diff options
Diffstat (limited to 'passes/proc/proc_clean.cc')
| -rw-r--r-- | passes/proc/proc_clean.cc | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/passes/proc/proc_clean.cc b/passes/proc/proc_clean.cc new file mode 100644 index 00000000..ec9fade3 --- /dev/null +++ b/passes/proc/proc_clean.cc @@ -0,0 +1,160 @@ +/* + * yosys -- Yosys Open SYnthesis Suite + * + * Copyright (C) 2012 Clifford Wolf <clifford@clifford.at> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#include "kernel/register.h" +#include "kernel/log.h" +#include <stdlib.h> +#include <stdio.h> + +static void switch_clean(RTLIL::SwitchRule *sw, RTLIL::CaseRule *parent, bool &did_something, int &count); +static void case_clean(RTLIL::CaseRule *cs, bool &did_something, int &count); + +static void switch_clean(RTLIL::SwitchRule *sw, RTLIL::CaseRule *parent, bool &did_something, int &count) +{ + if (sw->signal.width > 0 && sw->signal.is_fully_const()) + { + int found_matching_case_idx = -1; + for (int i = 0; i < int(sw->cases.size()) && found_matching_case_idx < 0; i++) + { + RTLIL::CaseRule *cs = sw->cases[i]; + if (cs->compare.size() == 0) + break; + for (int j = 0; j < int(cs->compare.size()); j++) { + RTLIL::SigSpec &val = cs->compare[j]; + if (!val.is_fully_const()) + continue; + if (val == sw->signal) { + cs->compare.clear(); + found_matching_case_idx = i; + break; + } else + cs->compare.erase(cs->compare.begin()+(j--)); + } + if (cs->compare.size() == 0 && found_matching_case_idx < 0) { + sw->cases.erase(sw->cases.begin()+(i--)); + delete cs; + } + } + while (found_matching_case_idx >= 0 && int(sw->cases.size()) > found_matching_case_idx+1) { + delete sw->cases.back(); + sw->cases.pop_back(); + } + if (found_matching_case_idx == 0) + sw->signal = RTLIL::SigSpec(); + } + + if (sw->cases.size() == 1 && (sw->signal.width == 0 || sw->cases[0]->compare.empty())) + { + did_something = true; + for (auto &action : sw->cases[0]->actions) + parent->actions.push_back(action); + for (auto sw2 : sw->cases[0]->switches) + parent->switches.push_back(sw2); + sw->cases[0]->switches.clear(); + delete sw->cases[0]; + sw->cases.clear(); + } + else + { + bool all_cases_are_empty = true; + for (auto cs : sw->cases) { + if (cs->actions.size() != 0 || cs->switches.size() != 0) + all_cases_are_empty = false; + case_clean(cs, did_something, count); + } + if (all_cases_are_empty) { + did_something = true; + for (auto cs : sw->cases) + delete cs; + sw->cases.clear(); + } + } +} + +static void case_clean(RTLIL::CaseRule *cs, bool &did_something, int &count) +{ + for (size_t i = 0; i < cs->actions.size(); i++) { + if (cs->actions[i].first.width == 0) { + did_something = true; + cs->actions.erase(cs->actions.begin() + (i--)); + } + } + for (size_t i = 0; i < cs->switches.size(); i++) { + RTLIL::SwitchRule *sw = cs->switches[i]; + if (sw->cases.size() == 0) { + cs->switches.erase(cs->switches.begin() + (i--)); + did_something = true; + delete sw; + count++; + } else + switch_clean(sw, cs, did_something, count); + } +} + +static void proc_clean(RTLIL::Module *mod, RTLIL::Process *proc, int &total_count) +{ + int count = 0; + bool did_something = true; + for (size_t i = 0; i < proc->syncs.size(); i++) { + for (size_t j = 0; j < proc->syncs[i]->actions.size(); j++) + if (proc->syncs[i]->actions[j].first.width == 0) + proc->syncs[i]->actions.erase(proc->syncs[i]->actions.begin() + (j--)); + if (proc->syncs[i]->actions.size() == 0) { + delete proc->syncs[i]; + proc->syncs.erase(proc->syncs.begin() + (i--)); + } + } + while (did_something) { + did_something = false; + case_clean(&proc->root_case, did_something, count); + } + if (count > 0) + log("Found and cleaned up %d empty switch%s in `%s.%s'.\n", count, count == 1 ? "" : "es", mod->name.c_str(), proc->name.c_str()); + total_count += count; +} + +struct ProcCleanPass : public Pass { + ProcCleanPass() : Pass("proc_clean") { } + virtual void execute(std::vector<std::string> args, RTLIL::Design *design) + { + int total_count = 0; + log_header("Executing PROC_CLEAN pass (remove empty switches from decision trees).\n"); + + extra_args(args, 1, design); + + for (auto &mod_it : design->modules) { + std::vector<std::string> delme; + for (auto &proc_it : mod_it.second->processes) { + proc_clean(mod_it.second, proc_it.second, total_count); + if (proc_it.second->syncs.size() == 0 && proc_it.second->root_case.switches.size() == 0 && + proc_it.second->root_case.actions.size() == 0) { + log("Removing empty process `%s.%s'.\n", mod_it.first.c_str(), proc_it.second->name.c_str()); + delme.push_back(proc_it.first); + } + } + for (auto &id : delme) { + delete mod_it.second->processes[id]; + mod_it.second->processes.erase(id); + } + } + + log("Cleaned up %d empty switch%s.\n", total_count, total_count == 1 ? "" : "es"); + } +} ProcCleanPass; + |