verilator/src/V3LinkLevel.cpp

255 lines
11 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Resolve module/signal name references
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2021 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
//
//*************************************************************************
// LINKTOP TRANSFORMATIONS:
// Utility functions
// Sort cells by depth
// Create new MODULE TOP with connections to below signals
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3LinkLevel.h"
#include "V3Ast.h"
#include <algorithm>
#include <map>
#include <vector>
//######################################################################
// Levelizing class functions
struct CmpLevel {
bool operator()(const AstNodeModule* lhsp, const AstNodeModule* rhsp) const {
return lhsp->level() < rhsp->level();
}
};
void V3LinkLevel::modSortByLevel() {
// Sort modules by levels, root down to lowest children
// Calculate levels again in case we added modules
UINFO(2, "modSortByLevel()\n");
// level() was computed for us in V3LinkCells
ModVec mods; // Modules
ModVec tops; // Top level modules
for (AstNodeModule* nodep = v3Global.rootp()->modulesp(); nodep;
nodep = VN_CAST(nodep->nextp(), NodeModule)) {
if (nodep->level() <= 2) tops.push_back(nodep);
mods.push_back(nodep);
}
if (tops.size() >= 2) {
AstNode* secp = tops[1]; // Complain about second one, as first often intended
if (!secp->fileline()->warnIsOff(V3ErrorCode::MULTITOP)) {
secp->v3warn(MULTITOP, "Multiple top level modules\n"
<< secp->warnMore()
<< "... Suggest see manual; fix the duplicates, or use "
"--top-module to select top."
<< V3Error::warnContextNone());
for (AstNode* alsop : tops) {
std::cout << secp->warnMore() << "... Top module " << alsop->prettyNameQ() << endl
<< alsop->warnContextSecondary();
}
}
}
timescaling(mods);
// Reorder the netlist's modules to have modules in level sorted order
stable_sort(mods.begin(), mods.end(), CmpLevel()); // Sort the vector
UINFO(9, "modSortByLevel() sorted\n"); // Comment required for gcc4.6.3 / bug666
for (AstNodeModule* nodep : mods) {
nodep->clearIter(); // Because we didn't iterate to find the node
// pointers, may have a stale m_iterp() needing cleanup
nodep->unlinkFrBack();
}
UASSERT_OBJ(!v3Global.rootp()->modulesp(), v3Global.rootp(), "Unlink didn't work");
for (AstNodeModule* nodep : mods) v3Global.rootp()->addModulep(nodep);
UINFO(9, "modSortByLevel() done\n"); // Comment required for gcc4.6.3 / bug666
V3Global::dumpCheckGlobalTree("cells", false, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}
void V3LinkLevel::timescaling(const ModVec& mods) {
// Timescale determination
AstNodeModule* modTimedp = nullptr;
VTimescale unit(VTimescale::NONE);
// Use highest level module as default unit - already sorted in proper order
for (const auto& modp : mods) {
if (!modTimedp && !modp->timeunit().isNone()) {
modTimedp = modp;
unit = modTimedp->timeunit();
break;
}
}
unit = v3Global.opt.timeComputeUnit(unit); // Apply override
if (unit.isNone()) unit = VTimescale(VTimescale::TS_DEFAULT);
v3Global.rootp()->timeunit(unit);
for (AstNodeModule* nodep : mods) {
if (!v3Global.opt.timeOverrideUnit().isNone()) nodep->timeunit(unit);
if (nodep->timeunit().isNone()) {
if (modTimedp // Got previous
&& ( // unit doesn't already include an override
v3Global.opt.timeOverrideUnit().isNone()
&& v3Global.opt.timeDefaultUnit().isNone())
&& nodep->timescaleMatters()) {
nodep->v3warn(TIMESCALEMOD,
"Timescale missing on this module as other modules have "
"it (IEEE 1800-2017 3.14.2.3)\n"
<< nodep->warnContextPrimary() << '\n'
<< modTimedp->warnOther()
<< "... Location of module with timescale\n"
<< modTimedp->warnContextSecondary());
}
nodep->timeunit(unit);
}
}
v3Global.rootp()->timescaleSpecified(modTimedp); // true if some module specifies timescale
if (v3Global.rootp()->timeprecision().isNone()) {
v3Global.rootp()->timeprecisionMerge(v3Global.rootp()->fileline(),
VTimescale(VTimescale::TS_DEFAULT));
}
}
//######################################################################
// Wrapping
void V3LinkLevel::wrapTop(AstNetlist* rootp) {
UINFO(2, __FUNCTION__ << ": " << endl);
// We do ONLY the top module
AstNodeModule* oldmodp = rootp->modulesp();
if (!oldmodp) { // Later V3LinkDot will warn
UINFO(1, "No module found to wrap\n");
return;
}
AstNodeModule* newmodp = new AstModule(oldmodp->fileline(), string("TOP"));
// Make the new module first in the list
oldmodp->unlinkFrBackWithNext();
newmodp->addNext(oldmodp);
newmodp->level(1);
newmodp->modPublic(true);
newmodp->protect(false);
newmodp->timeunit(oldmodp->timeunit());
rootp->addModulep(newmodp);
// TODO the module creation above could be done after linkcells, but
// the rest must be done after data type resolution
wrapTopCell(rootp);
// Instantiate all packages under the top wrapper
// This way all later SCOPE based optimizations can ignore packages
for (AstNodeModule* modp = rootp->modulesp(); modp;
modp = VN_CAST(modp->nextp(), NodeModule)) {
if (VN_IS(modp, Package)) {
AstCell* cellp = new AstCell(modp->fileline(), modp->fileline(),
// Could add __03a__03a="::" to prevent conflict
// with module names/"v"
modp->name(), modp->name(), nullptr, nullptr, nullptr);
cellp->modp(modp);
newmodp->addStmtp(cellp);
}
}
V3Global::dumpCheckGlobalTree("wraptop", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 6);
}
void V3LinkLevel::wrapTopCell(AstNetlist* rootp) {
AstNodeModule* newmodp = rootp->modulesp();
UASSERT_OBJ(newmodp && newmodp->isTop(), rootp, "No TOP module found to insert under");
// Find all duplicate signal names (if multitop)
using NameSet = std::unordered_set<std::string>;
NameSet ioNames;
NameSet dupNames;
// For all modules, skipping over new top
for (AstNodeModule* oldmodp = VN_CAST(rootp->modulesp()->nextp(), NodeModule);
oldmodp && oldmodp->level() <= 2; oldmodp = VN_CAST(oldmodp->nextp(), NodeModule)) {
for (AstNode* subnodep = oldmodp->stmtsp(); subnodep; subnodep = subnodep->nextp()) {
if (AstVar* oldvarp = VN_CAST(subnodep, Var)) {
if (oldvarp->isIO()) {
if (ioNames.find(oldvarp->name()) != ioNames.end()) {
// UINFO(8, "Multitop dup I/O found: " << oldvarp << endl);
dupNames.insert(oldvarp->name());
} else {
ioNames.insert(oldvarp->name());
}
}
}
}
}
// For all modules, skipping over new top
for (AstNodeModule* oldmodp = VN_CAST(rootp->modulesp()->nextp(), NodeModule);
oldmodp && oldmodp->level() <= 2; oldmodp = VN_CAST(oldmodp->nextp(), NodeModule)) {
if (VN_IS(oldmodp, Package)) continue;
// Add instance
UINFO(5, "LOOP " << oldmodp << endl);
AstCell* cellp = new AstCell(
newmodp->fileline(), newmodp->fileline(),
(!v3Global.opt.l2Name().empty() ? v3Global.opt.l2Name() : oldmodp->name()),
oldmodp->name(), nullptr, nullptr, nullptr);
cellp->modp(oldmodp);
newmodp->addStmtp(cellp);
// Add pins
for (AstNode* subnodep = oldmodp->stmtsp(); subnodep; subnodep = subnodep->nextp()) {
if (AstVar* oldvarp = VN_CAST(subnodep, Var)) {
UINFO(8, "VARWRAP " << oldvarp << endl);
if (oldvarp->isIO()) {
string name = oldvarp->name();
if (dupNames.find(name) != dupNames.end()) {
// __02E=. while __DOT__ looks nicer but will break V3LinkDot
name = oldmodp->name() + "__02E" + name;
}
AstVar* varp = oldvarp->cloneTree(false);
varp->name(name);
varp->protect(false);
newmodp->addStmtp(varp);
varp->sigPublic(true); // User needs to be able to get to it...
if (oldvarp->isIO()) {
oldvarp->primaryIO(false);
varp->primaryIO(true);
}
if (varp->direction().isRefOrConstRef()) {
varp->v3warn(E_UNSUPPORTED,
"Unsupported: ref/const ref as primary input/output: "
<< varp->prettyNameQ());
}
if (varp->isIO() && v3Global.opt.systemC()) {
varp->sc(true);
// User can see trace one level down from the wrapper
// Avoids packing & unpacking SC signals a second time
varp->trace(false);
}
AstPin* pinp = new AstPin(
oldvarp->fileline(), 0, varp->name(),
new AstVarRef(varp->fileline(), varp,
oldvarp->isWritable() ? VAccess::WRITE : VAccess::READ));
// Skip length and width comp; we know it's a direct assignment
pinp->modVarp(oldvarp);
cellp->addPinsp(pinp);
}
}
}
}
}