verilator/src/V3Clean.cpp
2011-01-01 18:21:19 -05:00

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//*************************************************************************
// DESCRIPTION: Verilator: Add temporaries, such as for clean nodes
//
// Code available from: http://www.veripool.org/verilator
//
// AUTHORS: Wilson Snyder with Paul Wasson, Duane Gabli
//
//*************************************************************************
//
// Copyright 2003-2011 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.
//
// Verilator is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
//*************************************************************************
// V3Clean's Transformations:
//
// Each module:
// For each math operator, if it requires a clean operand,
// and the operand is dirty, insert a CLEAN node.
// Resize operands to C++ 32/64/wide types.
// Copy all width() values to minWidth() so RANGE, etc can still see orig widths
//
//*************************************************************************
#include "config_build.h"
#include "verilatedos.h"
#include <cstdio>
#include <cstdarg>
#include <unistd.h>
#include <algorithm>
#include "V3Global.h"
#include "V3Clean.h"
#include "V3Ast.h"
//######################################################################
// Clean state, as a visitor of each AstNode
class CleanVisitor : public AstNVisitor {
private:
// NODE STATE
// Entire netlist:
// AstNode::user() -> CleanState. For this node, 0==UNKNOWN
// AstNode::user2() -> bool. True indicates minWidth has been propagated
AstUser1InUse m_inuser1;
AstUser2InUse m_inuser2;
// TYPES
enum CleanState { CS_UNKNOWN, CS_CLEAN, CS_DIRTY };
// STATE
AstNodeModule* m_modp;
// METHODS
static int debug() {
static int level = -1;
if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel(__FILE__);
return level;
}
// Width resetting
int cppWidth(AstNode* nodep) {
if (nodep->width()<=VL_WORDSIZE) return VL_WORDSIZE;
else if (nodep->width()<=VL_QUADSIZE) return VL_QUADSIZE;
else return nodep->widthWords()*VL_WORDSIZE;
}
void setCppWidth (AstNode* nodep, int width, int widthMin) {
nodep->user2(true); // Don't resize it again
nodep->width(width, widthMin);
}
void computeCppWidth (AstNode* nodep) {
if (!nodep->user2()) {
if (nodep->castVar() || nodep->castNodeDType()) { // Don't want to change variable widths!
setCppWidth(nodep, nodep->width(), nodep->width()); // set widthMin anyways so can see it later
} else {
setCppWidth(nodep, cppWidth(nodep), nodep->widthMin());
}
}
}
// Store the clean state in the userp on each node
void setCleanState(AstNode* nodep, CleanState clean) {
nodep->user1(clean);
}
CleanState getCleanState(AstNode* nodep) {
return ((CleanState)nodep->user1());
}
bool isClean(AstNode* nodep) {
CleanState clstate = getCleanState(nodep);
if (clstate==CS_CLEAN) return true;
if (clstate==CS_DIRTY) return false;
nodep->v3fatalSrc("Unknown clean state on node: "+nodep->prettyTypeName());
return false;
}
void setClean(AstNode* nodep, bool isClean) {
computeCppWidth (nodep); // Just to be sure it's in widthMin
bool wholeUint = ((nodep->widthMin() % VL_WORDSIZE) == 0); //32,64,...
setCleanState(nodep, ((isClean||wholeUint) ? CS_CLEAN:CS_DIRTY));
}
// Operate on nodes
void insertClean(AstNode* nodep) { // We'll insert ABOVE passed node
UINFO(4," NeedClean "<<nodep<<endl);
AstNRelinker relinkHandle;
nodep->unlinkFrBack(&relinkHandle);
//
computeCppWidth(nodep);
V3Number mask (nodep->fileline(), cppWidth(nodep));
mask.setMask(nodep->widthMin());
AstNode* cleanp = new AstAnd (nodep->fileline(),
new AstConst (nodep->fileline(), mask),
nodep);
setCppWidth (cleanp, cppWidth(nodep), nodep->widthMin());
relinkHandle.relink(cleanp);
}
void insureClean(AstNode* nodep) {
computeCppWidth(nodep);
if (!isClean(nodep)) insertClean(nodep);
}
void insureCleanAndNext(AstNode* nodep) {
// Editing list, careful looping!
for (AstNode* exprp = nodep; exprp; ) {
AstNode* nextp = exprp->nextp();
insureClean(exprp);
exprp = nextp;
}
}
// Base type handling methods
void operandBiop(AstNodeBiop* nodep) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
if (nodep->cleanLhs()) {
insureClean(nodep->lhsp());
}
if (nodep->cleanRhs()) {
insureClean(nodep->rhsp());
}
//no setClean.. must do it in each user routine.
}
void operandTriop(AstNodeTriop* nodep) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
if (nodep->cleanLhs()) {
insureClean(nodep->lhsp());
}
if (nodep->cleanRhs()) {
insureClean(nodep->rhsp());
}
if (nodep->cleanThs()) {
insureClean(nodep->thsp());
}
//no setClean.. must do it in each user routine.
}
// VISITORS
virtual void visit(AstNodeModule* nodep, AstNUser*) {
m_modp = nodep;
nodep->iterateChildren(*this);
m_modp = NULL;
}
virtual void visit(AstNodeUniop* nodep, AstNUser*) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
if (nodep->cleanLhs()) {
insureClean(nodep->lhsp());
}
setClean (nodep, nodep->cleanOut());
}
virtual void visit(AstNodeBiop* nodep, AstNUser*) {
operandBiop(nodep);
setClean (nodep, nodep->cleanOut());
}
virtual void visit(AstAnd* nodep, AstNUser*) {
operandBiop(nodep);
setClean (nodep, isClean(nodep->lhsp()) || isClean(nodep->rhsp()));
}
virtual void visit(AstXor* nodep, AstNUser*) {
operandBiop(nodep);
setClean (nodep, isClean(nodep->lhsp()) && isClean(nodep->rhsp()));
}
virtual void visit(AstOr* nodep, AstNUser*) {
operandBiop(nodep);
setClean (nodep, isClean(nodep->lhsp()) && isClean(nodep->rhsp()));
}
virtual void visit(AstNodeMath* nodep, AstNUser*) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
setClean (nodep, nodep->cleanOut());
}
virtual void visit(AstNodeAssign* nodep, AstNUser*) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
if (nodep->cleanRhs()) {
insureClean(nodep->rhsp());
}
}
virtual void visit(AstText* nodep, AstNUser*) {
setClean (nodep, true);
}
virtual void visit(AstScopeName* nodep, AstNUser*) {
setClean (nodep, true);
}
virtual void visit(AstSel* nodep, AstNUser*) {
operandTriop(nodep);
setClean (nodep, nodep->cleanOut());
}
virtual void visit(AstUCFunc* nodep, AstNUser*) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
setClean (nodep, false);
// We always clean, as we don't trust those pesky users.
if (!nodep->backp()->castAnd()) {
insertClean(nodep);
}
insureCleanAndNext (nodep->bodysp());
}
virtual void visit(AstTraceInc* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureCleanAndNext (nodep->valuep());
}
// Control flow operators
virtual void visit(AstNodeCond* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureClean(nodep->condp());
setClean(nodep, isClean(nodep->expr1p()) && isClean(nodep->expr2p()));
}
virtual void visit(AstWhile* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureClean(nodep->condp());
}
virtual void visit(AstNodeIf* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureClean(nodep->condp());
}
virtual void visit(AstSFormatF* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureCleanAndNext (nodep->exprsp());
setClean(nodep, true); // generates a string, so not relevant
}
virtual void visit(AstUCStmt* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureCleanAndNext (nodep->bodysp());
}
virtual void visit(AstCCall* nodep, AstNUser*) {
nodep->iterateChildren(*this);
insureCleanAndNext (nodep->argsp());
}
//--------------------
// Default: Just iterate
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
computeCppWidth(nodep);
}
public:
// CONSTUCTORS
CleanVisitor(AstNetlist* nodep) {
nodep->accept(*this);
}
virtual ~CleanVisitor() {}
};
//######################################################################
// Clean class functions
void V3Clean::cleanAll(AstNetlist* nodep) {
UINFO(2,__FUNCTION__<<": "<<endl);
CleanVisitor visitor (nodep);
}