yosys/passes/proc/proc_clean.cc

237 lines
6.9 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Claire Xenia Wolf <claire@yosyshq.com>
*
* 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>
YOSYS_NAMESPACE_BEGIN
extern void proc_clean_case(RTLIL::CaseRule *cs, bool &did_something, int &count, int max_depth);
YOSYS_NAMESPACE_END
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
void proc_clean_switch(RTLIL::SwitchRule *sw, RTLIL::CaseRule *parent, bool &did_something, int &count, int max_depth)
{
if (sw->signal.size() > 0 && sw->signal.is_fully_def())
{
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_def())
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 (parent->switches.front() == sw && sw->cases.size() == 1 &&
(sw->signal.size() == 0 || sw->cases[0]->compare.empty()))
{
did_something = true;
for (auto &action : sw->cases[0]->actions)
parent->actions.push_back(action);
parent->switches.insert(parent->switches.begin(), sw->cases[0]->switches.begin(), sw->cases[0]->switches.end());
sw->cases[0]->switches.clear();
delete sw->cases[0];
sw->cases.clear();
}
else
{
for (auto cs : sw->cases)
if (max_depth != 0)
proc_clean_case(cs, did_something, count, max_depth-1);
bool is_parallel_case = sw->get_bool_attribute(ID::parallel_case);
bool is_full_case = sw->get_bool_attribute(ID::full_case);
// Empty case removal. The rules are:
//
// - for full_case: only remove cases if *all* cases are empty
// - for parallel_case but not full_case: remove any empty case
// - for non-parallel and non-full case: remove the final case if it's empty
if (is_full_case)
{
bool all_empty = true;
for (auto cs : sw->cases)
if (!cs->empty())
all_empty = false;
if (all_empty)
{
for (auto cs : sw->cases)
delete cs;
sw->cases.clear();
}
}
else if (is_parallel_case)
{
for (auto cs = sw->cases.begin(); cs != sw->cases.end();)
{
if ((*cs)->empty())
{
did_something = true;
delete *cs;
cs = sw->cases.erase(cs);
}
else ++cs;
}
}
else
{
while (!sw->cases.empty() && sw->cases.back()->empty())
{
did_something = true;
delete sw->cases.back();
sw->cases.pop_back();
}
}
}
}
PRIVATE_NAMESPACE_END
YOSYS_NAMESPACE_BEGIN
void proc_clean_case(RTLIL::CaseRule *cs, bool &did_something, int &count, int max_depth)
{
for (size_t i = 0; i < cs->actions.size(); i++) {
if (cs->actions[i].first.size() == 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->empty()) {
cs->switches.erase(cs->switches.begin() + (i--));
did_something = true;
delete sw;
count++;
} else if (max_depth != 0)
proc_clean_switch(sw, cs, did_something, count, max_depth-1);
}
}
YOSYS_NAMESPACE_END
PRIVATE_NAMESPACE_BEGIN
void proc_clean(RTLIL::Module *mod, RTLIL::Process *proc, int &total_count, bool quiet)
{
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.size() == 0)
proc->syncs[i]->actions.erase(proc->syncs[i]->actions.begin() + (j--));
if (proc->syncs[i]->actions.size() == 0 && proc->syncs[i]->mem_write_actions.size() == 0) {
delete proc->syncs[i];
proc->syncs.erase(proc->syncs.begin() + (i--));
}
}
while (did_something) {
did_something = false;
proc_clean_case(&proc->root_case, did_something, count, -1);
}
if (count > 0 && !quiet)
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", "remove empty parts of processes") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" proc_clean [options] [selection]\n");
log("\n");
log(" -quiet\n");
log(" do not print any messages.\n");
log("\n");
log("This pass removes empty parts of processes and ultimately removes a process\n");
log("if it contains only empty structures.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
int total_count = 0;
bool quiet = false;
if (find(args.begin(), args.end(), "-quiet") == args.end())
log_header(design, "Executing PROC_CLEAN pass (remove empty switches from decision trees).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
if (args[argidx] == "-quiet") {
quiet = true;
continue;
}
}
extra_args(args, argidx, design);
for (auto mod : design->modules()) {
std::vector<RTLIL::Process *> delme;
if (!design->selected(mod))
continue;
for (auto &proc_it : mod->processes) {
if (!design->selected(mod, proc_it.second))
continue;
proc_clean(mod, proc_it.second, total_count, quiet);
if (proc_it.second->syncs.size() == 0 && proc_it.second->root_case.switches.size() == 0 &&
proc_it.second->root_case.actions.size() == 0) {
if (!quiet)
log("Removing empty process `%s.%s'.\n", log_id(mod), proc_it.second->name.c_str());
delme.push_back(proc_it.second);
}
}
for (auto proc : delme) {
mod->remove(proc);
}
}
if (!quiet)
log("Cleaned up %d empty switch%s.\n", total_count, total_count == 1 ? "" : "es");
}
} ProcCleanPass;
PRIVATE_NAMESPACE_END