diff options
| -rw-r--r-- | backends/cxxrtl/cxxrtl_vcd.h | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/backends/cxxrtl/cxxrtl_vcd.h b/backends/cxxrtl/cxxrtl_vcd.h index 8ba94ea77..5f5f612b5 100644 --- a/backends/cxxrtl/cxxrtl_vcd.h +++ b/backends/cxxrtl/cxxrtl_vcd.h @@ -104,19 +104,25 @@ class vcd_writer { buffer += '\n'; } - const variable ®ister_variable(size_t width, chunk_t *curr) { + 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(); - variables.emplace_back(variable { variables.size(), width, curr, cache.size() }); - cache.insert(cache.end(), &curr[0], &curr[chunks]); + 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; @@ -158,7 +164,7 @@ public: switch (item.type) { // Not the best naming but oh well... case debug_item::VALUE: - emit_var(register_variable(item.width, item.curr), "wire", name); + 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); |