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Added opt_const -mux_bool

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This commit is contained in:
Clifford Wolf 2014-02-02 22:11:08 +01:00
parent bee4450c4c
commit 9d0b69edaa
2 changed files with 47 additions and 7 deletions
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32
passes/opt/opt_const.cc
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@ -42,7 +42,7 @@ void replace_cell(RTLIL::Module *module, RTLIL::Cell *cell, std::string info, st
did_something = true;
}
void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef)
void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool consume_x, bool mux_undef, bool mux_bool)
{
if (!design->selected(module))
return;
@ -244,6 +244,24 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
}
}
if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(0, 1) && cell->connections["\\B"] == RTLIL::SigSpec(1, 1)) {
replace_cell(module, cell, "mux_bool", "\\Y", cell->connections["\\S"]);
goto next_cell;
}
if (mux_bool && cell->type == "$mux" && cell->connections["\\A"] == RTLIL::SigSpec(1, 1) && cell->connections["\\B"] == RTLIL::SigSpec(0, 1)) {
cell->connections["\\A"] = cell->connections["\\S"];
cell->connections.erase("\\B");
cell->connections.erase("\\S");
cell->parameters["\\A_WIDTH"] = cell->parameters["\\WIDTH"];
cell->parameters["\\Y_WIDTH"] = cell->parameters["\\WIDTH"];
cell->parameters["\\A_SIGNED"] = 0;
cell->parameters.erase("\\WIDTH");
cell->type = "$not";
did_something = true;
goto next_cell;
}
if (mux_undef && (cell->type == "$mux" || cell->type == "$pmux")) {
RTLIL::SigSpec new_a, new_b, new_s;
int width = cell->connections.at("\\A").width;
@ -392,10 +410,14 @@ struct OptConstPass : public Pass {
log(" -mux_undef\n");
log(" remove 'undef' inputs from $mux, $pmux and $_MUX_ cells\n");
log("\n");
log(" -mux_bool\n");
log(" replace $mux cells with inverters or buffers when possible\n");
log("\n");
}
virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
{
bool mux_undef = false;
bool mux_bool = false;
log_header("Executing OPT_CONST pass (perform const folding).\n");
log_push();
@ -406,6 +428,10 @@ struct OptConstPass : public Pass {
mux_undef = true;
continue;
}
if (args[argidx] == "-mux_bool") {
mux_bool = true;
continue;
}
break;
}
extra_args(args, argidx, design);
@ -414,9 +440,9 @@ struct OptConstPass : public Pass {
do {
do {
did_something = false;
replace_const_cells(design, mod_it.second, false, mux_undef);
replace_const_cells(design, mod_it.second, false, mux_undef, mux_bool);
} while (did_something);
replace_const_cells(design, mod_it.second, true, mux_undef);
replace_const_cells(design, mod_it.second, true, mux_undef, mux_bool);
} while (did_something);
log_pop();