bool isCaseTreeFast(AstCase* nodep) {
int width = 0;
bool opaque = false;
m_caseItems = 0;
m_caseNoOverlapsAllCovered = true;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
if (icondp->width() > width) width = icondp->width();
if (icondp->isDouble()) opaque = true;
if (!icondp->castConst()) width = CASE_BARF; // Can't parse; not a constant
m_caseItems++;
}
}
m_caseWidth = width;
if (width==0 || width > CASE_OVERLAP_WIDTH || opaque) {
m_caseNoOverlapsAllCovered = false;
return false; // Too wide for analysis
}
UINFO(8,"Simple case statement: "<<nodep<<endl);
// Zero list of items for each value
for (uint32_t i=0; i<(1UL<<m_caseWidth); i++) m_valueItem[i] = NULL;
// Now pick up the values for each assignment
// We can cheat and use uint32_t's because we only support narrow case's
bool bitched = false;
for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
//if (debug()>=9) icondp->dumpTree(cout," caseitem: ");
AstConst* iconstp = icondp->castConst();
if (!iconstp) nodep->v3fatalSrc("above 'can't parse' should have caught this\n");
if (neverItem(nodep, iconstp)) {
// X in casez can't ever be executed
} else {
V3Number nummask (itemp->fileline(), iconstp->width());
nummask.opBitsNonX(iconstp->num());
uint32_t mask = nummask.toUInt();
V3Number numval (itemp->fileline(), iconstp->width());
numval.opBitsOne(iconstp->num());
uint32_t val = numval.toUInt();
for (uint32_t i=0; i<(1UL<<m_caseWidth); i++) {
if ((i & mask) == val) {
if (!m_valueItem[i]) {
m_valueItem[i] = itemp;
} else if (!itemp->ignoreOverlap() && !bitched) {
itemp->v3warn(CASEOVERLAP,"Case values overlap (example pattern 0x"<<hex<<i<<")");
bitched = true;
m_caseNoOverlapsAllCovered = false;
}
}
}
}
}
// Defaults were moved to last in the caseitem list by V3LinkDot
if (itemp->isDefault()) { // Case statement's default... Fill the table
for (uint32_t i=0; i<(1UL<<m_caseWidth); i++) {
if (!m_valueItem[i]) m_valueItem[i] = itemp;
}
}
}
for (uint32_t i=0; i<(1UL<<m_caseWidth); i++) {
if (!m_valueItem[i]) {
nodep->v3warn(CASEINCOMPLETE,"Case values incompletely covered (example pattern 0x"<<hex<<i<<")");
m_caseNoOverlapsAllCovered = false;
return false;
}
}
if (m_caseItems <= 3) return false; // Not worth simplifing
// Convert valueItem from AstCaseItem* to the expression
// Not done earlier, as we may now have a NULL because it's just a ";" NOP branch
for (uint32_t i=0; i<(1UL<<m_caseWidth); i++) {
m_valueItem[i] = m_valueItem[i]->castCaseItem()->bodysp();
}
return true; // All is fine
}
