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/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2020 whitequark <whitequark@whitequark.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted.
*
* 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.
*
*/
#ifndef CXXRTL_VCD_H
#define CXXRTL_VCD_H
#include <backends/cxxrtl/cxxrtl.h>
namespace cxxrtl {
class vcd_writer {
struct variable {
size_t ident;
size_t width;
chunk_t *curr;
size_t prev_off;
};
std::vector<std::string> current_scope;
std::vector<variable> variables;
std::vector<chunk_t> cache;
std::map<chunk_t*, size_t> aliases;
bool streaming = false;
void emit_timescale(unsigned number, const std::string &unit) {
assert(!streaming);
assert(number == 1 || number == 10 || number == 100);
assert(unit == "s" || unit == "ms" || unit == "us" ||
unit == "ns" || unit == "ps" || unit == "fs");
buffer += "$timescale " + std::to_string(number) + " " + unit + " $end\n";
}
void emit_scope(const std::vector<std::string> &scope) {
assert(!streaming);
while (current_scope.size() > scope.size() ||
(current_scope.size() > 0 &&
current_scope[current_scope.size() - 1] != scope[current_scope.size() - 1])) {
buffer += "$upscope $end\n";
current_scope.pop_back();
}
while (current_scope.size() < scope.size()) {
buffer += "$scope module " + scope[current_scope.size()] + " $end\n";
current_scope.push_back(scope[current_scope.size()]);
}
}
void emit_ident(size_t ident) {
do {
buffer += '!' + ident % 94; // "base94"
ident /= 94;
} while (ident != 0);
}
void emit_var(const variable &var, const std::string &type, const std::string &name) {
assert(!streaming);
buffer += "$var " + type + " " + std::to_string(var.width) + " ";
emit_ident(var.ident);
buffer += " " + name + " $end\n";
}
void emit_enddefinitions() {
assert(!streaming);
buffer += "$enddefinitions $end\n";
streaming = true;
}
void emit_time(uint64_t timestamp) {
assert(streaming);
buffer += "#" + std::to_string(timestamp) + "\n";
}
void emit_scalar(const variable &var) {
assert(streaming);
assert(var.width == 1);
buffer += (*var.curr ? '1' : '0');
emit_ident(var.ident);
buffer += '\n';
}
void emit_vector(const variable &var) {
assert(streaming);
buffer += 'b';
for (size_t bit = var.width - 1; bit != (size_t)-1; bit--) {
bool bit_curr = var.curr[bit / (8 * sizeof(chunk_t))] & (1 << (bit % (8 * sizeof(chunk_t))));
buffer += (bit_curr ? '1' : '0');
}
buffer += ' ';
emit_ident(var.ident);
buffer += '\n';
}
const variable ®ister_variable(size_t width, chunk_t *curr, bool immutable = false) {
if (aliases.count(curr)) {
return variables[aliases[curr]];
} else {
const size_t chunks = (width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
aliases[curr] = variables.size();
if (immutable) {
variables.emplace_back(variable { variables.size(), width, curr, (size_t)-1 });
} else {
variables.emplace_back(variable { variables.size(), width, curr, cache.size() });
cache.insert(cache.end(), &curr[0], &curr[chunks]);
}
return variables.back();
}
}
bool test_variable(const variable &var) {
if (var.prev_off == (size_t)-1)
return false; // immutable
const size_t chunks = (var.width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
if (std::equal(&var.curr[0], &var.curr[chunks], &cache[var.prev_off])) {
return false;
} else {
std::copy(&var.curr[0], &var.curr[chunks], &cache[var.prev_off]);
return true;
}
}
static std::vector<std::string> split_hierarchy(const std::string &hier_name) {
std::vector<std::string> hierarchy;
size_t prev = 0;
while (true) {
size_t curr = hier_name.find_first_of(' ', prev);
if (curr == std::string::npos) {
hierarchy.push_back(hier_name.substr(prev));
break;
} else {
hierarchy.push_back(hier_name.substr(prev, curr - prev));
prev = curr + 1;
}
}
return hierarchy;
}
public:
std::string buffer;
void timescale(unsigned number, const std::string &unit) {
emit_timescale(number, unit);
}
void add(const std::string &hier_name, const debug_item &item) {
std::vector<std::string> scope = split_hierarchy(hier_name);
std::string name = scope.back();
scope.pop_back();
emit_scope(scope);
switch (item.type) {
// Not the best naming but oh well...
case debug_item::VALUE:
emit_var(register_variable(item.width, item.curr, /*immutable=*/item.next == nullptr), "wire", name);
break;
case debug_item::WIRE:
emit_var(register_variable(item.width, item.curr), "reg", name);
break;
case debug_item::MEMORY: {
const size_t stride = (item.width + (sizeof(chunk_t) * 8 - 1)) / (sizeof(chunk_t) * 8);
for (size_t index = 0; index < item.depth; index++) {
chunk_t *nth_curr = &item.curr[stride * index];
std::string nth_name = name + '[' + std::to_string(index) + ']';
emit_var(register_variable(item.width, nth_curr), "reg", nth_name);
}
break;
}
}
}
template<class Filter>
void add(const debug_items &items, const Filter &filter) {
// `debug_items` is a map, so the items are already sorted in an order optimal for emitting
// VCD scope sections.
for (auto &it : items)
if (filter(it.first, it.second))
add(it.first, it.second);
}
void add(const debug_items &items) {
this->template add(items, [](const std::string &, const debug_item &) {
return true;
});
}
void add_without_memories(const debug_items &items) {
this->template add(items, [](const std::string &, const debug_item &item) {
return item.type == debug_item::VALUE || item.type == debug_item::WIRE;
});
}
void sample(uint64_t timestamp) {
bool first_sample = !streaming;
if (first_sample) {
emit_scope({});
emit_enddefinitions();
}
emit_time(timestamp);
for (auto var : variables)
if (test_variable(var) || first_sample) {
if (var.width == 1)
emit_scalar(var);
else
emit_vector(var);
}
}
};
}
#endif
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