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Fix assignments of {a,b,c} = {c,b,a}

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git-svn-id: file://localhost/svn/verilator/trunk/verilator@988 77ca24e4-aefa-0310-84f0-b9a241c72d87
This commit is contained in:
Wilson Snyder
2008-02-20 16:54:41 +00:00
parent 98fff6a4ce
commit b4d9ccd9af
6 changed files with 305 additions and 12 deletions
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src/V3Const.cpp
+115 -11
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@@ -39,11 +39,63 @@
#include "V3Width.h"
#include "V3Signed.h"
//######################################################################
// Utilities
class ConstVarMarkVisitor : public AstNVisitor {
// NODE STATE
// AstVar::userp -> bool, Var marked, 0=not set yet
private:
// VISITORS
virtual void visit(AstVarRef* nodep, AstNUser*) {
if (nodep->varp()) nodep->varp()->user(1);
}
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
ConstVarMarkVisitor(AstNode* nodep) {
AstNode::userClearTree();
nodep->iterateAndNext(*this, NULL);
}
virtual ~ConstVarMarkVisitor() {}
};
class ConstVarFindVisitor : public AstNVisitor {
// NODE STATE
// AstVar::userp -> bool, input from ConstVarMarkVisitor
// MEMBERS
bool m_found;
private:
// VISITORS
virtual void visit(AstVarRef* nodep, AstNUser*) {
if (nodep->varp() && nodep->varp()->user()) m_found = true;
}
virtual void visit(AstNode* nodep, AstNUser*) {
nodep->iterateChildren(*this);
}
public:
// CONSTUCTORS
ConstVarFindVisitor(AstNode* nodep) {
m_found = false;
nodep->iterateAndNext(*this, NULL);
}
virtual ~ConstVarFindVisitor() {}
// METHODS
bool found() const { return m_found; }
};
//######################################################################
// Const state, as a visitor of each AstNode
class ConstVisitor : public AstNVisitor {
private:
// NODE STATE
// ** only when m_warn is set. If state is needed other times,
// ** must track down everywhere V3Const is called and make sure no overlaps.
// AstVar::userp -> Used by ConstVarMarkVisitor/ConstVarFindVisitor
// STATE
bool m_params; // If true, propogate parameterized and true numbers only
bool m_required; // If true, must become a constant
@@ -494,10 +546,26 @@ private:
}
}
else if (!m_cpp && nodep->lhsp()->castConcat()) {
UINFO(4," ASSI "<<nodep<<endl);
bool need_temp = false;
if (m_warn && !nodep->castAssignDly()) { // Is same var on LHS and RHS?
ConstVarMarkVisitor mark(nodep->lhsp());
ConstVarFindVisitor find(nodep->rhsp());
if (find.found()) need_temp = true;
}
if (need_temp) {
// The first time we constify, there may be the same variable on the LHS
// and RHS. In that case, we must use temporaries, or {a,b}={b,a} will break.
UINFO(4," ASSITEMP "<<nodep<<endl);
// ASSIGN(CONCAT(lc1,lc2),rhs) -> ASSIGN(temp1,SEL(rhs,{size})),
// ASSIGN(temp2,SEL(newrhs,{size}))
// ASSIGN(lc1,temp1),
// ASSIGN(lc2,temp2)
} else {
UINFO(4," ASSI "<<nodep<<endl);
// ASSIGN(CONCAT(lc1,lc2),rhs) -> ASSIGN(lc1,SEL(rhs,{size})),
// ASSIGN(lc2,SEL(newrhs,{size}))
}
if (debug()>=9) nodep->dumpTree(cout," Ass_old: ");
// ASSIGN(CONCAT(lc1,lc2),rhs) -> ASSIGN(lc1,SEL(rhs,{size})),
// ASSIGN(lc2,SEL(newrhs,{size}))
// Unlink the stuff
AstNode* lc1p = nodep->lhsp()->castConcat()->lhsp()->unlinkFrBack();
AstNode* lc2p = nodep->lhsp()->castConcat()->rhsp()->unlinkFrBack();
@@ -517,14 +585,50 @@ private:
sel2p->width(msb2-lsb2+1,msb2-lsb2+1);
// Make new assigns of same flavor as old one
//*** Not cloneTree; just one node.
AstNodeAssign* asn1p=nodep->cloneType(lc1p, sel1p)->castNodeAssign();
AstNodeAssign* asn2p=nodep->cloneType(lc2p, sel2p)->castNodeAssign();
asn1p->width(msb1-lsb1+1,msb1-lsb1+1);
asn2p->width(msb2-lsb2+1,msb2-lsb2+1);
nodep->addNextHere(asn1p);
nodep->addNextHere(asn2p);
if (debug()>=9) asn1p->dumpTree(cout," _new: ");
if (debug()>=9) asn2p->dumpTree(cout," _new: ");
AstNode* newp = NULL;
if (!need_temp) {
AstNodeAssign* asn1ap=nodep->cloneType(lc1p, sel1p)->castNodeAssign();
AstNodeAssign* asn2ap=nodep->cloneType(lc2p, sel2p)->castNodeAssign();
asn1ap->width(msb1-lsb1+1,msb1-lsb1+1);
asn2ap->width(msb2-lsb2+1,msb2-lsb2+1);
newp = newp->addNext(asn1ap);
newp = newp->addNext(asn2ap);
} else {
if (!m_modp) nodep->v3fatalSrc("Not under module");
// We could create just one temp variable, but we'll get better optimization
// if we make one per term.
string name1 = ((string)"__Vconcswap__"+cvtToStr(m_modp->varNumGetInc()));
string name2 = ((string)"__Vconcswap__"+cvtToStr(m_modp->varNumGetInc()));
AstVar* temp1p = new AstVar(sel1p->fileline(), AstVarType::BLOCKTEMP, name1,
new AstRange(sel1p->fileline(), msb1-lsb1, 0));
AstVar* temp2p = new AstVar(sel2p->fileline(), AstVarType::BLOCKTEMP, name2,
new AstRange(sel2p->fileline(), msb2-lsb2, 0));
m_modp->addStmtp(temp1p);
m_modp->addStmtp(temp2p);
AstNodeAssign* asn1ap=nodep->cloneType
(new AstVarRef(sel1p->fileline(), temp1p, true),
sel1p)->castNodeAssign();
AstNodeAssign* asn2ap=nodep->cloneType
(new AstVarRef(sel2p->fileline(), temp2p, true),
sel2p)->castNodeAssign();
AstNodeAssign* asn1bp=nodep->cloneType
(lc1p, new AstVarRef(sel1p->fileline(), temp1p, false))
->castNodeAssign();
AstNodeAssign* asn2bp=nodep->cloneType
(lc2p, new AstVarRef(sel2p->fileline(), temp2p, false))
->castNodeAssign();
asn1ap->width(msb1-lsb1+1,msb1-lsb1+1);
asn1bp->width(msb1-lsb1+1,msb1-lsb1+1);
asn2ap->width(msb2-lsb2+1,msb2-lsb2+1);
asn2bp->width(msb2-lsb2+1,msb2-lsb2+1);
// This order matters
newp = newp->addNext(asn1ap);
newp = newp->addNext(asn2ap);
newp = newp->addNext(asn1bp);
newp = newp->addNext(asn2bp);
}
if (debug()>=9) newp->dumpTreeAndNext(cout," _new: ");
nodep->addNextHere(newp);
// Cleanup
nodep->unlinkFrBack()->deleteTree(); nodep=NULL;
conp->deleteTree(); conp=NULL;