void insertCast(AstNode* nodep, int needsize) { // We'll insert ABOVE passed node
UINFO(4," NeedCast "<<nodep<<endl);
AstNRelinker relinkHandle;
nodep->unlinkFrBack(&relinkHandle);
//
AstCCast* castp = new AstCCast (nodep->fileline(), nodep, needsize, nodep->widthMin());
relinkHandle.relink(castp);
//if (debug()>8) castp->dumpTree(cout,"-castins: ");
//
insureLower32Cast(castp);
nodep->user1(1); // Now must be of known size
}
AstJumpLabel* findAddLabel(AstNode* nodep, bool endOfIter) {
// Put label under given node, and if WHILE optionally at end of iteration
UINFO(4,"Create label for "<<nodep<<endl);
if (nodep->castJumpLabel()) return nodep->castJumpLabel(); // Done
AstNode* underp = NULL;
bool under_and_next = true;
if (nodep->castBegin()) underp = nodep->castBegin()->stmtsp();
else if (nodep->castNodeFTask()) underp = nodep->castNodeFTask()->stmtsp();
else if (nodep->castWhile()) {
if (endOfIter) {
// Note we jump to end of bodysp; a FOR loop has its increment under incsp() which we don't skip
underp = nodep->castWhile()->bodysp();
} else {
underp = nodep; under_and_next=false; // IE we skip the entire while
}
}
else {
nodep->v3fatalSrc("Unknown jump point for break/disable/continue");
return NULL;
}
// Skip over variables as we'll just move them in a momement
// Also this would otherwise prevent us from using a label twice
// see t_func_return test.
while (underp && underp->castVar()) underp = underp->nextp();
if (underp) UINFO(5," Underpoint is "<<underp<<endl);
if (!underp) {
nodep->v3fatalSrc("Break/disable/continue not under expected statement");
return NULL;
} else if (underp->castJumpLabel()) {
return underp->castJumpLabel();
} else { // Move underp stuff to be under a new label
AstJumpLabel* labelp = new AstJumpLabel(nodep->fileline(), NULL);
AstNRelinker repHandle;
if (under_and_next) underp->unlinkFrBackWithNext(&repHandle);
else underp->unlinkFrBack(&repHandle);
repHandle.relink(labelp);
labelp->addStmtsp(underp);
// Keep any AstVars under the function not under the new JumpLabel
for (AstNode* nextp, *varp=underp; varp; varp = nextp) {
nextp = varp->nextp();
if (varp->castVar()) {
labelp->addPrev(varp->unlinkFrBack());
}
}
return labelp;
}
}
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);
}
}
}
void visitShift (AstNodeBiop* nodep) {
// Shifts of > 32/64 bits in C++ will wrap-around and generate non-0s
if (!nodep->user2SetOnce()) {
UINFO(4," ShiftFix "<<nodep<<endl);
AstConst* shiftp = nodep->rhsp()->castConst();
if (shiftp && shiftp->num().mostSetBitP1() > 32) {
shiftp->v3error("Unsupported: Shifting of by over 32-bit number isn't supported."
<<" (This isn't a shift of 32 bits, but a shift of 2^32, or 4 billion!)\n");
}
if (nodep->widthMin()<=64 // Else we'll use large operators which work right
// C operator's width must be < maximum shift which is based on Verilog width
&& nodep->width() < (1LL<<nodep->rhsp()->widthMin())) {
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
AstNode* constzerop;
int m1value = nodep->widthMin()-1; // Constant of width-1; not changing dtype width
if (nodep->signedFlavor()) {
// Then over shifting gives the sign bit, not all zeros
// Note *NOT* clean output -- just like normal shift!
// Create equivalent of VL_SIGNONES_(node_width)
constzerop = new AstNegate (nodep->fileline(),
new AstShiftR(nodep->fileline(),
nodep->lhsp()->cloneTree(false),
new AstConst(nodep->fileline(),
m1value),
nodep->width()));
} else {
V3Number zeronum (nodep->fileline(), nodep->width(), 0);
constzerop = new AstConst(nodep->fileline(), zeronum);
}
constzerop->dtypeFrom (nodep); // unsigned
V3Number widthnum (nodep->fileline(), nodep->rhsp()->widthMin(), m1value);
AstNode* constwidthp = new AstConst(nodep->fileline(), widthnum);
constwidthp->dtypeFrom (nodep->rhsp()); // unsigned
AstCond* newp =
new AstCond (nodep->fileline(),
new AstGte (nodep->fileline(),
constwidthp,
nodep->rhsp()->cloneTree(false)),
nodep,
constzerop);
replaceHandle.relink(newp);
}
}
nodep->iterateChildren(*this); checkNode(nodep);
}
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);
}
}
}
void insertBeforeStmt(AstNode* newp) {
// Insert newp before m_stmtp
if (m_inWhilep) {
// Statements that are needed for the 'condition' in a while actually have to
// be put before & after the loop, since we can't do any statements in a while's (cond).
m_inWhilep->addPrecondsp(newp);
} else if (m_inTracep) {
m_inTracep->addPrecondsp(newp);
} else if (m_stmtp) {
AstNRelinker linker;
m_stmtp->unlinkFrBack(&linker);
newp->addNext(m_stmtp);
linker.relink(newp);
} else {
newp->v3fatalSrc("No statement insertion point.");
}
}
AstCFunc* createDeepFunc(AstNode* nodep) {
AstNRelinker relinkHandle;
nodep->unlinkFrBack(&relinkHandle);
// Create function
string name = m_funcp->name()+"__deep"+cvtToStr(++m_deepNum);
AstCFunc* funcp = new AstCFunc(nodep->fileline(), name, NULL);
funcp->argTypes(EmitCBaseVisitor::symClassVar());
funcp->symProlog(true);
funcp->slow(m_funcp->slow());
funcp->addStmtsp(nodep);
m_modp->addStmtp(funcp);
// Call it at the point where the body was removed from
AstCCall* callp = new AstCCall(nodep->fileline(), funcp);
callp->argTypes("vlSymsp");
UINFO(6," New "<<callp<<endl);
//
relinkHandle.relink(callp);
return funcp;
}
void createDeepTemp(AstNode* nodep, bool noSubst) {
if (debug()>8) nodep->dumpTree(cout,"deepin:");
AstNRelinker linker;
nodep->unlinkFrBack(&linker);
AstVar* varp = getBlockTemp(nodep);
if (noSubst) varp->noSubst(true); // Do not remove varrefs to this in V3Const
// Replace node tree with reference to var
AstVarRef* newp = new AstVarRef (nodep->fileline(), varp, false);
linker.relink(newp);
// Put assignment before the referencing statement
AstAssign* assp = new AstAssign (nodep->fileline(),
new AstVarRef(nodep->fileline(), varp, true),
nodep);
insertBeforeStmt(assp);
if (debug()>8) assp->dumpTree(cout,"deepou:");
nodep->user1(true); // Don't add another assignment
}
void reorderBlock(AstNode* nodep) {
// Reorder statements in the completed graph
// Map the rank numbers into nodes they associate with
typedef std::multimap<uint32_t,AstNode*> RankNodeMap;
RankNodeMap rankMap;
int currOrder = 0; // Existing sequence number of assignment
for (AstNode* nextp=nodep; nextp; nextp=nextp->nextp()) {
SplitLogicVertex* vvertexp = (SplitLogicVertex*)nextp->user3p();
rankMap.insert(make_pair(vvertexp->rank(), nextp));
nextp->user4(++currOrder); // Record current ordering
}
// Is the current ordering OK?
bool leaveAlone=true;
int newOrder = 0; // New sequence number of assignment
for (RankNodeMap::const_iterator it = rankMap.begin();
it != rankMap.end(); ++it) {
AstNode* nextp = it->second;
if (++newOrder != nextp->user4()) leaveAlone=false;
}
if (leaveAlone) {
UINFO(6," No changes\n");
} else {
AstNRelinker replaceHandle; // Where to add the list
AstNode* newListp = NULL;
for (RankNodeMap::const_iterator it = rankMap.begin(); it != rankMap.end(); ++it) {
AstNode* nextp = it->second;
UINFO(6, " New order: "<<nextp<<endl);
if (nextp == nodep) nodep->unlinkFrBack(&replaceHandle);
else nextp->unlinkFrBack();
if (newListp) newListp = newListp->addNext(nextp);
else newListp = nextp;
}
replaceHandle.relink(newListp);
} // leaveAlone
}
void replaceBoundLvalue(AstNode* nodep, AstNode* condp) {
// Spec says a out-of-range LHS SEL results in a NOP.
// This is a PITA. We could:
// 1. IF(...) around an ASSIGN,
// but that would break a "foo[TOO_BIG]=$fopen(...)".
// 2. Hack to extend the size of the output structure
// by one bit, and write to that temporary, but never read it.
// That makes there be two widths() and is likely a bug farm.
// 3. Make a special SEL to choose between the real lvalue
// and a temporary NOP register.
// 4. Assign to a temp, then IF that assignment.
// This is suspected to be nicest to later optimizations.
// 4 seems best but breaks later optimizations. 3 was tried,
// but makes a mess in the emitter as lvalue switching is needed. So 4.
// SEL(...) -> temp
// if (COND(LTE(bit<=maxlsb))) ASSIGN(SEL(...)),temp)
if (m_assignwp) {
// Wire assigns must become always statements to deal with insertion
// of multiple statements. Perhaps someday make all wassigns into always's?
UINFO(5," IM_WireRep "<<m_assignwp<<endl);
m_assignwp->convertToAlways(); pushDeletep(m_assignwp); m_assignwp=NULL;
}
bool needDly = (m_assigndlyp != NULL);
if (m_assigndlyp) {
// Delayed assignments become normal assignments,
// then the temp created becomes the delayed assignment
AstNode* newp = new AstAssign(m_assigndlyp->fileline(),
m_assigndlyp->lhsp()->unlinkFrBackWithNext(),
m_assigndlyp->rhsp()->unlinkFrBackWithNext());
m_assigndlyp->replaceWith(newp); pushDeletep(m_assigndlyp); m_assigndlyp=NULL;
}
AstNode* prep = nodep;
// Scan back to put the condlvalue above all selects (IE top of the lvalue)
while (prep->backp()->castNodeSel()
|| prep->backp()->castSel()) {
prep=prep->backp();
}
FileLine* fl = nodep->fileline();
VL_DANGLING(nodep); // Zap it so we don't use it by mistake - use prep
// Already exists; rather than IF(a,... IF(b... optimize to IF(a&&b,
// Saves us teaching V3Const how to optimize, and it won't be needed again.
if (AstIf* ifp = prep->user2p()->castIf()) {
if (needDly) prep->v3fatalSrc("Should have already converted to non-delay");
AstNRelinker replaceHandle;
AstNode* earliercondp = ifp->condp()->unlinkFrBack(&replaceHandle);
AstNode* newp = new AstLogAnd (condp->fileline(),
condp,
earliercondp);
UINFO(4, "Edit BOUNDLVALUE "<<newp<<endl);
replaceHandle.relink(newp);
}
else {
string name = ((string)"__Vlvbound"+cvtToStr(m_modp->varNumGetInc()));
AstVar* varp = new AstVar(fl, AstVarType::MODULETEMP, name,
prep->dtypep());
m_modp->addStmtp(varp);
AstNode* abovep = prep->backp(); // Grab above point before lose it w/ next replace
prep->replaceWith(new AstVarRef(fl, varp, true));
AstNode* newp = new AstIf(fl, condp,
(needDly
? static_cast<AstNode*>
(new AstAssignDly(fl, prep,
new AstVarRef(fl, varp, false)))
: static_cast<AstNode*>
(new AstAssign (fl, prep,
new AstVarRef(fl, varp, false)))),
NULL);
if (debug()>=9) newp->dumpTree(cout," _new: ");
abovep->addNextStmt(newp,abovep);
prep->user2p(newp); // Save so we may LogAnd it next time
}
}
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(AstConst* nodep) {
if (m_constXCvt
&& nodep->num().isFourState()) {
UINFO(4," CONST4 "<<nodep<<endl);
if (debug()>=9) nodep->dumpTree(cout," Const_old: ");
// CONST(num) -> VARREF(newvarp)
// -> VAR(newvarp)
// -> INITIAL(VARREF(newvarp, OR(num_No_Xs,AND(random,num_1s_Where_X))
V3Number numb1 (nodep->fileline(), nodep->width());
numb1.opBitsOne(nodep->num());
V3Number numbx (nodep->fileline(), nodep->width());
numbx.opBitsXZ(nodep->num());
if (v3Global.opt.xAssign()!="unique") {
// All X bits just become 0; fastest simulation, but not nice
V3Number numnew (nodep->fileline(), numb1.width());
if (v3Global.opt.xAssign()=="1") {
numnew.opOr(numb1, numbx);
} else {
numnew.opAssign(numb1);
}
AstConst* newp = new AstConst(nodep->fileline(), numnew);
nodep->replaceWith(newp);
nodep->deleteTree(); VL_DANGLING(nodep);
UINFO(4," -> "<<newp<<endl);
} else {
// Make a Vxrand variable
// We use the special XTEMP type so it doesn't break pure functions
if (!m_modp) nodep->v3fatalSrc("X number not under module");
string newvarname = ((string)"__Vxrand"
+cvtToStr(m_modp->varNumGetInc()));
AstVar* newvarp
= new AstVar (nodep->fileline(), AstVarType::XTEMP, newvarname,
VFlagLogicPacked(), nodep->width());
++m_statUnkVars;
AstNRelinker replaceHandle;
nodep->unlinkFrBack(&replaceHandle);
AstNodeVarRef* newref1p = new AstVarRef(nodep->fileline(), newvarp, false);
replaceHandle.relink(newref1p); // Replace const with varref
AstInitial* newinitp
= new AstInitial(
nodep->fileline(),
new AstAssign(
nodep->fileline(),
new AstVarRef(nodep->fileline(), newvarp, true),
new AstOr(nodep->fileline(),
new AstConst(nodep->fileline(),numb1),
new AstAnd(nodep->fileline(),
new AstConst(nodep->fileline(),numbx),
new AstRand(nodep->fileline(),
nodep->dtypep(), true)))));
// Add inits in front of other statement.
// In the future, we should stuff the initp into the module's constructor.
AstNode* afterp = m_modp->stmtsp()->unlinkFrBackWithNext();
m_modp->addStmtp(newvarp);
m_modp->addStmtp(newinitp);
m_modp->addStmtp(afterp);
if (debug()>=9) newref1p->dumpTree(cout," _new: ");
if (debug()>=9) newvarp->dumpTree(cout," _new: ");
if (debug()>=9) newinitp->dumpTree(cout," _new: ");
nodep->deleteTree(); VL_DANGLING(nodep);
}
}
}
void reorderBlock(AstNode* nodep) {
// Reorder statements in the completed graph
AstAlways* splitAlwaysp = nodep->backp()->castAlways();
// Map the rank numbers into nodes they associate with
typedef multimap<uint32_t,AstNode*> RankNodeMap;
typedef map<uint32_t,RankNodeMap> ColorRankMap;
ColorRankMap colorRankMap;
uint32_t firstColor = 0; bool multiColors = false;
int currOrder = 0; // Existing sequence number of assignment
for (AstNode* nextp=nodep; nextp; nextp=nextp->nextp()) {
SplitLogicVertex* vvertexp = (SplitLogicVertex*)nextp->user3p();
if (!splitAlwaysp) vvertexp->splitColor(1); // All blocks remain as-is
RankNodeMap& rankMap = colorRankMap[vvertexp->splitColor()];
rankMap.insert(make_pair(vvertexp->rank(), nextp));
if (firstColor && firstColor != vvertexp->splitColor()) multiColors = true;
firstColor = vvertexp->splitColor();
nextp->user4(++currOrder); // Record current ordering
}
// If there was only one color, we don't need multiple always blocks
if (!multiColors) splitAlwaysp = NULL;
// Is the current ordering OK?
bool leaveAlone=true;
if (splitAlwaysp) leaveAlone=false;
int newOrder = 0; // New sequence number of assignment
for (ColorRankMap::iterator colorIt = colorRankMap.begin(); colorIt != colorRankMap.end(); ++colorIt) {
RankNodeMap& rankMap = colorIt->second;
for (RankNodeMap::iterator it = rankMap.begin(); it != rankMap.end(); ++it) {
AstNode* nextp = it->second;
if (++newOrder != nextp->user4()) leaveAlone=false;
}
}
if (leaveAlone) {
UINFO(6," No changes\n");
} else {
AstNRelinker replaceHandle; // Where to add the list
AstNode* addAfterp = splitAlwaysp;
for (ColorRankMap::iterator colorIt = colorRankMap.begin(); colorIt != colorRankMap.end(); ++colorIt) {
uint32_t color = colorIt->first;
RankNodeMap& rankMap = colorIt->second;
AstNode* newListp = NULL;
for (RankNodeMap::iterator it = rankMap.begin(); it != rankMap.end(); ++it) {
AstNode* nextp = it->second;
UINFO(6, " Color="<<color<<" New order: "<<nextp<<endl);
if (nextp == nodep && !splitAlwaysp) nodep->unlinkFrBack(&replaceHandle);
else nextp->unlinkFrBack();
newListp = newListp->addNext(nextp);
}
if (splitAlwaysp) {
++m_statSplits;
AstAlways* alwaysp = new AstAlways(newListp->fileline(), VAlwaysKwd::ALWAYS, NULL, NULL);
addAfterp->addNextHere(alwaysp); addAfterp=alwaysp;
alwaysp->addStmtp(newListp);
} else {
// Just reordering
replaceHandle.relink(newListp);
}
}
if (splitAlwaysp) {
pushDeletep(splitAlwaysp->unlinkFrBack());
}
} // leaveAlone
}
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);
}
}
}