// VISITORS
virtual void visit(AstNodeVarRef* nodep, AstNUser*) {
if (nodep->varScopep() == m_elimVarScp) {
// Substitute in the new tree
// It's possible we substitute into something that will be reduced more later
// however, as we never delete the top Always/initial statement, all should be well.
m_didReplace = true;
if (nodep->lvalue()) nodep->v3fatalSrc("Can't replace lvalue assignments with const var");
AstNode* substp = m_replaceTreep->cloneTree(false);
if (nodep->castNodeVarRef()
&& substp->castNodeVarRef()
&& nodep->same(substp)) {
// Prevent a infinite loop...
substp->v3fatalSrc("Replacing node with itself; perhaps circular logic?");
}
// Which fileline() to use?
// If replacing with logic, an error/warning is likely to want to point to the logic
// IE what we're replacing with.
// However a VARREF should point to the original as it's otherwise confusing
// to throw warnings that point to a PIN rather than where the pin us used.
if (substp->castVarRef()) substp->fileline(nodep->fileline());
// Make the substp an rvalue like nodep. This facilitate the hashing in dedupe.
if (AstNodeVarRef* varrefp = substp->castNodeVarRef()) varrefp->lvalue(false);
nodep->replaceWith(substp);
nodep->deleteTree(); VL_DANGLING(nodep);
}
}
void visit(AstSel* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (!nodep->user1Inc()) {
// Guard against reading/writing past end of bit vector array
int maxmsb = 0;
bool lvalue = false;
AstNode* basefromp = AstArraySel::baseFromp(nodep);
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) {
lvalue = varrefp->lvalue();
maxmsb = (varrefp->varp()->width()-1);
} else {
// If it's a PARAMETER[bit], then basefromp may be a constant instead of a varrefp
maxmsb = basefromp->width()-1;
}
int maxlsb = maxmsb - nodep->width() + 1;
if (debug()>=9) nodep->dumpTree(cout,"sel_old: ");
V3Number maxlsbnum (nodep->fileline(), nodep->lsbp()->width(), maxlsb);
// See if the condition is constant true
AstNode* condp = new AstLte (nodep->fileline(),
nodep->lsbp()->cloneTree(false),
new AstConst(nodep->fileline(), maxlsbnum));
// Note below has null backp(); the Edit function knows how to deal with that.
condp = V3Const::constifyEdit(condp);
if (condp->isOne()) {
// We don't need to add a conditional; we know the existing expression is ok
condp->deleteTree();
}
else if (!lvalue) {
// SEL(...) -> COND(LTE(bit<=maxlsb), ARRAYSEL(...), {width{1'bx}})
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
V3Number xnum (nodep->fileline(), nodep->width());
xnum.setAllBitsX();
AstNode* newp = new AstCondBound (nodep->fileline(),
condp,
nodep,
new AstConst(nodep->fileline(), xnum));
if (debug()>=9) newp->dumpTree(cout," _new: ");
// Link in conditional
replaceHandle.relink(newp);
// Added X's, tristate them too
newp->accept(*this);
}
else { // lvalue
replaceBoundLvalue(nodep, condp);
}
}
}
virtual void visit(AstSel* nodep) {
nodep->iterateChildren(*this);
if (!nodep->user1SetOnce()) {
// Guard against reading/writing past end of bit vector array
AstNode* basefromp = AstArraySel::baseFromp(nodep);
bool lvalue = false;
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) {
lvalue = varrefp->lvalue();
}
// Find range of dtype we are selecting from
// Similar code in V3Const::warnSelect
int maxmsb = nodep->fromp()->dtypep()->width()-1;
if (debug()>=9) nodep->dumpTree(cout,"sel_old: ");
V3Number maxmsbnum (nodep->fileline(), nodep->lsbp()->width(), maxmsb);
// If (maxmsb >= selected), we're in bound
AstNode* condp = new AstGte (nodep->fileline(),
new AstConst(nodep->fileline(), maxmsbnum),
nodep->lsbp()->cloneTree(false));
// See if the condition is constant true (e.g. always in bound due to constant select)
// Note below has null backp(); the Edit function knows how to deal with that.
condp = V3Const::constifyEdit(condp);
if (condp->isOne()) {
// We don't need to add a conditional; we know the existing expression is ok
condp->deleteTree();
}
else if (!lvalue) {
// SEL(...) -> COND(LTE(bit<=maxmsb), ARRAYSEL(...), {width{1'bx}})
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
V3Number xnum (nodep->fileline(), nodep->width());
xnum.setAllBitsX();
AstNode* newp = new AstCondBound (nodep->fileline(),
condp,
nodep,
new AstConst(nodep->fileline(), xnum));
if (debug()>=9) newp->dumpTree(cout," _new: ");
// Link in conditional
replaceHandle.relink(newp);
// Added X's, tristate them too
newp->accept(*this);
}
else { // lvalue
replaceBoundLvalue(nodep, condp);
}
}
}
// PUBLIC METHODS
AstNodeVarRef* findDupe(AstNode* nodep, AstVarScope* consumerVarScopep, AstActive* activep) {
m_assignp = NULL;
m_ifCondp = NULL;
m_always = false;
m_dedupable = true;
nodep->accept(*this);
if (m_dedupable && m_assignp) {
AstNode* lhsp = m_assignp->lhsp();
// Possible todo, handle more complex lhs expressions
if (AstNodeVarRef* lhsVarRefp = lhsp->castNodeVarRef()) {
if (lhsVarRefp->varScopep() != consumerVarScopep) consumerVarScopep->v3fatalSrc("Consumer doesn't match lhs of assign");
if (AstNodeAssign* dup = m_hash.hashAndFindDupe(m_assignp,activep,m_ifCondp)) {
return (AstNodeVarRef*) dup->lhsp();
}
}
}
return NULL;
}
virtual void visit(AstNodePreSel* nodep, AstNUser*) {
if (!nodep->attrp()) {
nodep->iterateChildren(*this);
// Constification may change the fromp() to a constant, which will lose the
// variable we're extracting from (to determine MSB/LSB/endianness/etc.)
// So we replicate it in another node
// Note that V3Param knows not to replace AstVarRef's under AstAttrOf's
AstNode* basefromp = AstArraySel::baseFromp(nodep);
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) { // Maybe varxref - so need to clone
nodep->attrp(new AstAttrOf(nodep->fileline(), AstAttrType::VAR_BASE,
varrefp->cloneTree(false)));
} else if (AstMemberSel* fromp = basefromp->castMemberSel()) {
nodep->attrp(new AstAttrOf(nodep->fileline(), AstAttrType::MEMBER_BASE,
fromp->cloneTree(false)));
} else {
nodep->v3fatalSrc("Illegal bit select; no signal/member being extracted from");
}
}
}
virtual void visit(AstSenItem* nodep, AstNUser*) {
// Remove bit selects, and bark if it's not a simple variable
nodep->iterateChildren(*this);
if (nodep->isClocked()) {
// If it's not a simple variable wrap in a temporary
// This is a bit unfortunate as we haven't done width resolution
// and any width errors will look a bit odd, but it works.
AstNode* sensp = nodep->sensp();
if (sensp
&& !sensp->castNodeVarRef()
&& !sensp->castConst()) {
// Make a new temp wire
string newvarname = "__Vsenitemexpr"+cvtToStr(++m_senitemCvtNum);
AstVar* newvarp = new AstVar (sensp->fileline(), AstVarType::MODULETEMP, newvarname,
VFlagLogicPacked(), 1);
// We can't just add under the module, because we may be inside a generate, begin, etc.
// We know a SenItem should be under a SenTree/Always etc, we we'll just hunt upwards
AstNode* addwherep = nodep; // Add to this element's next
while (addwherep->castSenItem()
|| addwherep->castSenTree()) {
addwherep = addwherep->backp();
}
if (!addwherep->castAlways()) { // Assertion perhaps?
sensp->v3error("Unsupported: Non-single-bit pos/negedge clock statement under some complicated block");
addwherep = m_modp;
}
addwherep->addNext(newvarp);
sensp->replaceWith(new AstVarRef (sensp->fileline(), newvarp, false));
AstAssignW* assignp = new AstAssignW
(sensp->fileline(),
new AstVarRef(sensp->fileline(), newvarp, true),
sensp);
addwherep->addNext(assignp);
}
} else { // Old V1995 sensitivity list; we'll probably mostly ignore
bool did=1;
while (did) {
did=0;
if (AstNodeSel* selp = nodep->sensp()->castNodeSel()) {
AstNode* fromp = selp->fromp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
// NodeSel doesn't include AstSel....
if (AstSel* selp = nodep->sensp()->castSel()) {
AstNode* fromp = selp->fromp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
if (AstNodePreSel* selp = nodep->sensp()->castNodePreSel()) {
AstNode* fromp = selp->lhsp()->unlinkFrBack();
selp->replaceWith(fromp); selp->deleteTree(); selp=NULL;
did=1;
}
}
}
if (!nodep->sensp()->castNodeVarRef()
&& !nodep->sensp()->castEnumItemRef()) { // V3Const will cleanup
if (debug()) nodep->dumpTree(cout,"-tree: ");
nodep->v3error("Unsupported: Complex statement in sensitivity list");
}
}
virtual void visit(AstArraySel* nodep) {
nodep->iterateChildren(*this);
if (!nodep->user1SetOnce()) {
if (debug()==9) nodep->dumpTree(cout,"-in: ");
// Guard against reading/writing past end of arrays
AstNode* basefromp = AstArraySel::baseFromp(nodep->fromp());
bool lvalue = false;
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) {
lvalue = varrefp->lvalue();
} else if (basefromp->castConst()) {
// If it's a PARAMETER[bit], then basefromp may be a constant instead of a varrefp
} else {
nodep->v3fatalSrc("No VarRef or Const under ArraySel");
}
// Find range of dtype we are selecting from
int declElements = -1;
AstNodeDType* dtypep = nodep->fromp()->dtypep()->skipRefp();
if (!dtypep) nodep->v3fatalSrc("Select of non-selectable type");
if (AstNodeArrayDType* adtypep = dtypep->castNodeArrayDType()) {
declElements = adtypep->elementsConst();
} else {
nodep->v3error("Select from non-array "<<dtypep->prettyTypeName());
}
if (debug()>=9) nodep->dumpTree(cout,"arraysel_old: ");
V3Number widthnum (nodep->fileline(), nodep->bitp()->width(), declElements-1);
// See if the condition is constant true
AstNode* condp = new AstGte (nodep->fileline(),
new AstConst(nodep->fileline(), widthnum),
nodep->bitp()->cloneTree(false));
// Note below has null backp(); the Edit function knows how to deal with that.
condp = V3Const::constifyEdit(condp);
if (condp->isOne()) {
// We don't need to add a conditional; we know the existing expression is ok
condp->deleteTree();
}
else if (!lvalue
&& !nodep->backp()->castArraySel()) { // Too complicated and slow if mid-multidimension
// ARRAYSEL(...) -> COND(LT(bit<maxbit), ARRAYSEL(...), {width{1'bx}})
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
V3Number xnum (nodep->fileline(), nodep->width());
if (nodep->isString()) {
xnum = V3Number(V3Number::String(), nodep->fileline(), "");
} else {
xnum.setAllBitsX();
}
AstNode* newp = new AstCondBound (nodep->fileline(),
condp,
nodep,
new AstConst(nodep->fileline(), xnum));
if (debug()>=9) newp->dumpTree(cout," _new: ");
// Link in conditional, can blow away temp xor
replaceHandle.relink(newp);
// Added X's, tristate them too
newp->accept(*this);
}
else if (!lvalue) { // Mid-multidimension read, just use zero
// ARRAYSEL(...) -> ARRAYSEL(COND(LT(bit<maxbit), bit, 0))
AstNRelinker replaceHandle;
AstNode* bitp = nodep->bitp()->unlinkFrBack(&replaceHandle);
V3Number zeronum (nodep->fileline(), bitp->width(), 0);
AstNode* newp = new AstCondBound (bitp->fileline(),
condp,
bitp,
new AstConst(bitp->fileline(), zeronum));
// Added X's, tristate them too
if (debug()>=9) newp->dumpTree(cout," _new: ");
replaceHandle.relink(newp);
newp->accept(*this);
}
else { // lvalue
replaceBoundLvalue(nodep, condp);
}
}
}
virtual void visit(AstArraySel* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (!nodep->user1Inc()) {
if (debug()==9) nodep->dumpTree(cout,"-in: ");
// Guard against reading/writing past end of arrays
AstNode* basefromp = AstArraySel::baseFromp(nodep->fromp());
int dimension = AstArraySel::dimension(nodep->fromp());
int maxmsb = 0;
bool lvalue = false;
if (AstNodeVarRef* varrefp = basefromp->castNodeVarRef()) {
AstArrayDType* adtypep = varrefp->varp()->dtypep()->dtypeDimensionp(dimension)->castArrayDType();
if (!adtypep) nodep->v3fatalSrc("ArraySel to type without array at same depth");
lvalue = varrefp->lvalue();
maxmsb = adtypep->elementsConst()-1;
} else if (AstConst* lhconstp = basefromp->castConst()) {
// If it's a PARAMETER[bit], then basefromp may be a constant instead of a varrefp
maxmsb = lhconstp->width();
} else {
nodep->v3fatalSrc("No VarRef or Const under ArraySel\n");
}
if (debug()>=9) nodep->dumpTree(cout,"arraysel_old: ");
V3Number widthnum (nodep->fileline(), nodep->bitp()->width(), maxmsb);
// See if the condition is constant true
AstNode* condp = new AstLte (nodep->fileline(),
nodep->bitp()->cloneTree(false),
new AstConst(nodep->fileline(), widthnum));
// Note below has null backp(); the Edit function knows how to deal with that.
condp = V3Const::constifyEdit(condp);
if (condp->isOne()) {
// We don't need to add a conditional; we know the existing expression is ok
condp->deleteTree();
}
else if (!lvalue
&& !nodep->backp()->castArraySel()) { // Too complicated and slow if mid-multidimension
// ARRAYSEL(...) -> COND(LT(bit<maxbit), ARRAYSEL(...), {width{1'bx}})
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
V3Number xnum (nodep->fileline(), nodep->width());
xnum.setAllBitsX();
AstNode* newp = new AstCondBound (nodep->fileline(),
condp,
nodep,
new AstConst(nodep->fileline(), xnum));
if (debug()>=9) newp->dumpTree(cout," _new: ");
// Link in conditional, can blow away temp xor
replaceHandle.relink(newp);
// Added X's, tristate them too
newp->accept(*this);
}
else if (!lvalue) { // Mid-multidimension read, just use zero
// ARRAYSEL(...) -> ARRAYSEL(COND(LT(bit<maxbit), bit, 0))
AstNRelinker replaceHandle;
AstNode* bitp = nodep->bitp()->unlinkFrBack(&replaceHandle);
V3Number zeronum (nodep->fileline(), bitp->width(), 0);
AstNode* newp = new AstCondBound (bitp->fileline(),
condp,
bitp,
new AstConst(bitp->fileline(), zeronum));
// Added X's, tristate them too
if (debug()>=9) newp->dumpTree(cout," _new: ");
replaceHandle.relink(newp);
newp->accept(*this);
}
else { // lvalue
replaceBoundLvalue(nodep, condp);
}
}
}
