verilator/include/verilated_fst_c.cpp
Geza Lore b51f887567
Perform VCD tracing in parallel when using --threads (#3449)
VCD tracing is now parallelized using the same thread pool as the model.
We achieve this by breaking the top level trace functions into multiple
top level functions (as many as --threads), and after emitting the time
stamp to the VCD file on the main thread, we execute the tracing
functions in parallel on the same thread pool as the model (which we
pass to the trace file during registration), tracing into a secondary
per thread buffer. The main thread will then stitch (memcpy) the buffers
together into the output file.

This makes the `--trace-threads` option redundant with `--trace`, which
now only affects `--trace-fst`. FST tracing uses the previous offloading
scheme.

This obviously helps a lot in VCD tracing performance, and I have seen
better than Amdahl speedup, namely I get 3.9x on XiangShan 4T (2.7x on
OpenTitan 4T).
2022-05-29 19:08:39 +01:00

336 lines
13 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//=============================================================================
//
// Code available from: https://verilator.org
//
// Copyright 2001-2022 by Wilson Snyder. This program is free software; you
// can redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//=============================================================================
///
/// \file
/// \brief Verilated C++ tracing in FST format implementation code
///
/// This file must be compiled and linked against all Verilated objects
/// that use --trace-fst.
///
/// Use "verilator --trace-fst" to add this to the Makefile for the linker.
///
//=============================================================================
// clang-format off
#define __STDC_LIMIT_MACROS // UINT64_MAX
#include "verilated.h"
#include "verilated_fst_c.h"
// GTKWave configuration
#ifdef VL_TRACE_FST_WRITER_THREAD
# define HAVE_LIBPTHREAD
# define FST_WRITER_PARALLEL
#endif
// Include the GTKWave implementation directly
#define FST_CONFIG_INCLUDE "fst_config.h"
#include "gtkwave/fastlz.c"
#include "gtkwave/fstapi.c"
#include "gtkwave/lz4.c"
#include <algorithm>
#include <iterator>
#include <sstream>
#if defined(_WIN32) && !defined(__MINGW32__) && !defined(__CYGWIN__)
# include <io.h>
#else
# include <unistd.h>
#endif
// clang-format on
//=============================================================================
// Check that vltscope_t matches fstScopeType
static_assert(static_cast<int>(FST_ST_VCD_MODULE) == static_cast<int>(VLT_TRACE_SCOPE_MODULE),
"VLT_TRACE_SCOPE_MODULE mismatches");
static_assert(static_cast<int>(FST_ST_VCD_TASK) == static_cast<int>(VLT_TRACE_SCOPE_TASK),
"VLT_TRACE_SCOPE_TASK mismatches");
static_assert(static_cast<int>(FST_ST_VCD_FUNCTION) == static_cast<int>(VLT_TRACE_SCOPE_FUNCTION),
"VLT_TRACE_SCOPE_FUNCTION mismatches");
static_assert(static_cast<int>(FST_ST_VCD_BEGIN) == static_cast<int>(VLT_TRACE_SCOPE_BEGIN),
"VLT_TRACE_SCOPE_BEGIN mismatches");
static_assert(static_cast<int>(FST_ST_VCD_FORK) == static_cast<int>(VLT_TRACE_SCOPE_FORK),
"VLT_TRACE_SCOPE_FORK mismatches");
static_assert(static_cast<int>(FST_ST_VCD_GENERATE) == static_cast<int>(VLT_TRACE_SCOPE_GENERATE),
"VLT_TRACE_SCOPE_GENERATE mismatches");
static_assert(static_cast<int>(FST_ST_VCD_STRUCT) == static_cast<int>(VLT_TRACE_SCOPE_STRUCT),
"VLT_TRACE_SCOPE_STRUCT mismatches");
static_assert(static_cast<int>(FST_ST_VCD_UNION) == static_cast<int>(VLT_TRACE_SCOPE_UNION),
"VLT_TRACE_SCOPE_UNION mismatches");
static_assert(static_cast<int>(FST_ST_VCD_CLASS) == static_cast<int>(VLT_TRACE_SCOPE_CLASS),
"VLT_TRACE_SCOPE_CLASS mismatches");
static_assert(static_cast<int>(FST_ST_VCD_INTERFACE)
== static_cast<int>(VLT_TRACE_SCOPE_INTERFACE),
"VLT_TRACE_SCOPE_INTERFACE mismatches");
static_assert(static_cast<int>(FST_ST_VCD_PACKAGE) == static_cast<int>(VLT_TRACE_SCOPE_PACKAGE),
"VLT_TRACE_SCOPE_PACKAGE mismatches");
static_assert(static_cast<int>(FST_ST_VCD_PROGRAM) == static_cast<int>(VLT_TRACE_SCOPE_PROGRAM),
"VLT_TRACE_SCOPE_PROGRAM mismatches");
//=============================================================================
// Specialization of the generics for this trace format
#define VL_SUB_T VerilatedFst
#define VL_BUF_T VerilatedFstBuffer
#include "verilated_trace_imp.h"
#undef VL_SUB_T
#undef VL_BUF_T
//=============================================================================
// VerilatedFst
VerilatedFst::VerilatedFst(void* fst)
: m_fst{fst} {}
VerilatedFst::~VerilatedFst() {
if (m_fst) fstWriterClose(m_fst);
if (m_symbolp) VL_DO_CLEAR(delete[] m_symbolp, m_symbolp = nullptr);
if (m_strbuf) VL_DO_CLEAR(delete[] m_strbuf, m_strbuf = nullptr);
}
void VerilatedFst::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {
const VerilatedLockGuard lock{m_mutex};
m_fst = fstWriterCreate(filename, 1);
fstWriterSetPackType(m_fst, FST_WR_PT_LZ4);
fstWriterSetTimescaleFromString(m_fst, timeResStr().c_str()); // lintok-begin-on-ref
#ifdef VL_TRACE_FST_WRITER_THREAD
fstWriterSetParallelMode(m_fst, 1);
#endif
fullDump(true); // First dump must be full for fst
m_curScope.clear();
Super::traceInit();
// Clear the scope stack
auto it = m_curScope.begin();
while (it != m_curScope.end()) {
fstWriterSetUpscope(m_fst);
it = m_curScope.erase(it);
}
// convert m_code2symbol into an array for fast lookup
if (!m_symbolp) {
m_symbolp = new fstHandle[nextCode()]{0};
for (const auto& i : m_code2symbol) m_symbolp[i.first] = i.second;
}
m_code2symbol.clear();
// Allocate string buffer for arrays
if (!m_strbuf) m_strbuf = new char[maxBits() + 32];
}
void VerilatedFst::close() VL_MT_SAFE_EXCLUDES(m_mutex) {
const VerilatedLockGuard lock{m_mutex};
Super::closeBase();
fstWriterClose(m_fst);
m_fst = nullptr;
}
void VerilatedFst::flush() VL_MT_SAFE_EXCLUDES(m_mutex) {
const VerilatedLockGuard lock{m_mutex};
Super::flushBase();
fstWriterFlushContext(m_fst);
}
void VerilatedFst::emitTimeChange(uint64_t timeui) { fstWriterEmitTimeChange(m_fst, timeui); }
//=============================================================================
// Decl
void VerilatedFst::declDTypeEnum(int dtypenum, const char* name, uint32_t elements,
unsigned int minValbits, const char** itemNamesp,
const char** itemValuesp) {
const fstEnumHandle enumNum
= fstWriterCreateEnumTable(m_fst, name, elements, minValbits, itemNamesp, itemValuesp);
m_local2fstdtype[dtypenum] = enumNum;
}
void VerilatedFst::declare(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum, bool bussed, int msb,
int lsb) {
const int bits = ((msb > lsb) ? (msb - lsb) : (lsb - msb)) + 1;
const bool enabled = Super::declCode(code, name, bits, false);
if (!enabled) return;
std::string nameasstr = namePrefix() + name;
std::istringstream nameiss{nameasstr};
std::istream_iterator<std::string> beg(nameiss);
std::istream_iterator<std::string> end;
std::list<std::string> tokens(beg, end); // Split name
std::string symbol_name{tokens.back()};
tokens.pop_back(); // Remove symbol name from hierarchy
std::string tmpModName;
// Find point where current and new scope diverge
auto cur_it = m_curScope.begin();
auto new_it = tokens.begin();
while (cur_it != m_curScope.end() && new_it != tokens.end()) {
if (*cur_it != *new_it) break;
++cur_it;
++new_it;
}
// Go back to the common point
while (cur_it != m_curScope.end()) {
fstWriterSetUpscope(m_fst);
cur_it = m_curScope.erase(cur_it);
}
// Follow the hierarchy of the new variable from the common scope point
while (new_it != tokens.end()) {
if ((new_it->back() & 0x80)) {
tmpModName = *new_it;
tmpModName.pop_back();
// If the scope ends with a non-ascii character, it will be 0x80 + fstScopeType
fstWriterSetScope(m_fst, static_cast<fstScopeType>(new_it->back() & 0x7f),
tmpModName.c_str(), nullptr);
} else {
fstWriterSetScope(m_fst, FST_ST_VCD_SCOPE, new_it->c_str(), nullptr);
}
m_curScope.push_back(*new_it);
new_it = tokens.erase(new_it);
}
std::stringstream name_ss;
name_ss << symbol_name;
if (array) name_ss << "[" << arraynum << "]";
if (bussed) name_ss << " [" << msb << ":" << lsb << "]";
std::string name_str = name_ss.str();
if (dtypenum > 0) {
const fstEnumHandle enumNum = m_local2fstdtype[dtypenum];
fstWriterEmitEnumTableRef(m_fst, enumNum);
}
const auto it = vlstd::as_const(m_code2symbol).find(code);
if (it == m_code2symbol.end()) { // New
m_code2symbol[code]
= fstWriterCreateVar(m_fst, vartype, vardir, bits, name_str.c_str(), 0);
} else { // Alias
fstWriterCreateVar(m_fst, vartype, vardir, bits, name_str.c_str(), it->second);
}
}
void VerilatedFst::declBit(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum) {
declare(code, name, dtypenum, vardir, vartype, array, arraynum, false, 0, 0);
}
void VerilatedFst::declBus(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
}
void VerilatedFst::declQuad(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
}
void VerilatedFst::declArray(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
}
void VerilatedFst::declDouble(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
fstVarType vartype, bool array, int arraynum) {
declare(code, name, dtypenum, vardir, vartype, array, arraynum, false, 63, 0);
}
//=============================================================================
// Get/commit trace buffer
VerilatedFstBuffer* VerilatedFst::getTraceBuffer() { return new VerilatedFstBuffer{*this}; }
void VerilatedFst::commitTraceBuffer(VerilatedFstBuffer* bufp) {
#ifdef VL_TRACE_OFFLOAD
if (bufp->m_offloadBufferWritep) {
m_offloadBufferWritep = bufp->m_offloadBufferWritep;
return; // Buffer will be deleted by the offload thread
}
#endif
delete bufp;
}
//=============================================================================
// VerilatedFstBuffer implementation
VerilatedFstBuffer::VerilatedFstBuffer(VerilatedFst& owner)
: VerilatedTraceBuffer<VerilatedFst, VerilatedFstBuffer>{owner} {}
//=============================================================================
// Trace rendering primitives
// Note: emit* are only ever called from one place (full* in
// verilated_trace_imp.h, which is included in this file at the top),
// so always inline them.
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitBit(uint32_t code, CData newval) {
VL_DEBUG_IFDEF(assert(m_symbolp[code]););
fstWriterEmitValueChange(m_fst, m_symbolp[code], newval ? "1" : "0");
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitCData(uint32_t code, CData newval, int bits) {
char buf[VL_BYTESIZE];
VL_DEBUG_IFDEF(assert(m_symbolp[code]););
cvtCDataToStr(buf, newval << (VL_BYTESIZE - bits));
fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitSData(uint32_t code, SData newval, int bits) {
char buf[VL_SHORTSIZE];
VL_DEBUG_IFDEF(assert(m_symbolp[code]););
cvtSDataToStr(buf, newval << (VL_SHORTSIZE - bits));
fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitIData(uint32_t code, IData newval, int bits) {
char buf[VL_IDATASIZE];
VL_DEBUG_IFDEF(assert(m_symbolp[code]););
cvtIDataToStr(buf, newval << (VL_IDATASIZE - bits));
fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitQData(uint32_t code, QData newval, int bits) {
char buf[VL_QUADSIZE];
VL_DEBUG_IFDEF(assert(m_symbolp[code]););
cvtQDataToStr(buf, newval << (VL_QUADSIZE - bits));
fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitWData(uint32_t code, const WData* newvalp, int bits) {
int words = VL_WORDS_I(bits);
char* wp = m_strbuf;
// Convert the most significant word
const int bitsInMSW = VL_BITBIT_E(bits) ? VL_BITBIT_E(bits) : VL_EDATASIZE;
cvtEDataToStr(wp, newvalp[--words] << (VL_EDATASIZE - bitsInMSW));
wp += bitsInMSW;
// Convert the remaining words
while (words > 0) {
cvtEDataToStr(wp, newvalp[--words]);
wp += VL_EDATASIZE;
}
fstWriterEmitValueChange(m_fst, m_symbolp[code], m_strbuf);
}
VL_ATTR_ALWINLINE
void VerilatedFstBuffer::emitDouble(uint32_t code, double newval) {
fstWriterEmitValueChange(m_fst, m_symbolp[code], &newval);
}