verilator/src/V3Randomize.cpp
2022-01-08 11:18:23 -05:00

282 lines
12 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Expression width calculations
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2022 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
//
//*************************************************************************
// V3Randomize's Transformations:
//
// Each randomize() method call:
// Mark class of object on which randomize() is called
// Mark all classes that inherit from previously marked classed
// Mark all classes whose instances are randomized member variables of marked classes
// Each marked class:
// define a virtual randomize() method that randomizes its random variables
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Ast.h"
#include "V3Randomize.h"
//######################################################################
// Visitor that marks classes needing a randomize() method
class RandomizeMarkVisitor final : public VNVisitor {
private:
// NODE STATE
// Cleared on Netlist
// AstClass::user1() -> bool. Set true to indicate needs randomize processing
const VNUser1InUse m_inuser1;
using DerivedSet = std::unordered_set<AstClass*>;
using BaseToDerivedMap = std::unordered_map<AstClass*, DerivedSet>;
BaseToDerivedMap m_baseToDerivedMap; // Mapping from base classes to classes that extend them
// METHODS
VL_DEBUG_FUNC;
void markMembers(AstClass* nodep) {
for (auto* classp = nodep; classp;
classp = classp->extendsp() ? classp->extendsp()->classp() : nullptr) {
for (auto* memberp = classp->stmtsp(); memberp; memberp = memberp->nextp()) {
// If member is rand and of class type, mark its class
if (VN_IS(memberp, Var) && VN_AS(memberp, Var)->isRand()) {
if (const auto* const classRefp = VN_CAST(memberp->dtypep(), ClassRefDType)) {
auto* const rclassp = classRefp->classp();
markMembers(rclassp);
markDerived(rclassp);
rclassp->user1(true);
}
}
}
}
}
void markDerived(AstClass* nodep) {
const auto it = m_baseToDerivedMap.find(nodep);
if (it != m_baseToDerivedMap.end()) {
for (auto* classp : it->second) {
classp->user1(true);
markMembers(classp);
markDerived(classp);
}
}
}
void markAllDerived() {
for (auto p : m_baseToDerivedMap) {
if (p.first->user1()) markDerived(p.first);
}
}
// VISITORS
virtual void visit(AstClass* nodep) override {
iterateChildren(nodep);
if (nodep->extendsp()) {
// Save pointer to derived class
auto* const basep = nodep->extendsp()->classp();
m_baseToDerivedMap[basep].insert(nodep);
}
}
virtual void visit(AstMethodCall* nodep) override {
iterateChildren(nodep);
if (nodep->name() != "randomize") return;
if (const AstClassRefDType* const classRefp
= VN_CAST(nodep->fromp()->dtypep(), ClassRefDType)) {
auto* const classp = classRefp->classp();
classp->user1(true);
markMembers(classp);
}
}
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit RandomizeMarkVisitor(AstNetlist* nodep) {
iterate(nodep);
markAllDerived();
}
virtual ~RandomizeMarkVisitor() override = default;
};
//######################################################################
// Visitor that defines a randomize method where needed
class RandomizeVisitor final : public VNVisitor {
private:
// NODE STATE
// Cleared on Netlist
// AstClass::user1() -> bool. Set true to indicate needs randomize processing
// AstEnumDType::user2() -> AstVar*. Pointer to table with enum values
// VNUser1InUse m_inuser1; (Allocated for use in RandomizeMarkVisitor)
const VNUser2InUse m_inuser2;
// STATE
size_t m_enumValueTabCount = 0; // Number of tables with enum values created
// METHODS
VL_DEBUG_FUNC;
AstVar* enumValueTabp(AstEnumDType* nodep) {
if (nodep->user2p()) return VN_AS(nodep->user2p(), Var);
UINFO(9, "Construct Venumvaltab " << nodep << endl);
AstNodeArrayDType* const vardtypep
= new AstUnpackArrayDType(nodep->fileline(), nodep->dtypep(),
new AstRange(nodep->fileline(), nodep->itemCount(), 0));
AstInitArray* const initp = new AstInitArray(nodep->fileline(), vardtypep, nullptr);
v3Global.rootp()->typeTablep()->addTypesp(vardtypep);
AstVar* const varp
= new AstVar(nodep->fileline(), VVarType::MODULETEMP,
"__Venumvaltab_" + cvtToStr(m_enumValueTabCount++), vardtypep);
varp->isConst(true);
varp->isStatic(true);
varp->valuep(initp);
// Add to root, as don't know module we are in, and aids later structure sharing
v3Global.rootp()->dollarUnitPkgAddp()->addStmtp(varp);
UASSERT_OBJ(nodep->itemsp(), nodep, "Enum without items");
for (AstEnumItem* itemp = nodep->itemsp(); itemp;
itemp = VN_AS(itemp->nextp(), EnumItem)) {
AstConst* const vconstp = VN_AS(itemp->valuep(), Const);
UASSERT_OBJ(vconstp, nodep, "Enum item without constified value");
initp->addValuep(vconstp->cloneTree(false));
}
nodep->user2p(varp);
return varp;
}
AstNodeStmt* newRandStmtsp(FileLine* fl, AstNodeVarRef* varrefp, int offset = 0,
AstMemberDType* memberp = nullptr) {
if (const auto* const structDtp
= VN_CAST(memberp ? memberp->subDTypep()->skipRefp() : varrefp->dtypep()->skipRefp(),
StructDType)) {
AstNodeStmt* stmtsp = nullptr;
offset += memberp ? memberp->lsb() : 0;
for (auto* smemberp = structDtp->membersp(); smemberp;
smemberp = VN_AS(smemberp->nextp(), MemberDType)) {
auto* const randp = newRandStmtsp(fl, stmtsp ? varrefp->cloneTree(false) : varrefp,
offset, smemberp);
if (stmtsp) {
stmtsp->addNext(randp);
} else {
stmtsp = randp;
}
}
return stmtsp;
} else {
AstNodeMath* valp;
if (auto* const enumDtp = VN_CAST(memberp ? memberp->subDTypep()->subDTypep()
: varrefp->dtypep()->subDTypep(),
EnumDType)) {
AstVarRef* const tabRefp
= new AstVarRef(fl, enumValueTabp(enumDtp), VAccess::READ);
tabRefp->classOrPackagep(v3Global.rootp()->dollarUnitPkgAddp());
auto* const randp = new AstRand(fl, nullptr, false);
auto* const moddivp
= new AstModDiv(fl, randp, new AstConst(fl, enumDtp->itemCount()));
randp->dtypep(varrefp->findBasicDType(VBasicDTypeKwd::UINT32));
moddivp->dtypep(enumDtp);
valp = new AstArraySel(fl, tabRefp, moddivp);
} else {
valp = new AstRand(fl, nullptr, false);
valp->dtypep(memberp ? memberp->dtypep() : varrefp->varp()->dtypep());
}
return new AstAssign(fl,
new AstSel(fl, varrefp, offset + (memberp ? memberp->lsb() : 0),
memberp ? memberp->width() : varrefp->width()),
valp);
}
}
// VISITORS
virtual void visit(AstClass* nodep) override {
iterateChildren(nodep);
if (!nodep->user1()) return; // Doesn't need randomize, or already processed
UINFO(9, "Define randomize() for " << nodep << endl);
auto* const funcp = V3Randomize::newRandomizeFunc(nodep);
auto* const fvarp = VN_AS(funcp->fvarp(), Var);
funcp->addStmtsp(new AstAssign(
nodep->fileline(), new AstVarRef(nodep->fileline(), fvarp, VAccess::WRITE),
new AstConst(nodep->fileline(), AstConst::WidthedValue(), 32, 1)));
for (auto* classp = nodep; classp;
classp = classp->extendsp() ? classp->extendsp()->classp() : nullptr) {
for (auto* memberp = classp->stmtsp(); memberp; memberp = memberp->nextp()) {
auto* const memberVarp = VN_CAST(memberp, Var);
if (!memberVarp || !memberVarp->isRand()) continue;
const auto* const dtypep = memberp->dtypep()->skipRefp();
if (VN_IS(dtypep, BasicDType) || VN_IS(dtypep, StructDType)) {
auto* const refp
= new AstVarRef(nodep->fileline(), memberVarp, VAccess::WRITE);
auto* const stmtp = newRandStmtsp(nodep->fileline(), refp);
funcp->addStmtsp(stmtp);
} else if (const auto* const classRefp = VN_CAST(dtypep, ClassRefDType)) {
auto* const refp
= new AstVarRef(nodep->fileline(), memberVarp, VAccess::WRITE);
auto* const memberFuncp = V3Randomize::newRandomizeFunc(classRefp->classp());
auto* const callp
= new AstMethodCall(nodep->fileline(), refp, "randomize", nullptr);
callp->taskp(memberFuncp);
callp->dtypeFrom(memberFuncp);
funcp->addStmtsp(new AstAssign(
nodep->fileline(), new AstVarRef(nodep->fileline(), fvarp, VAccess::WRITE),
new AstAnd(nodep->fileline(),
new AstVarRef(nodep->fileline(), fvarp, VAccess::READ),
callp)));
} else {
memberp->v3warn(E_UNSUPPORTED,
"Unsupported: random member variables with type "
<< memberp->dtypep()->prettyDTypeNameQ());
}
}
}
nodep->user1(false);
}
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit RandomizeVisitor(AstNetlist* nodep) { iterate(nodep); }
virtual ~RandomizeVisitor() override = default;
};
//######################################################################
// Randomize method class functions
void V3Randomize::randomizeNetlist(AstNetlist* nodep) {
UINFO(2, __FUNCTION__ << ": " << endl);
{
const RandomizeMarkVisitor markVisitor{nodep};
RandomizeVisitor{nodep};
}
V3Global::dumpCheckGlobalTree("randomize", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}
AstFunc* V3Randomize::newRandomizeFunc(AstClass* nodep) {
auto* funcp = VN_AS(nodep->findMember("randomize"), Func);
if (!funcp) {
auto* const dtypep
= nodep->findBitDType(32, 32, VSigning::SIGNED); // IEEE says int return of 0/1
auto* const fvarp = new AstVar(nodep->fileline(), VVarType::MEMBER, "randomize", dtypep);
fvarp->lifetime(VLifetime::AUTOMATIC);
fvarp->funcLocal(true);
fvarp->funcReturn(true);
fvarp->direction(VDirection::OUTPUT);
funcp = new AstFunc(nodep->fileline(), "randomize", nullptr, fvarp);
funcp->dtypep(dtypep);
funcp->classMethod(true);
funcp->isVirtual(nodep->isExtended());
nodep->addMembersp(funcp);
nodep->repairCache();
}
return funcp;
}