void createDeepTemp(AstNode* nodep) {
UINFO(6," Deep "<<nodep<<endl);
//if (debug()>=9) nodep->dumpTree(cout,"deep:");
string newvarname = ((string)"__Vdeeptemp"+cvtToStr(m_modp->varNumGetInc()));
AstVar* varp = new AstVar (nodep->fileline(), AstVarType::STMTTEMP, newvarname,
// Width, not widthMin, as we may be in middle of BITSEL expression which
// though it's one bit wide, needs the mask in the upper bits.
// (Someday we'll have a valid bitmask instead of widths....)
// See t_func_crc for an example test that requires this
VFlagLogicPacked(), nodep->width());
if (!m_funcp) nodep->v3fatalSrc("Deep expression not under a function");
m_funcp->addInitsp(varp);
// Replace node tree with reference to var
AstVarRef* newp = new AstVarRef (nodep->fileline(), varp, false);
nodep->replaceWith(newp);
// Put assignment before the referencing statement
AstAssign* assp = new AstAssign (nodep->fileline(),
new AstVarRef(nodep->fileline(), varp, true),
nodep);
AstNRelinker linker2;
m_stmtp->unlinkFrBack(&linker2);
assp->addNext(m_stmtp);
linker2.relink(assp);
}
AstVar* getBlockTemp(AstNode* nodep) {
string newvarname = ((string)"__Vtemp"+cvtToStr(m_modp->varNumGetInc()));
AstVar* varp = new AstVar (nodep->fileline(), AstVarType::STMTTEMP, newvarname,
nodep->dtypep());
m_funcp->addInitsp(varp);
return varp;
}
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(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);
}
}
}
