virtual void visit(AstIf* nodep, AstNUser*) {
if (nodep->user1SetOnce()) return;
if (nodep->uniquePragma() || nodep->unique0Pragma()) {
AstNodeIf* ifp = nodep;
AstNode* propp = NULL;
bool hasDefaultElse = false;
do {
// If this statement ends with 'else if', then nextIf will point to the
// nextIf statement. Otherwise it will be null.
AstNodeIf* nextifp = dynamic_cast<AstNodeIf*>(ifp->elsesp());
ifp->condp()->iterateAndNext(*this);
// Recurse into the true case.
ifp->ifsp()->iterateAndNext(*this);
// If the last else is not an else if, recurse into that too.
if (ifp->elsesp() && !nextifp) {
ifp->elsesp()->iterateAndNext(*this);
}
// Build a bitmask of the true predicates
AstNode* predp = ifp->condp()->cloneTree(false);
if (propp) {
propp = new AstConcat(nodep->fileline(), predp, propp);
} else {
propp = predp;
}
// Record if this ends with an 'else' that does not have an if
if (ifp->elsesp() && !nextifp) {
hasDefaultElse = true;
}
ifp = nextifp;
} while (ifp);
AstNode *newifp = nodep->cloneTree(false);
bool allow_none = nodep->unique0Pragma();
// Note: if this ends with an 'else', then we don't need to validate that one of the
// predicates evaluates to true.
AstNode* ohot = ((allow_none || hasDefaultElse)
? (new AstOneHot0(nodep->fileline(), propp))->castNode()
: (new AstOneHot (nodep->fileline(), propp))->castNode());
AstIf* checkifp = new AstIf (nodep->fileline(),
new AstLogNot (nodep->fileline(), ohot),
newFireAssert(nodep, "'unique if' statement violated"),
newifp);
checkifp->branchPred(AstBranchPred::BP_UNLIKELY);
nodep->replaceWith(checkifp);
pushDeletep(nodep);
} else {
nodep->iterateChildren(*this);
}
}
void PrintVisitor::visit(const AstIf &ref)
{
cout << "AstIf<Condition="; ref.GetCondition()->accept(*this);
cout << "; Consequent="; ref.GetConsequent()->accept(*this);
if (ref.HasElse())
{
cout << "; Alternative="; ref.GetAlternative()->accept(*this);
}
cout << ">\n";
}
AstNode* replaceCaseFastRecurse(AstNode* cexprp, int msb, uint32_t upperValue) {
if (msb<0) {
// There's no space for a IF. We know upperValue is thus down to a specific
// exact value, so just return the tree value
// Note can't clone here, as we're going to check for equivelence above
return m_valueItem[upperValue];
}
else {
// Make left and right subtrees
// cexpr[msb:lsb] == 1
AstNode* tree0p = replaceCaseFastRecurse(cexprp, msb-1, upperValue | 0);
AstNode* tree1p = replaceCaseFastRecurse(cexprp, msb-1, upperValue | (1UL<<msb));
if (tree0p == tree1p) {
// Same logic on both sides, so we can just return one of 'em
return tree0p;
}
// We could have a "checkerboard" with A B A B, we can use the same IF on both edges
bool same = true;
for (uint32_t a=upperValue,
b=(upperValue|(1UL<<msb));
a < (upperValue|(1UL<<msb));
a++, b++) {
if (m_valueItem[a] != m_valueItem[b]) { same=false; break; }
}
if (same) {
tree1p->deleteTree(); tree1p=NULL;
return tree0p;
}
// Must have differing logic, so make a selection
// Case expressions can't be linked twice, so clone them
if (tree0p && !tree0p->user3()) tree0p = tree0p->cloneTree(true);
if (tree1p && !tree1p->user3()) tree1p = tree1p->cloneTree(true);
// Alternate scheme if we ever do multiple bits at a time:
//V3Number nummask (cexprp->fileline(), cexprp->width(), (1UL<<msb));
//AstNode* and1p = new AstAnd(cexprp->fileline(), cexprp->cloneTree(false),
// new AstConst(cexprp->fileline(), nummask));
AstNode* and1p = new AstSel(cexprp->fileline(), cexprp->cloneTree(false),
msb, 1);
AstNode* eqp = new AstNeq(cexprp->fileline(),
new AstConst(cexprp->fileline(), 0),
and1p);
AstIf* ifp = new AstIf(cexprp->fileline(), eqp, tree1p, tree0p);
ifp->user3(1); // So we don't bother to clone it
return ifp;
}
}
void newPslAssertion(AstNode* nodep, AstNode* propp, AstSenTree* sentreep,
AstNode* stmtsp, const string& message) {
propp->unlinkFrBack();
sentreep->unlinkFrBack();
if (stmtsp) stmtsp->unlinkFrBack();
//
AstNode* bodysp = NULL;
bool selfDestruct = false;
if (AstPslCover* snodep = nodep->castPslCover()) {
if (!v3Global.opt.coverageUser()) {
selfDestruct = true;
} else {
// V3Coverage assigned us a bucket to increment.
AstCoverInc* covincp = snodep->coverincp()->castCoverInc();
if (!covincp) snodep->v3fatalSrc("Missing AstCoverInc under assertion");
covincp->unlinkFrBack();
if (message!="") covincp->declp()->comment(message);
bodysp = covincp;
}
} else if (nodep->castPslAssert()) {
bodysp = newFireAssert(nodep,message);
// We assert the property is always true... so report when it fails
// (Note this is opposite the behavior of coverage statements.)
// Need: 'never' operator: not hold in current or any future cycle
propp = new AstLogNot (nodep->fileline(), propp);
} else {
nodep->v3fatalSrc("Unknown node type");
}
if (stmtsp) bodysp = bodysp->addNext(stmtsp);
AstIf* ifp = new AstIf (nodep->fileline(), propp, bodysp, NULL);
bodysp = ifp;
if (nodep->castPslAssert()) ifp->branchPred(AstBranchPred::BP_UNLIKELY);
//
AstNode* newp = new AstAlways (nodep->fileline(),
VAlwaysKwd::ALWAYS,
sentreep,
bodysp);
// Install it
if (selfDestruct) {
// Delete it after making the tree. This way we can tell the user
// if it wasn't constructed nicely or has other errors without needing --coverage.
newp->deleteTree();
nodep->unlinkFrBack();
} else {
nodep->replaceWith(newp);
}
// Bye
pushDeletep(nodep); nodep=NULL;
}
// VISITORS //========== Case assertions
virtual void visit(AstCase* nodep, AstNUser*) {
nodep->iterateChildren(*this);
if (!nodep->user1Inc()) {
bool has_default=false;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
if (itemp->isDefault()) has_default=true;
}
if (nodep->fullPragma() || nodep->priorityPragma()) {
// Simply need to add a default if there isn't one already
++m_statAsFull;
if (!has_default) {
nodep->addItemsp(new AstCaseItem(nodep->fileline(), NULL/*DEFAULT*/,
newFireAssert(nodep, "synthesis full_case, but non-match found")));
}
}
if (nodep->parallelPragma() || nodep->uniquePragma() || nodep->unique0Pragma()) {
// Need to check that one, and only one of the case items match at any moment
// If there's a default, we allow none to match, else exactly one must match
++m_statAsFull;
if (!has_default && !nodep->itemsp()) {
// Not parallel, but harmlessly so.
} else {
AstNode* propp = NULL;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
AstNode* onep = new AstEq(icondp->fileline(),
nodep->exprp()->cloneTree(false),
icondp->cloneTree(false));
if (propp) propp = new AstConcat(icondp->fileline(), onep, propp);
else propp = onep;
}
}
bool allow_none = has_default || nodep->unique0Pragma();
AstNode* ohot = (allow_none
? (new AstOneHot0(nodep->fileline(), propp))->castNode()
: (new AstOneHot (nodep->fileline(), propp))->castNode());
AstIf* ifp = new AstIf (nodep->fileline(),
new AstLogNot (nodep->fileline(), ohot),
newFireAssert(nodep, "synthesis parallel_case, but multiple matches found"),
NULL);
ifp->branchPred(AstBranchPred::BP_UNLIKELY);
nodep->addNotParallelp(ifp);
}
}
}
}
virtual void visit(AstCoverToggle* nodep) {
//nodep->dumpTree(cout,"ct:");
//COVERTOGGLE(INC, ORIG, CHANGE) ->
// IF(ORIG ^ CHANGE) { INC; CHANGE = ORIG; }
AstNode* incp = nodep->incp()->unlinkFrBack();
AstNode* origp = nodep->origp()->unlinkFrBack();
AstNode* changep = nodep->changep()->unlinkFrBack();
AstIf* newp = new AstIf(nodep->fileline(),
new AstXor(nodep->fileline(),
origp,
changep),
incp, NULL);
// We could add another IF to detect posedges, and only increment if so.
// It's another whole branch though verus a potential memory miss.
// We'll go with the miss.
newp->addIfsp(new AstAssign(nodep->fileline(),
changep->cloneTree(false),
origp->cloneTree(false)));
nodep->replaceWith(newp); nodep->deleteTree(); VL_DANGLING(nodep);
}
void newVAssertion(AstVAssert* nodep, AstNode* propp) {
propp->unlinkFrBackWithNext();
AstNode* passsp = nodep->passsp(); if (passsp) passsp->unlinkFrBackWithNext();
AstNode* failsp = nodep->failsp(); if (failsp) failsp->unlinkFrBackWithNext();
//
if (nodep->castVAssert()) {
if (passsp) passsp = newIfAssertOn(passsp);
if (failsp) failsp = newIfAssertOn(failsp);
} else {
nodep->v3fatalSrc("Unknown node type");
}
AstIf* ifp = new AstIf (nodep->fileline(), propp, passsp, failsp);
AstNode* newp = ifp;
if (nodep->castVAssert()) ifp->branchPred(AstBranchPred::BP_UNLIKELY);
//
// Install it
nodep->replaceWith(newp);
// Bye
pushDeletep(nodep); nodep=NULL;
}
static bool
RenderIf(WasmRenderContext& c, AstIf& if_)
{
if (!c.buffer.append("(if "))
return false;
if (!RenderExpr(c, if_.cond()))
return false;
if (!c.buffer.append(" (then "))
return false;
if (!RenderName(c, if_.thenName()))
return false;
c.indent++;
if (!RenderExprList(c, if_.thenExprs()))
return false;
c.indent--;
if (if_.hasElse()) {
if (!c.buffer.append(") (else "))
return false;
if (!RenderName(c, if_.elseName()))
return false;
c.indent++;
if (!RenderExprList(c, if_.elseExprs()))
return false;
c.indent--;
}
return c.buffer.append("))");
}
virtual void visit(AstNodeIf* nodep) {
const ColorSet& colors = m_ifColorp->colors(nodep);
typedef vl_unordered_map<uint32_t, AstNodeIf*> CloneMap;
CloneMap clones;
for (ColorSet::const_iterator color = colors.begin();
color != colors.end(); ++color) {
// Clone this if into its set of split blocks
AstSplitPlaceholder* if_placeholderp = makePlaceholderp();
AstSplitPlaceholder* else_placeholderp = makePlaceholderp();
AstIf* clonep =
new AstIf(nodep->fileline(),
nodep->condp()->cloneTree(true),
if_placeholderp,
else_placeholderp);
AstIf* origp = VN_CAST(nodep, If);
if (origp) {
// Preserve pragmas from unique if's
// so assertions work properly
clonep->uniquePragma(origp->uniquePragma());
clonep->unique0Pragma(origp->unique0Pragma());
clonep->priorityPragma(origp->priorityPragma());
}
clones[*color] = clonep;
m_addAfter[*color]->addNextHere(clonep);
m_addAfter[*color] = if_placeholderp;
}
iterateAndNextNull(nodep->ifsp());
for (ColorSet::const_iterator color = colors.begin();
color != colors.end(); ++color) {
m_addAfter[*color] = clones[*color]->elsesp();
}
iterateAndNextNull(nodep->elsesp());
for (ColorSet::const_iterator color = colors.begin();
color != colors.end(); ++color) {
m_addAfter[*color] = clones[*color];
}
}
void IrGen::visit(AstIf& if_) {
// setup needed basic blocks
Function* functionIr = m_builder.GetInsertBlock()->getParent();
BasicBlock* ThenFirstBB =
BasicBlock::Create(llvmContext, "if_then", functionIr);
BasicBlock* ElseFirstBB = BasicBlock::Create(llvmContext, "if_else");
BasicBlock* MergeBB = BasicBlock::Create(llvmContext, "if_merge");
// current BB:
Value* condIr = callAcceptOn(if_.condition());
assert(condIr);
m_builder.CreateCondBr(condIr, ThenFirstBB, ElseFirstBB);
// thenFirstBB:
m_builder.SetInsertPoint(ThenFirstBB);
Value* thenValue = callAcceptOn(if_.action());
assert(thenValue);
if (!if_.action().objType().isNoreturn()) { m_builder.CreateBr(MergeBB); }
BasicBlock* ThenLastBB = m_builder.GetInsertBlock();
// elseFirstBB:
functionIr->getBasicBlockList().push_back(ElseFirstBB);
m_builder.SetInsertPoint(ElseFirstBB);
Value* elseValue = nullptr;
if (if_.elseAction()) {
elseValue = callAcceptOn(*if_.elseAction());
assert(elseValue);
if (!if_.elseAction()->objType().isNoreturn()) {
m_builder.CreateBr(MergeBB);
}
}
else {
elseValue = m_abstractObject;
m_builder.CreateBr(MergeBB);
}
BasicBlock* ElseLastBB = m_builder.GetInsertBlock();
// mergeBB:
// also sets IrValue of this AstIf
functionIr->getBasicBlockList().push_back(MergeBB);
m_builder.SetInsertPoint(MergeBB);
if (thenValue != m_abstractObject && elseValue != m_abstractObject) {
PHINode* phi = m_builder.CreatePHI(thenValue->getType(), 2, "if_phi");
assert(phi);
phi->addIncoming(thenValue, ThenLastBB);
phi->addIncoming(elseValue, ElseLastBB);
allocateAndInitLocalIrObjectFor(if_, phi);
}
else {
allocateAndInitLocalIrObjectFor(if_, m_abstractObject);
}
}
virtual void visit(AstActive* nodep, AstNUser*) {
// Careful if adding variables here, ACTIVES can be under other ACTIVES
// Need to save and restore any member state in AstUntilStable block
if (!m_topScopep || !nodep->stmtsp()) {
// Not at the top or empty block...
// Only empty blocks should be leftover on the non-top. Killem.
if (nodep->stmtsp()) nodep->v3fatalSrc("Non-empty lower active");
nodep->unlinkFrBack()->deleteTree(); nodep=NULL;
} else {
UINFO(4," ACTIVE "<<nodep<<endl);
AstNode* stmtsp = nodep->stmtsp()->unlinkFrBackWithNext();
if (nodep->hasClocked()) {
// Remember the latest sensitivity so we can compare it next time
if (nodep->hasInitial()) nodep->v3fatalSrc("Initial block should not have clock sensitivity");
if (m_lastSenp && nodep->sensesp()->sameTree(m_lastSenp)) {
UINFO(4," sameSenseTree\n");
} else {
clearLastSen();
m_lastSenp = nodep->sensesp();
// Make a new if statement
m_lastIfp = makeActiveIf(m_lastSenp);
addToEvalLoop(m_lastIfp);
}
// Move statements to if
m_lastIfp->addIfsp(stmtsp);
} else if (nodep->hasInitial()) {
// Don't need to: clearLastSen();, as we're adding it to different cfunc
// Move statements to function
addToInitial(stmtsp);
} else if (nodep->hasSettle()) {
// Don't need to: clearLastSen();, as we're adding it to different cfunc
// Move statements to function
addToSettleLoop(stmtsp);
} else {
// Combo
clearLastSen();
// Move statements to function
addToEvalLoop(stmtsp);
}
nodep->unlinkFrBack()->deleteTree(); nodep = NULL;
}
}
static bool
RenderIf(WasmRenderContext& c, AstIf& if_)
{
if (!RenderExpr(c, if_.cond()))
return false;
if (!RenderIndent(c))
return false;
MAP_AST_EXPR(c, if_);
if (!c.buffer.append("if"))
return false;
if (!RenderBlockNameAndSignature(c, if_.name(), if_.type()))
return false;
if (!c.buffer.append('\n'))
return false;
c.indent++;
if (!RenderExprList(c, if_.thenExprs()))
return false;
c.indent--;
if (if_.hasElse()) {
if (!RenderIndent(c))
return false;
if (!c.buffer.append("else\n"))
return false;
c.indent++;
if (!RenderExprList(c, if_.elseExprs()))
return false;
c.indent--;
}
if (!RenderIndent(c))
return false;
return c.buffer.append("end");
}
void replaceCaseComplicated(AstCase* nodep) {
// CASEx(cexpr,ITEM(icond1,istmts1),ITEM(icond2,istmts2),ITEM(default,istmts3))
// -> IF((cexpr==icond1),istmts1,
// IF((EQ (AND MASK cexpr) (AND MASK icond1)
// ,istmts2, istmts3
AstNode* cexprp = nodep->exprp()->unlinkFrBack();
// We'll do this in two stages. First stage, convert the conditions to
// the appropriate IF AND terms.
if (debug()>=9) nodep->dumpTree(cout," _comp_IN: ");
bool hadDefault = false;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
if (!itemp->condsp()) {
// Default clause. Just make true, we'll optimize it away later
itemp->condsp(new AstConst(itemp->fileline(), AstConst::LogicTrue()));
hadDefault = true;
} else {
// Expressioned clause
AstNode* icondNextp = NULL;
AstNode* ifexprp = NULL; // If expression to test
for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondNextp) {
icondNextp = icondp->nextp();
icondp->unlinkFrBack();
AstNode* condp = NULL; // Default is to use and1p/and2p
AstConst* iconstp = icondp->castConst();
if (iconstp && neverItem(nodep, iconstp)) {
// X in casez can't ever be executed
icondp->deleteTree(); icondp=NULL; iconstp=NULL;
// For simplicity, make expression that is not equal, and let later
// optimizations remove it
condp = new AstConst(itemp->fileline(), AstConst::LogicFalse());
} else if (AstInsideRange* irangep = icondp->castInsideRange()) {
// Similar logic in V3Width::visit(AstInside)
AstNode* ap = AstGte::newTyped(itemp->fileline(),
cexprp->cloneTree(false),
irangep->lhsp()->unlinkFrBack());
AstNode* bp = AstLte::newTyped(itemp->fileline(),
cexprp->cloneTree(false),
irangep->rhsp()->unlinkFrBack());
condp = new AstAnd(itemp->fileline(), ap, bp);
} else if (iconstp && iconstp->num().isFourState()
&& (nodep->casex() || nodep->casez() || nodep->caseInside())) {
V3Number nummask (itemp->fileline(), iconstp->width());
nummask.opBitsNonX(iconstp->num());
V3Number numval (itemp->fileline(), iconstp->width());
numval.opBitsOne(iconstp->num());
AstNode* and1p = new AstAnd(itemp->fileline(), cexprp->cloneTree(false),
new AstConst(itemp->fileline(), nummask));
AstNode* and2p = new AstAnd(itemp->fileline(),
new AstConst(itemp->fileline(), numval),
new AstConst(itemp->fileline(), nummask));
icondp->deleteTree(); icondp=NULL; iconstp=NULL;
condp = AstEq::newTyped(itemp->fileline(), and1p, and2p);
} else {
// Not a caseX mask, we can simply build CASEEQ(cexpr icond)
AstNode* and1p = cexprp->cloneTree(false);
AstNode* and2p = icondp;
condp = AstEq::newTyped(itemp->fileline(), and1p, and2p);
}
if (!ifexprp) {
ifexprp = condp;
} else {
ifexprp = new AstLogOr(itemp->fileline(), ifexprp, condp);
}
}
// Replace expression in tree
itemp->condsp(ifexprp);
}
}
cexprp->deleteTree(); cexprp=NULL;
if (!hadDefault) {
// If there was no default, add a empty one, this greatly simplifies below code
// and constant propagation will just eliminate it for us later.
nodep->addItemsp(new AstCaseItem(nodep->fileline(),
new AstConst(nodep->fileline(), AstConst::LogicTrue()),
NULL));
}
if (debug()>=9) nodep->dumpTree(cout," _comp_COND: ");
// Now build the IF statement tree
// The tree can be quite huge. Pull ever group of 8 out, and make a OR tree.
// This reduces the depth for the bottom elements, at the cost of some of the top elements.
// If we ever have profiling data, we should pull out the most common item from here and
// instead make it the first IF branch.
int depth = 0;
AstNode* grouprootp = NULL;
AstIf* groupnextp = NULL;
AstIf* itemnextp = NULL;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
AstNode* istmtsp = itemp->bodysp(); // Maybe null -- no action.
if (istmtsp) istmtsp->unlinkFrBackWithNext();
// Expressioned clause
AstNode* ifexprp = itemp->condsp()->unlinkFrBack();
{ // Prepare for next group
if (++depth > CASE_ENCODER_GROUP_DEPTH) depth = 1;
if (depth == 1) { // First group or starting new group
itemnextp = NULL;
AstIf* newp = new AstIf(itemp->fileline(), ifexprp->cloneTree(true), NULL, NULL);
if (groupnextp) groupnextp->addElsesp(newp);
else grouprootp = newp;
groupnextp = newp;
} else { // Continue group, modify if condition to OR in this new condition
AstNode* condp = groupnextp->condp()->unlinkFrBack();
groupnextp->condp(new AstOr(ifexprp->fileline(),
condp,
ifexprp->cloneTree(true)));
}
}
{ // Make the new lower IF and attach in the tree
AstNode* itemexprp = ifexprp; ifexprp=NULL;
if (depth == (CASE_ENCODER_GROUP_DEPTH)) { // End of group - can skip the condition
itemexprp->deleteTree(); itemexprp=NULL;
itemexprp = new AstConst(itemp->fileline(), AstConst::LogicTrue());
}
AstIf* newp = new AstIf(itemp->fileline(), itemexprp, istmtsp, NULL);
if (itemnextp) itemnextp->addElsesp(newp);
else groupnextp->addIfsp(newp); // First in a new group
itemnextp = newp;
}
}
if (debug()>=9) nodep->dumpTree(cout," _comp_TREE: ");
// Handle any assertions
replaceCaseParallel(nodep, false);
// Replace the CASE... with IF...
if (debug()>=9) grouprootp->dumpTree(cout," _new: ");
if (grouprootp) nodep->replaceWith(grouprootp);
else nodep->unlinkFrBack();
nodep->deleteTree(); nodep=NULL;
}
AstNode* createDlyArray(AstAssignDly* nodep, AstNode* lhsp) {
// Create delayed assignment
// See top of this file for transformation
// Return the new LHS for the assignment, Null = unlink
// Find selects
AstNode* newlhsp = NULL; // NULL = unlink old assign
AstSel* bitselp = NULL;
AstArraySel* arrayselp = NULL;
if (lhsp->castSel()) {
bitselp = lhsp->castSel();
arrayselp = bitselp->fromp()->castArraySel();
} else {
arrayselp = lhsp->castArraySel();
}
if (!arrayselp) nodep->v3fatalSrc("No arraysel under bitsel?");
if (arrayselp->length()!=1) nodep->v3fatalSrc("ArraySel with length!=1 should have been removed in V3Slice");
UINFO(4,"AssignDlyArray: "<<nodep<<endl);
//
//=== Dimensions: __Vdlyvdim__
deque<AstNode*> dimvalp; // Assignment value for each dimension of assignment
AstNode* dimselp=arrayselp;
for (; dimselp->castArraySel(); dimselp=dimselp->castArraySel()->fromp()) {
AstNode* valp = dimselp->castArraySel()->bitp()->unlinkFrBack();
dimvalp.push_front(valp);
}
AstVarRef* varrefp = dimselp->castVarRef();
if (!varrefp) nodep->v3fatalSrc("No var underneath arraysels\n");
if (!varrefp->varScopep()) varrefp->v3fatalSrc("Var didn't get varscoped in V3Scope.cpp\n");
varrefp->unlinkFrBack();
AstVar* oldvarp = varrefp->varp();
int modVecNum = oldvarp->user4(); oldvarp->user4(modVecNum+1);
//
deque<AstNode*> dimreadps; // Read value for each dimension of assignment
for (unsigned dimension=0; dimension<dimvalp.size(); dimension++) {
AstNode* dimp = dimvalp[dimension];
if (dimp->castConst()) { // bit = const, can just use it
dimreadps.push_front(dimp);
} else {
string bitvarname = (string("__Vdlyvdim")+cvtToStr(dimension)
+"__"+oldvarp->shortName()+"__v"+cvtToStr(modVecNum));
AstVarScope* bitvscp = createVarSc(varrefp->varScopep(), bitvarname, dimp->width());
AstAssign* bitassignp
= new AstAssign (nodep->fileline(),
new AstVarRef(nodep->fileline(), bitvscp, true),
dimp);
nodep->addNextHere(bitassignp);
dimreadps.push_front(new AstVarRef(nodep->fileline(), bitvscp, false));
}
}
//
//=== Bitselect: __Vdlyvlsb__
AstNode* bitreadp=NULL; // Code to read Vdlyvlsb
if (bitselp) {
AstNode* lsbvaluep = bitselp->lsbp()->unlinkFrBack();
if (bitselp->fromp()->castConst()) {// vlsb = constant, can just push constant into where we use it
bitreadp = lsbvaluep;
} else {
string bitvarname = (string("__Vdlyvlsb__")+oldvarp->shortName()+"__v"+cvtToStr(modVecNum));
AstVarScope* bitvscp = createVarSc(varrefp->varScopep(), bitvarname, lsbvaluep->width());
AstAssign* bitassignp = new AstAssign (nodep->fileline(),
new AstVarRef(nodep->fileline(), bitvscp, true),
lsbvaluep);
nodep->addNextHere(bitassignp);
bitreadp = new AstVarRef(nodep->fileline(), bitvscp, false);
}
}
//
//=== Value: __Vdlyvval__
AstNode* valreadp; // Code to read Vdlyvval
if (nodep->rhsp()->castConst()) { // vval = constant, can just push constant into where we use it
valreadp = nodep->rhsp()->unlinkFrBack();
} else {
string valvarname = (string("__Vdlyvval__")+oldvarp->shortName()+"__v"+cvtToStr(modVecNum));
AstVarScope* valvscp = createVarSc(varrefp->varScopep(), valvarname, nodep->rhsp()->width());
newlhsp = new AstVarRef(nodep->fileline(), valvscp, true);
valreadp = new AstVarRef(nodep->fileline(), valvscp, false);
}
//
//=== Setting/not setting boolean: __Vdlyvset__
AstVarScope* setvscp;
AstAssignPre* setinitp = NULL;
if (nodep->user3p()) {
// Simplistic optimization. If the previous statement in same scope was also a =>,
// then we told this nodep->user3 we can use its Vdlyvset rather than making a new one.
// This is good for code like:
// for (i=0; i<5; i++) vector[i] <= something;
setvscp = nodep->user3p()->castNode()->castVarScope();
++m_statSharedSet;
} else { // Create new one
string setvarname = (string("__Vdlyvset__")+oldvarp->shortName()+"__v"+cvtToStr(modVecNum));
setvscp = createVarSc(varrefp->varScopep(), setvarname, 1);
setinitp = new AstAssignPre (nodep->fileline(),
new AstVarRef(nodep->fileline(), setvscp, true),
new AstConst(nodep->fileline(), 0));
AstAssign* setassignp
= new AstAssign (nodep->fileline(),
new AstVarRef(nodep->fileline(), setvscp, true),
new AstConst(nodep->fileline(),
V3Number(nodep->fileline(),1,true)));
nodep->addNextHere(setassignp);
}
if (m_nextDlyp) { // Tell next assigndly it can share the variable
m_nextDlyp->user3p(setvscp);
}
//
// Create ALWAYSPOST for delayed variable
// We add all logic to the same block if it's for the same memory
// This insures that multiple assignments to the same memory will result
// in correctly ordered code - the last assignment must be last.
// It also has the nice side effect of assisting cache locality.
AstNode* selectsp = varrefp;
for (int dimension=int(dimreadps.size())-1; dimension>=0; --dimension) {
selectsp = new AstArraySel(nodep->fileline(), selectsp, dimreadps[dimension]);
}
if (bitselp) {
selectsp = new AstSel(nodep->fileline(), selectsp, bitreadp,
bitselp->widthp()->cloneTree(false));
}
// Build "IF (changeit) ...
UINFO(9," For "<<setvscp<<endl);
UINFO(9," & "<<varrefp<<endl);
AstAlwaysPost* finalp = varrefp->varScopep()->user4p()->castNode()->castAlwaysPost();
if (finalp) {
AstActive* oldactivep = finalp->user2p()->castNode()->castActive();
checkActivePost(varrefp, oldactivep);
if (setinitp) oldactivep->addStmtsp(setinitp);
} else { // first time we've dealt with this memory
finalp = new AstAlwaysPost(nodep->fileline(), NULL/*sens*/, NULL/*body*/);
UINFO(9," Created "<<finalp<<endl);
AstActive* newactp = createActivePost(varrefp);
newactp->addStmtsp(finalp);
varrefp->varScopep()->user4p(finalp);
finalp->user2p(newactp);
if (setinitp) newactp->addStmtsp(setinitp);
}
AstIf* postLogicp;
if (finalp->user3p()->castNode() == setvscp) {
// Optimize as above; if sharing Vdlyvset *ON SAME VARIABLE*,
// we can share the IF statement too
postLogicp = finalp->user4p()->castNode()->castIf();
if (!postLogicp) nodep->v3fatalSrc("Delayed assignment misoptimized; prev var found w/o associated IF");
} else {
postLogicp = new AstIf (nodep->fileline(),
new AstVarRef(nodep->fileline(), setvscp, false),
NULL,
NULL);
UINFO(9," Created "<<postLogicp<<endl);
finalp->addBodysp(postLogicp);
finalp->user3p(setvscp); // Remember IF's vset variable
finalp->user4p(postLogicp); // and the associated IF, as we may be able to reuse it
}
postLogicp->addIfsp(new AstAssign(nodep->fileline(), selectsp, valreadp));
return newlhsp;
}