Esempio n. 1
0
    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);
	    }
	}
    }
Esempio n. 2
0
    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);
	    }
	}
    }
Esempio n. 3
0
    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);
	    }
	}
    }
Esempio n. 4
0
    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);
	    }
	}
    }