verilator/src/V3AssertPre.cpp

211 lines
8.0 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Collect and print statistics
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2005-2021 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
//
//*************************************************************************
// Pre steps:
// Attach clocks to each assertion
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include "V3Global.h"
#include "V3AssertPre.h"
//######################################################################
// Assert class functions
class AssertPreVisitor final : public AstNVisitor {
// Removes clocks and other pre-optimizations
// Eventually inlines calls to sequences, properties, etc.
// We're not parsing the tree, or anything more complicated.
private:
// NODE STATE/TYPES
// STATE
// Reset each module:
AstSenItem* m_seniDefaultp = nullptr; // Default sensitivity (from AstDefClock)
// Reset each assertion:
AstSenItem* m_senip = nullptr; // Last sensitivity
// Reset each always:
AstSenItem* m_seniAlwaysp = nullptr; // Last sensitivity in always
// Reset each assertion:
AstNode* m_disablep = nullptr; // Last disable
// METHODS
VL_DEBUG_FUNC; // Declare debug()
AstSenTree* newSenTree(AstNode* nodep) {
// Create sentree based on clocked or default clock
// Return nullptr for always
AstSenTree* newp = nullptr;
AstSenItem* senip = m_senip;
if (!senip) senip = m_seniDefaultp;
if (!senip) senip = m_seniAlwaysp;
if (!senip) {
nodep->v3warn(E_UNSUPPORTED, "Unsupported: Unclocked assertion");
newp = new AstSenTree(nodep->fileline(), nullptr);
} else {
newp = new AstSenTree(nodep->fileline(), senip->cloneTree(true));
}
return newp;
}
void clearAssertInfo() {
m_senip = nullptr;
m_disablep = nullptr;
}
// VISITORS
//========== Statements
virtual void visit(AstClocking* nodep) override {
UINFO(8, " CLOCKING" << nodep << endl);
// Store the new default clock, reset on new module
m_seniDefaultp = nodep->sensesp();
// Trash it, keeping children
if (nodep->bodysp()) {
nodep->replaceWith(nodep->bodysp()->unlinkFrBack());
} else {
nodep->unlinkFrBack();
}
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstAlways* nodep) override {
iterateAndNextNull(nodep->sensesp());
if (nodep->sensesp()) m_seniAlwaysp = nodep->sensesp()->sensesp();
iterateAndNextNull(nodep->bodysp());
m_seniAlwaysp = nullptr;
}
virtual void visit(AstNodeCoverOrAssert* nodep) override {
if (nodep->sentreep()) return; // Already processed
clearAssertInfo();
// Find Clocking's buried under nodep->exprsp
iterateChildren(nodep);
if (!nodep->immediate()) nodep->sentreep(newSenTree(nodep));
clearAssertInfo();
}
virtual void visit(AstFell* nodep) override {
if (nodep->sentreep()) return; // Already processed
iterateChildren(nodep);
FileLine* const fl = nodep->fileline();
AstNode* exprp = nodep->exprp()->unlinkFrBack();
if (exprp->width() > 1) exprp = new AstSel(fl, exprp, 0, 1);
AstNode* const past = new AstPast(fl, exprp, nullptr);
past->dtypeFrom(exprp);
exprp = new AstAnd(fl, past, new AstNot(fl, exprp->cloneTree(false)));
exprp->dtypeSetBit();
nodep->replaceWith(exprp);
nodep->sentreep(newSenTree(nodep));
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstPast* nodep) override {
if (nodep->sentreep()) return; // Already processed
iterateChildren(nodep);
nodep->sentreep(newSenTree(nodep));
}
virtual void visit(AstRose* nodep) override {
if (nodep->sentreep()) return; // Already processed
iterateChildren(nodep);
FileLine* const fl = nodep->fileline();
AstNode* exprp = nodep->exprp()->unlinkFrBack();
if (exprp->width() > 1) exprp = new AstSel(fl, exprp, 0, 1);
AstNode* const past = new AstPast(fl, exprp, nullptr);
past->dtypeFrom(exprp);
exprp = new AstAnd(fl, new AstNot(fl, past), exprp->cloneTree(false));
exprp->dtypeSetBit();
nodep->replaceWith(exprp);
nodep->sentreep(newSenTree(nodep));
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstStable* nodep) override {
if (nodep->sentreep()) return; // Already processed
iterateChildren(nodep);
FileLine* const fl = nodep->fileline();
AstNode* exprp = nodep->exprp()->unlinkFrBack();
AstNode* const past = new AstPast(fl, exprp, nullptr);
past->dtypeFrom(exprp);
exprp = new AstEq(fl, past, exprp->cloneTree(false));
exprp->dtypeSetBit();
nodep->replaceWith(exprp);
nodep->sentreep(newSenTree(nodep));
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstImplication* nodep) override {
if (nodep->sentreep()) return; // Already processed
FileLine* const fl = nodep->fileline();
AstNode* const rhsp = nodep->rhsp()->unlinkFrBack();
AstNode* lhsp = nodep->lhsp()->unlinkFrBack();
if (m_disablep) lhsp = new AstAnd(fl, new AstNot(fl, m_disablep), lhsp);
AstNode* const past = new AstPast(fl, lhsp, nullptr);
past->dtypeFrom(lhsp);
AstNode* const exprp = new AstOr(fl, new AstNot(fl, past), rhsp);
exprp->dtypeSetBit();
nodep->replaceWith(exprp);
nodep->sentreep(newSenTree(nodep));
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstPropClocked* nodep) override {
// No need to iterate the body, once replace will get iterated
iterateAndNextNull(nodep->sensesp());
if (m_senip)
nodep->v3warn(E_UNSUPPORTED, "Unsupported: Only one PSL clock allowed per assertion");
// Block is the new expression to evaluate
AstNode* blockp = nodep->propp()->unlinkFrBack();
if (nodep->disablep()) {
m_disablep = nodep->disablep()->cloneTree(false);
if (VN_IS(nodep->backp(), Cover)) {
blockp = new AstAnd(
nodep->disablep()->fileline(),
new AstNot(nodep->disablep()->fileline(), nodep->disablep()->unlinkFrBack()),
blockp);
} else {
blockp = new AstOr(nodep->disablep()->fileline(),
nodep->disablep()->unlinkFrBack(), blockp);
}
}
// Unlink and just keep a pointer to it, convert to sentree as needed
m_senip = nodep->sensesp();
nodep->replaceWith(blockp);
VL_DO_DANGLING(pushDeletep(nodep), nodep);
}
virtual void visit(AstNodeModule* nodep) override {
iterateChildren(nodep);
// Reset defaults
m_seniDefaultp = nullptr;
}
virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
public:
// CONSTRUCTORS
explicit AssertPreVisitor(AstNetlist* nodep) {
clearAssertInfo();
// Process
iterate(nodep);
}
virtual ~AssertPreVisitor() override = default;
};
//######################################################################
// Top Assert class
void V3AssertPre::assertPreAll(AstNetlist* nodep) {
UINFO(2, __FUNCTION__ << ": " << endl);
{ AssertPreVisitor{nodep}; } // Destruct before checking
V3Global::dumpCheckGlobalTree("assertpre", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
}