summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorClifford Wolf <clifford@clifford.at>2015-01-18 11:17:56 +0100
committerClifford Wolf <clifford@clifford.at>2015-01-18 11:17:56 +0100
commit61192514e3e22e196e1df5aaaf98bb2ed6fd57df (patch)
tree15a9245e2f1885094b4e9933071fcc2be2b42a18
parent279a18c9a39fc57bfdd295511672abf49bb563ac (diff)
Various cleanups and improvements in opt_muxtree
-rw-r--r--passes/opt/opt_muxtree.cc158
1 files changed, 71 insertions, 87 deletions
diff --git a/passes/opt/opt_muxtree.cc b/passes/opt/opt_muxtree.cc
index 33dd12a0..5a88b5a1 100644
--- a/passes/opt/opt_muxtree.cc
+++ b/passes/opt/opt_muxtree.cc
@@ -37,39 +37,33 @@ struct OptMuxtreeWorker
SigMap assign_map;
int removed_count;
- struct bitDef_t : public std::pair<RTLIL::Wire*, int> {
- bitDef_t() : std::pair<RTLIL::Wire*, int>(NULL, 0) { }
- bitDef_t(const RTLIL::SigBit &bit) : std::pair<RTLIL::Wire*, int>(bit.wire, bit.offset) { }
- };
-
-
struct bitinfo_t {
int num;
- bitDef_t bit;
+ SigBit bit;
bool seen_non_mux;
- std::vector<int> mux_users;
- std::vector<int> mux_drivers;
+ vector<int> mux_users;
+ vector<int> mux_drivers;
};
- std::map<bitDef_t, int> bit2num;
- std::vector<bitinfo_t> bit2info;
+ dict<SigBit, int> bit2num;
+ vector<bitinfo_t> bit2info;
struct portinfo_t {
- std::vector<int> ctrl_sigs;
- std::vector<int> input_sigs;
- std::vector<int> input_muxes;
+ int ctrl_sig;
+ vector<int> input_sigs;
+ vector<int> input_muxes;
bool const_activated;
+ bool const_deactivated;
bool enabled;
};
struct muxinfo_t {
RTLIL::Cell *cell;
- std::vector<portinfo_t> ports;
+ vector<portinfo_t> ports;
};
- std::vector<muxinfo_t> mux2info;
-
- std::set<int> root_muxes;
+ vector<muxinfo_t> mux2info;
+ vector<bool> root_muxes;
OptMuxtreeWorker(RTLIL::Design *design, RTLIL::Module *module) :
design(design), module(module), assign_map(module), removed_count(0)
@@ -83,9 +77,10 @@ struct OptMuxtreeWorker
// .mux_users
// .mux_drivers
// Populate mux2info[].ports[]:
- // .ctrl_sigs
+ // .ctrl_sig
// .input_sigs
// .const_activated
+ // .const_deactivated
for (auto cell : module->cells())
{
if (cell->type == "$mux" || cell->type == "$pmux")
@@ -102,13 +97,13 @@ struct OptMuxtreeWorker
RTLIL::SigSpec sig = sig_b.extract(i*sig_a.size(), sig_a.size());
RTLIL::SigSpec ctrl_sig = assign_map(sig_s.extract(i, 1));
portinfo_t portinfo;
+ portinfo.ctrl_sig = sig2bits(ctrl_sig, false).front();
for (int idx : sig2bits(sig)) {
add_to_list(bit2info[idx].mux_users, mux2info.size());
add_to_list(portinfo.input_sigs, idx);
}
- for (int idx : sig2bits(ctrl_sig))
- add_to_list(portinfo.ctrl_sigs, idx);
portinfo.const_activated = ctrl_sig.is_fully_const() && ctrl_sig.as_bool();
+ portinfo.const_deactivated = ctrl_sig.is_fully_const() && !ctrl_sig.as_bool();
portinfo.enabled = false;
muxinfo.ports.push_back(portinfo);
}
@@ -118,7 +113,9 @@ struct OptMuxtreeWorker
add_to_list(bit2info[idx].mux_users, mux2info.size());
add_to_list(portinfo.input_sigs, idx);
}
+ portinfo.ctrl_sig = -1;
portinfo.const_activated = false;
+ portinfo.const_deactivated = false;
portinfo.enabled = false;
muxinfo.ports.push_back(portinfo);
@@ -162,6 +159,7 @@ struct OptMuxtreeWorker
log(" Evaluating internal representation of mux trees.\n");
dict<int, pool<int>> mux_to_users;
+ root_muxes.resize(mux2info.size());
for (auto &bi : bit2info) {
for (int i : bi.mux_drivers)
@@ -170,23 +168,24 @@ struct OptMuxtreeWorker
if (!bi.seen_non_mux)
continue;
for (int mux_idx : bi.mux_drivers)
- root_muxes.insert(mux_idx);
+ root_muxes.at(mux_idx) = true;
}
for (auto &it : mux_to_users)
if (GetSize(it.second) > 1)
- root_muxes.insert(it.first);
+ root_muxes.at(it.first) = true;
- for (int mux_idx : root_muxes) {
- log(" Root of a mux tree: %s\n", log_id(mux2info[mux_idx].cell));
- eval_root_mux(mux_idx);
- }
+ for (int mux_idx = 0; mux_idx < GetSize(root_muxes); mux_idx++)
+ if (root_muxes.at(mux_idx)) {
+ log(" Root of a mux tree: %s\n", log_id(mux2info[mux_idx].cell));
+ eval_root_mux(mux_idx);
+ }
log(" Analyzing evaluation results.\n");
for (auto &mi : mux2info)
{
- std::vector<int> live_ports;
+ vector<int> live_ports;
for (int port_idx = 0; port_idx < GetSize(mi.ports); port_idx++) {
portinfo_t &pi = mi.ports[port_idx];
if (pi.enabled) {
@@ -247,15 +246,7 @@ struct OptMuxtreeWorker
}
}
- bool list_is_subset(const std::vector<int> &sub, const std::vector<int> &super)
- {
- for (int v : sub)
- if (!is_in_list(super, v))
- return false;
- return true;
- }
-
- bool is_in_list(const std::vector<int> &list, int value)
+ bool is_in_list(const vector<int> &list, int value)
{
for (int v : list)
if (v == value)
@@ -263,15 +254,15 @@ struct OptMuxtreeWorker
return false;
}
- void add_to_list(std::vector<int> &list, int value)
+ void add_to_list(vector<int> &list, int value)
{
if (!is_in_list(list, value))
list.push_back(value);
}
- std::vector<int> sig2bits(RTLIL::SigSpec sig, bool skip_non_wires = true)
+ vector<int> sig2bits(RTLIL::SigSpec sig, bool skip_non_wires = true)
{
- std::vector<int> results;
+ vector<int> results;
assign_map.apply(sig);
for (auto &bit : sig)
if (bit.wire != NULL) {
@@ -292,57 +283,58 @@ struct OptMuxtreeWorker
struct knowledge_t
{
// database of known inactive signals
- // the 2nd integer is a reference counter used to manage the
+ // the payload is a reference counter used to manage the
// list. when it is non-zero the signal in known to be inactive
- std::map<int, int> known_inactive;
+ vector<int> known_inactive;
// database of known active signals
- // the 2nd dimension is the list of or-ed signals. so we know that
- // for each i there is a j so that known_active[i][j] points to an
- // active control signal.
- std::vector<std::vector<int>> known_active;
+ vector<int> known_active;
// this is just used to keep track of visited muxes in order to prohibit
// endless recursion in mux loops
- std::set<int> visited_muxes;
+ vector<bool> visited_muxes;
};
void eval_mux_port(knowledge_t &knowledge, int mux_idx, int port_idx)
{
muxinfo_t &muxinfo = mux2info[mux_idx];
+
+ if (muxinfo.ports[port_idx].const_deactivated)
+ return;
+
muxinfo.ports[port_idx].enabled = true;
- for (size_t i = 0; i < muxinfo.ports.size(); i++) {
- if (int(i) == port_idx)
+ for (int i = 0; i < GetSize(muxinfo.ports); i++) {
+ if (i == port_idx)
continue;
- for (int b : muxinfo.ports[i].ctrl_sigs)
- knowledge.known_inactive[b]++;
+ if (muxinfo.ports[i].ctrl_sig >= 0)
+ knowledge.known_inactive.at(muxinfo.ports[i].ctrl_sig)++;
}
if (port_idx < int(muxinfo.ports.size())-1 && !muxinfo.ports[port_idx].const_activated)
- knowledge.known_active.push_back(muxinfo.ports[port_idx].ctrl_sigs);
+ knowledge.known_active.at(muxinfo.ports[port_idx].ctrl_sig)++;
- std::vector<int> parent_muxes;
+ vector<int> parent_muxes;
for (int m : muxinfo.ports[port_idx].input_muxes) {
- if (knowledge.visited_muxes.count(m) > 0)
+ if (knowledge.visited_muxes[m])
continue;
- knowledge.visited_muxes.insert(m);
+ knowledge.visited_muxes[m] = true;
parent_muxes.push_back(m);
}
for (int m : parent_muxes)
- if (!root_muxes.count(m))
+ if (!root_muxes.at(m))
eval_mux(knowledge, m);
for (int m : parent_muxes)
- knowledge.visited_muxes.erase(m);
+ knowledge.visited_muxes[m] = false;
if (port_idx < int(muxinfo.ports.size())-1 && !muxinfo.ports[port_idx].const_activated)
- knowledge.known_active.pop_back();
+ knowledge.known_active.at(muxinfo.ports[port_idx].ctrl_sig)--;
for (size_t i = 0; i < muxinfo.ports.size(); i++) {
if (int(i) == port_idx)
continue;
- for (int b : muxinfo.ports[i].ctrl_sigs)
- knowledge.known_inactive[b]--;
+ if (muxinfo.ports[i].ctrl_sig >= 0)
+ knowledge.known_inactive.at(muxinfo.ports[i].ctrl_sig)--;
}
}
@@ -351,20 +343,17 @@ struct OptMuxtreeWorker
SigSpec sig = muxinfo.cell->getPort(portname);
bool did_something = false;
- std::vector<int> bits = sig2bits(sig, false);
+ vector<int> bits = sig2bits(sig, false);
for (int i = 0; i < GetSize(bits); i++) {
if (bits[i] < 0)
continue;
- if (knowledge.known_inactive[bits[i]]) {
+ if (knowledge.known_inactive.at(bits[i])) {
sig[i] = State::S0;
did_something = true;
- } else {
- for (auto &it : knowledge.known_active)
- if (GetSize(it) == 1 && it.front() == bits[i]) {
- sig[i] = State::S1;
- did_something = true;
- break;
- }
+ } else
+ if (knowledge.known_active.at(bits[i])) {
+ sig[i] = State::S1;
+ did_something = true;
}
}
@@ -399,16 +388,14 @@ struct OptMuxtreeWorker
for (size_t port_idx = 0; port_idx < muxinfo.ports.size()-1; port_idx++)
{
portinfo_t &portinfo = muxinfo.ports[port_idx];
- for (size_t i = 0; i < knowledge.known_active.size(); i++) {
- if (list_is_subset(knowledge.known_active[i], portinfo.ctrl_sigs)) {
- eval_mux_port(knowledge, mux_idx, port_idx);
- return;
- }
+ if (knowledge.known_active.at(portinfo.ctrl_sig)) {
+ eval_mux_port(knowledge, mux_idx, port_idx);
+ return;
}
}
- // compare ports with known_inactive and known_active signals. If all control
- // signals of the port are known_inactive or if the control signals of all other
+ // compare ports with known_inactive and known_active signals. If the control
+ // signal of the port is known_inactive or if the control signals of all other
// ports are known_active this port can't be activated. this loop includes the
// default port but no known_inactive match is performed on the default port.
for (size_t port_idx = 0; port_idx < muxinfo.ports.size(); port_idx++)
@@ -417,23 +404,17 @@ struct OptMuxtreeWorker
if (port_idx < muxinfo.ports.size()-1) {
bool found_non_known_inactive = false;
- for (int i : portinfo.ctrl_sigs)
- if (knowledge.known_inactive[i] == 0)
- found_non_known_inactive = true;
+ if (knowledge.known_inactive.at(portinfo.ctrl_sig) == 0)
+ found_non_known_inactive = true;
if (!found_non_known_inactive)
continue;
}
bool port_active = true;
- std::vector<int> other_ctrl_sig;
for (size_t i = 0; i < muxinfo.ports.size()-1; i++) {
if (i == port_idx)
continue;
- other_ctrl_sig.insert(other_ctrl_sig.end(),
- muxinfo.ports[i].ctrl_sigs.begin(), muxinfo.ports[i].ctrl_sigs.end());
- }
- for (size_t i = 0; i < knowledge.known_active.size(); i++) {
- if (list_is_subset(knowledge.known_active[i], other_ctrl_sig))
+ if (knowledge.known_active.at(muxinfo.ports[i].ctrl_sig))
port_active = false;
}
if (port_active)
@@ -444,7 +425,10 @@ struct OptMuxtreeWorker
void eval_root_mux(int mux_idx)
{
knowledge_t knowledge;
- knowledge.visited_muxes.insert(mux_idx);
+ knowledge.known_inactive.resize(bit2info.size());
+ knowledge.known_active.resize(bit2info.size());
+ knowledge.visited_muxes.resize(mux2info.size());
+ knowledge.visited_muxes[mux_idx] = true;
eval_mux(knowledge, mux_idx);
}
};
@@ -464,7 +448,7 @@ struct OptMuxtreePass : public Pass {
log("This pass only operates on completely selected modules without processes.\n");
log("\n");
}
- virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+ virtual void execute(vector<std::string> args, RTLIL::Design *design)
{
log_header("Executing OPT_MUXTREE pass (detect dead branches in mux trees).\n");
extra_args(args, 1, design);