit 13fc70d7a4
1 changed files with 3 additions and 17 deletions

View File

@ -360,23 +360,9 @@ RTLIL::SigSpec signal_to_mux_tree(RTLIL::Module *mod, SnippetSwCache &swcache, d
}
}
// Transform into a $shiftx where possible
if (shiftx && last_mux_cell && last_mux_cell->type == "$pmux") {
// Create bit-blasted $shiftx-es that shifts by the address line used in the case statement
auto pmux_b_port = last_mux_cell->getPort("\\B");
auto pmux_y_port = last_mux_cell->getPort("\\Y");
int width = last_mux_cell->getParam("\\WIDTH").as_int();
for (int i = 0; i < width; ++i) {
RTLIL::SigSpec a_port;
// Because we went in reverse order above, un-reverse $pmux's B port here
for (int j = pmux_b_port.size()/width-1; j >= 0; --j)
a_port.append(pmux_b_port.extract(j*width+i, 1));
// Create a $shiftx that shifts by the address line used in the case statement
mod->addShiftx(NEW_ID, a_port, sw->signal, pmux_y_port.extract(i, 1));
}
// Disconnect $pmux by replacing its output port with a floating wire
last_mux_cell->setPort("\\Y", mod->addWire(NEW_ID, width));
}
// Mark this pmux as being $shiftx compatible
if (shiftx && last_mux_cell && last_mux_cell->type == "$pmux")
last_mux_cell->set_bool_attribute("\\shiftx_compatible");
}
return result;