Examples with TernaryOp org.apache.sysml.hops.TernaryOp used on opensource projects

Example 16 with TernaryOp

use of org.apache.sysml.hops.TernaryOp in project systemml by apache.

the class TemplateCell method rConstructCplan.

protected void rConstructCplan(Hop hop, CPlanMemoTable memo, HashMap<Long, CNode> tmp, HashSet<Hop> inHops, boolean compileLiterals) {
    // memoization for common subexpression elimination and to avoid redundant work
    if (tmp.containsKey(hop.getHopID()))
        return;
    MemoTableEntry me = memo.getBest(hop.getHopID(), TemplateType.CELL);
    // recursively process required childs
    if (me != null && me.type.isIn(TemplateType.ROW, TemplateType.OUTER)) {
        CNodeData cdata = TemplateUtils.createCNodeData(hop, compileLiterals);
        tmp.put(hop.getHopID(), cdata);
        inHops.add(hop);
        return;
    }
    for (int i = 0; i < hop.getInput().size(); i++) {
        Hop c = hop.getInput().get(i);
        if (me != null && me.isPlanRef(i) && !(c instanceof DataOp) && (me.type != TemplateType.MAGG || memo.contains(c.getHopID(), TemplateType.CELL)))
            rConstructCplan(c, memo, tmp, inHops, compileLiterals);
        else if (me != null && (me.type == TemplateType.MAGG || me.type == TemplateType.CELL) && HopRewriteUtils.isMatrixMultiply(hop) && // skip transpose
        i == 0)
            rConstructCplan(c.getInput().get(0), memo, tmp, inHops, compileLiterals);
        else {
            CNodeData cdata = TemplateUtils.createCNodeData(c, compileLiterals);
            tmp.put(c.getHopID(), cdata);
            inHops.add(c);
        }
    }
    // construct cnode for current hop
    CNode out = null;
    if (hop instanceof UnaryOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        String primitiveOpName = ((UnaryOp) hop).getOp().name();
        out = new CNodeUnary(cdata1, UnaryType.valueOf(primitiveOpName));
    } else if (hop instanceof BinaryOp) {
        BinaryOp bop = (BinaryOp) hop;
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
        String primitiveOpName = bop.getOp().name();
        // add lookups if required
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        cdata2 = TemplateUtils.wrapLookupIfNecessary(cdata2, hop.getInput().get(1));
        // construct binary cnode
        out = new CNodeBinary(cdata1, cdata2, BinType.valueOf(primitiveOpName));
    } else if (hop instanceof TernaryOp) {
        TernaryOp top = (TernaryOp) hop;
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
        CNode cdata3 = tmp.get(hop.getInput().get(2).getHopID());
        // add lookups if required
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        cdata2 = TemplateUtils.wrapLookupIfNecessary(cdata2, hop.getInput().get(1));
        cdata3 = TemplateUtils.wrapLookupIfNecessary(cdata3, hop.getInput().get(2));
        // construct ternary cnode, primitive operation derived from OpOp3
        out = new CNodeTernary(cdata1, cdata2, cdata3, TernaryType.valueOf(top.getOp().name()));
    } else if (hop instanceof ParameterizedBuiltinOp) {
        CNode cdata1 = tmp.get(((ParameterizedBuiltinOp) hop).getTargetHop().getHopID());
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        CNode cdata2 = tmp.get(((ParameterizedBuiltinOp) hop).getParameterHop("pattern").getHopID());
        CNode cdata3 = tmp.get(((ParameterizedBuiltinOp) hop).getParameterHop("replacement").getHopID());
        TernaryType ttype = (cdata2.isLiteral() && cdata2.getVarname().equals("Double.NaN")) ? TernaryType.REPLACE_NAN : TernaryType.REPLACE;
        out = new CNodeTernary(cdata1, cdata2, cdata3, ttype);
    } else if (hop instanceof IndexingOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        out = new CNodeTernary(cdata1, TemplateUtils.createCNodeData(new LiteralOp(hop.getInput().get(0).getDim2()), true), TemplateUtils.createCNodeData(hop.getInput().get(4), true), TernaryType.LOOKUP_RC1);
    } else if (HopRewriteUtils.isTransposeOperation(hop)) {
        out = TemplateUtils.skipTranspose(tmp.get(hop.getHopID()), hop, tmp, compileLiterals);
        // correct indexing types of existing lookups
        if (!HopRewriteUtils.containsOp(hop.getParent(), AggBinaryOp.class))
            TemplateUtils.rFlipVectorLookups(out);
        // maintain input hops
        if (out instanceof CNodeData && !inHops.contains(hop.getInput().get(0)))
            inHops.add(hop.getInput().get(0));
    } else if (hop instanceof AggUnaryOp) {
        // aggregation handled in template implementation (note: we do not compile
        // ^2 of SUM_SQ into the operator to simplify the detection of single operators)
        out = tmp.get(hop.getInput().get(0).getHopID());
    } else if (hop instanceof AggBinaryOp) {
        // (1) t(X)%*%X -> sum(X^2) and t(X) %*% Y -> sum(X*Y)
        if (HopRewriteUtils.isTransposeOfItself(hop.getInput().get(0), hop.getInput().get(1))) {
            CNode cdata1 = tmp.get(hop.getInput().get(1).getHopID());
            if (TemplateUtils.isColVector(cdata1))
                cdata1 = new CNodeUnary(cdata1, UnaryType.LOOKUP_R);
            out = new CNodeUnary(cdata1, UnaryType.POW2);
        } else {
            CNode cdata1 = TemplateUtils.skipTranspose(tmp.get(hop.getInput().get(0).getHopID()), hop.getInput().get(0), tmp, compileLiterals);
            if (cdata1 instanceof CNodeData && !inHops.contains(hop.getInput().get(0).getInput().get(0)))
                inHops.add(hop.getInput().get(0).getInput().get(0));
            if (TemplateUtils.isColVector(cdata1))
                cdata1 = new CNodeUnary(cdata1, UnaryType.LOOKUP_R);
            CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
            if (TemplateUtils.isColVector(cdata2))
                cdata2 = new CNodeUnary(cdata2, UnaryType.LOOKUP_R);
            out = new CNodeBinary(cdata1, cdata2, BinType.MULT);
        }
    }
    tmp.put(hop.getHopID(), out);
}

Example 17 with TernaryOp

use of org.apache.sysml.hops.TernaryOp in project systemml by apache.

the class TemplateRow method rConstructCplan.

private void rConstructCplan(Hop hop, CPlanMemoTable memo, HashMap<Long, CNode> tmp, HashSet<Hop> inHops, HashMap<String, Hop> inHops2, boolean compileLiterals) {
    // memoization for common subexpression elimination and to avoid redundant work
    if (tmp.containsKey(hop.getHopID()))
        return;
    // recursively process required childs
    MemoTableEntry me = memo.getBest(hop.getHopID(), TemplateType.ROW, TemplateType.CELL);
    for (int i = 0; i < hop.getInput().size(); i++) {
        Hop c = hop.getInput().get(i);
        if (me != null && me.isPlanRef(i))
            rConstructCplan(c, memo, tmp, inHops, inHops2, compileLiterals);
        else {
            CNodeData cdata = TemplateUtils.createCNodeData(c, compileLiterals);
            tmp.put(c.getHopID(), cdata);
            inHops.add(c);
        }
    }
    // construct cnode for current hop
    CNode out = null;
    if (hop instanceof AggUnaryOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        if (((AggUnaryOp) hop).getDirection() == Direction.Row && HopRewriteUtils.isAggUnaryOp(hop, SUPPORTED_ROW_AGG)) {
            if (hop.getInput().get(0).getDim2() == 1)
                out = (cdata1.getDataType() == DataType.SCALAR) ? cdata1 : new CNodeUnary(cdata1, UnaryType.LOOKUP_R);
            else {
                String opcode = "ROW_" + ((AggUnaryOp) hop).getOp().name().toUpperCase() + "S";
                out = new CNodeUnary(cdata1, UnaryType.valueOf(opcode));
                if (cdata1 instanceof CNodeData && !inHops2.containsKey("X"))
                    inHops2.put("X", hop.getInput().get(0));
            }
        } else if (((AggUnaryOp) hop).getDirection() == Direction.Col && ((AggUnaryOp) hop).getOp() == AggOp.SUM) {
            // vector add without temporary copy
            if (cdata1 instanceof CNodeBinary && ((CNodeBinary) cdata1).getType().isVectorScalarPrimitive())
                out = new CNodeBinary(cdata1.getInput().get(0), cdata1.getInput().get(1), ((CNodeBinary) cdata1).getType().getVectorAddPrimitive());
            else
                out = cdata1;
        } else if (((AggUnaryOp) hop).getDirection() == Direction.RowCol && ((AggUnaryOp) hop).getOp() == AggOp.SUM) {
            out = (cdata1.getDataType().isMatrix()) ? new CNodeUnary(cdata1, UnaryType.ROW_SUMS) : cdata1;
        }
    } else if (hop instanceof AggBinaryOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
        if (HopRewriteUtils.isTransposeOperation(hop.getInput().get(0))) {
            // correct input under transpose
            cdata1 = TemplateUtils.skipTranspose(cdata1, hop.getInput().get(0), tmp, compileLiterals);
            inHops.remove(hop.getInput().get(0));
            if (cdata1 instanceof CNodeData)
                inHops.add(hop.getInput().get(0).getInput().get(0));
            // note: vectorMultAdd applicable to vector-scalar, and vector-vector
            if (hop.getInput().get(1).getDim2() == 1)
                out = new CNodeBinary(cdata1, cdata2, BinType.VECT_MULT_ADD);
            else {
                out = new CNodeBinary(cdata1, cdata2, BinType.VECT_OUTERMULT_ADD);
                if (!inHops2.containsKey("B1")) {
                    // incl modification of X for consistency
                    if (cdata1 instanceof CNodeData)
                        inHops2.put("X", hop.getInput().get(0).getInput().get(0));
                    inHops2.put("B1", hop.getInput().get(1));
                }
            }
            if (!inHops2.containsKey("X"))
                inHops2.put("X", hop.getInput().get(0).getInput().get(0));
        } else {
            if (hop.getInput().get(0).getDim2() == 1 && hop.getInput().get(1).getDim2() == 1)
                out = new CNodeBinary((cdata1.getDataType() == DataType.SCALAR) ? cdata1 : new CNodeUnary(cdata1, UnaryType.LOOKUP0), (cdata2.getDataType() == DataType.SCALAR) ? cdata2 : new CNodeUnary(cdata2, UnaryType.LOOKUP0), BinType.MULT);
            else if (hop.getInput().get(1).getDim2() == 1) {
                out = new CNodeBinary(cdata1, cdata2, BinType.DOT_PRODUCT);
                inHops2.put("X", hop.getInput().get(0));
            } else {
                out = new CNodeBinary(cdata1, cdata2, BinType.VECT_MATRIXMULT);
                inHops2.put("X", hop.getInput().get(0));
                inHops2.put("B1", hop.getInput().get(1));
            }
        }
    } else if (HopRewriteUtils.isTransposeOperation(hop)) {
        out = TemplateUtils.skipTranspose(tmp.get(hop.getHopID()), hop, tmp, compileLiterals);
        if (out instanceof CNodeData && !inHops.contains(hop.getInput().get(0)))
            inHops.add(hop.getInput().get(0));
    } else if (hop instanceof UnaryOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        // if one input is a matrix then we need to do vector by scalar operations
        if (hop.getInput().get(0).getDim1() >= 1 && hop.getInput().get(0).getDim2() > 1 || (!hop.dimsKnown() && cdata1.getDataType() == DataType.MATRIX)) {
            if (HopRewriteUtils.isUnary(hop, SUPPORTED_VECT_UNARY)) {
                String opname = "VECT_" + ((UnaryOp) hop).getOp().name();
                out = new CNodeUnary(cdata1, UnaryType.valueOf(opname));
                if (cdata1 instanceof CNodeData && !inHops2.containsKey("X"))
                    inHops2.put("X", hop.getInput().get(0));
            } else
                throw new RuntimeException("Unsupported unary matrix " + "operation: " + ((UnaryOp) hop).getOp().name());
        } else // general scalar case
        {
            cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
            String primitiveOpName = ((UnaryOp) hop).getOp().toString();
            out = new CNodeUnary(cdata1, UnaryType.valueOf(primitiveOpName));
        }
    } else if (HopRewriteUtils.isBinary(hop, OpOp2.CBIND)) {
        // special case for cbind with zeros
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = null;
        if (HopRewriteUtils.isDataGenOpWithConstantValue(hop.getInput().get(1))) {
            cdata2 = TemplateUtils.createCNodeData(HopRewriteUtils.getDataGenOpConstantValue(hop.getInput().get(1)), true);
            // rm 0-matrix
            inHops.remove(hop.getInput().get(1));
        } else {
            cdata2 = tmp.get(hop.getInput().get(1).getHopID());
            cdata2 = TemplateUtils.wrapLookupIfNecessary(cdata2, hop.getInput().get(1));
        }
        out = new CNodeBinary(cdata1, cdata2, BinType.VECT_CBIND);
        if (cdata1 instanceof CNodeData && !inHops2.containsKey("X"))
            inHops2.put("X", hop.getInput().get(0));
    } else if (hop instanceof BinaryOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
        // if one input is a matrix then we need to do vector by scalar operations
        if ((hop.getInput().get(0).getDim1() >= 1 && hop.getInput().get(0).getDim2() > 1) || (hop.getInput().get(1).getDim1() >= 1 && hop.getInput().get(1).getDim2() > 1) || (!(hop.dimsKnown() && hop.getInput().get(0).dimsKnown() && hop.getInput().get(1).dimsKnown()) && // not a known vector output
        (hop.getDim2() != 1) && (cdata1.getDataType().isMatrix() || cdata2.getDataType().isMatrix()))) {
            if (HopRewriteUtils.isBinary(hop, SUPPORTED_VECT_BINARY)) {
                if (TemplateUtils.isMatrix(cdata1) && (TemplateUtils.isMatrix(cdata2) || TemplateUtils.isRowVector(cdata2))) {
                    String opname = "VECT_" + ((BinaryOp) hop).getOp().name();
                    out = new CNodeBinary(cdata1, cdata2, BinType.valueOf(opname));
                } else {
                    String opname = "VECT_" + ((BinaryOp) hop).getOp().name() + "_SCALAR";
                    if (TemplateUtils.isColVector(cdata1))
                        cdata1 = new CNodeUnary(cdata1, UnaryType.LOOKUP_R);
                    if (TemplateUtils.isColVector(cdata2))
                        cdata2 = new CNodeUnary(cdata2, UnaryType.LOOKUP_R);
                    out = new CNodeBinary(cdata1, cdata2, BinType.valueOf(opname));
                }
                if (cdata1 instanceof CNodeData && !inHops2.containsKey("X") && !(cdata1.getDataType() == DataType.SCALAR)) {
                    inHops2.put("X", hop.getInput().get(0));
                }
            } else
                throw new RuntimeException("Unsupported binary matrix " + "operation: " + ((BinaryOp) hop).getOp().name());
        } else // one input is a vector/scalar other is a scalar
        {
            String primitiveOpName = ((BinaryOp) hop).getOp().toString();
            if (TemplateUtils.isColVector(cdata1))
                cdata1 = new CNodeUnary(cdata1, UnaryType.LOOKUP_R);
            if (// vector or vector can be inferred from lhs
            TemplateUtils.isColVector(cdata2) || (TemplateUtils.isColVector(hop.getInput().get(0)) && cdata2 instanceof CNodeData && hop.getInput().get(1).getDataType().isMatrix()))
                cdata2 = new CNodeUnary(cdata2, UnaryType.LOOKUP_R);
            out = new CNodeBinary(cdata1, cdata2, BinType.valueOf(primitiveOpName));
        }
    } else if (hop instanceof TernaryOp) {
        TernaryOp top = (TernaryOp) hop;
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        CNode cdata2 = tmp.get(hop.getInput().get(1).getHopID());
        CNode cdata3 = tmp.get(hop.getInput().get(2).getHopID());
        // add lookups if required
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        cdata3 = TemplateUtils.wrapLookupIfNecessary(cdata3, hop.getInput().get(2));
        // construct ternary cnode, primitive operation derived from OpOp3
        out = new CNodeTernary(cdata1, cdata2, cdata3, TernaryType.valueOf(top.getOp().toString()));
    } else if (HopRewriteUtils.isNary(hop, OpOpN.CBIND)) {
        CNode[] inputs = new CNode[hop.getInput().size()];
        for (int i = 0; i < hop.getInput().size(); i++) {
            Hop c = hop.getInput().get(i);
            CNode cdata = tmp.get(c.getHopID());
            if (TemplateUtils.isColVector(cdata) || TemplateUtils.isRowVector(cdata))
                cdata = TemplateUtils.wrapLookupIfNecessary(cdata, c);
            inputs[i] = cdata;
            if (i == 0 && cdata instanceof CNodeData && !inHops2.containsKey("X"))
                inHops2.put("X", c);
        }
        out = new CNodeNary(inputs, NaryType.VECT_CBIND);
    } else if (hop instanceof ParameterizedBuiltinOp) {
        CNode cdata1 = tmp.get(((ParameterizedBuiltinOp) hop).getTargetHop().getHopID());
        cdata1 = TemplateUtils.wrapLookupIfNecessary(cdata1, hop.getInput().get(0));
        CNode cdata2 = tmp.get(((ParameterizedBuiltinOp) hop).getParameterHop("pattern").getHopID());
        CNode cdata3 = tmp.get(((ParameterizedBuiltinOp) hop).getParameterHop("replacement").getHopID());
        TernaryType ttype = (cdata2.isLiteral() && cdata2.getVarname().equals("Double.NaN")) ? TernaryType.REPLACE_NAN : TernaryType.REPLACE;
        out = new CNodeTernary(cdata1, cdata2, cdata3, ttype);
    } else if (hop instanceof IndexingOp) {
        CNode cdata1 = tmp.get(hop.getInput().get(0).getHopID());
        out = new CNodeTernary(cdata1, TemplateUtils.createCNodeData(new LiteralOp(hop.getInput().get(0).getDim2()), true), TemplateUtils.createCNodeData(hop.getInput().get(4), true), (hop.getDim2() != 1) ? TernaryType.LOOKUP_RVECT1 : TernaryType.LOOKUP_RC1);
    }
    if (out == null) {
        throw new RuntimeException(hop.getHopID() + " " + hop.getOpString());
    }
    if (out.getDataType().isMatrix()) {
        out.setNumRows(hop.getDim1());
        out.setNumCols(hop.getDim2());
    }
    tmp.put(hop.getHopID(), out);
}

Example 18 with TernaryOp

use of org.apache.sysml.hops.TernaryOp in project systemml by apache.

the class RewriteAlgebraicSimplificationStatic method simplifyReverseOperation.

/**
 * NOTE: this would be by definition a dynamic rewrite; however, we apply it as a static
 * rewrite in order to apply it before splitting dags which would hide the table information
 * if dimensions are not specified.
 *
 * @param parent parent high-level operator
 * @param hi high-level operator
 * @param pos position
 * @return high-level operator
 */
private static Hop simplifyReverseOperation(Hop parent, Hop hi, int pos) {
    if (hi instanceof AggBinaryOp && hi.getInput().get(0) instanceof TernaryOp) {
        TernaryOp top = (TernaryOp) hi.getInput().get(0);
        if (top.getOp() == OpOp3.CTABLE && HopRewriteUtils.isBasic1NSequence(top.getInput().get(0)) && HopRewriteUtils.isBasicN1Sequence(top.getInput().get(1)) && top.getInput().get(0).getDim1() == top.getInput().get(1).getDim1()) {
            ReorgOp rop = HopRewriteUtils.createReorg(hi.getInput().get(1), ReOrgOp.REV);
            HopRewriteUtils.replaceChildReference(parent, hi, rop, pos);
            HopRewriteUtils.cleanupUnreferenced(hi, top);
            hi = rop;
            LOG.debug("Applied simplifyReverseOperation.");
        }
    }
    return hi;
}

Example 19 with TernaryOp

use of org.apache.sysml.hops.TernaryOp in project systemml by apache.

the class RewriteSplitDagDataDependentOperators method rCollectDataDependentOperators.

private void rCollectDataDependentOperators(Hop hop, ArrayList<Hop> cand) {
    if (hop.isVisited())
        return;
    // prevent unnecessary dag split (dims known or no consumer operations)
    boolean noSplitRequired = (hop.dimsKnown() || HopRewriteUtils.hasOnlyWriteParents(hop, true, true));
    boolean investigateChilds = true;
    // #1 removeEmpty
    if (hop instanceof ParameterizedBuiltinOp && ((ParameterizedBuiltinOp) hop).getOp() == ParamBuiltinOp.RMEMPTY && !noSplitRequired && !(hop.getParent().size() == 1 && hop.getParent().get(0) instanceof TernaryOp && ((TernaryOp) hop.getParent().get(0)).isMatrixIgnoreZeroRewriteApplicable())) {
        ParameterizedBuiltinOp pbhop = (ParameterizedBuiltinOp) hop;
        cand.add(pbhop);
        investigateChilds = false;
        // keep interesting consumer information, flag hops accordingly
        boolean noEmptyBlocks = true;
        boolean onlyPMM = true;
        boolean diagInput = pbhop.isTargetDiagInput();
        for (Hop p : hop.getParent()) {
            // list of operators without need for empty blocks to be extended as needed
            noEmptyBlocks &= (p instanceof AggBinaryOp && hop == p.getInput().get(0) || HopRewriteUtils.isUnary(p, OpOp1.NROW));
            onlyPMM &= (p instanceof AggBinaryOp && hop == p.getInput().get(0));
        }
        pbhop.setOutputEmptyBlocks(!noEmptyBlocks);
        if (onlyPMM && diagInput) {
            if (ConfigurationManager.isDynamicRecompilation())
                pbhop.setOutputPermutationMatrix(true);
            for (Hop p : hop.getParent()) ((AggBinaryOp) p).setHasLeftPMInput(true);
        }
    }
    // #2 ctable with unknown dims
    if (HopRewriteUtils.isTernary(hop, OpOp3.CTABLE) && // dims not provided
    hop.getInput().size() < 4 && !noSplitRequired) {
        cand.add(hop);
        investigateChilds = false;
        // keep interesting consumer information, flag hops accordingly
        boolean onlyPMM = true;
        for (Hop p : hop.getParent()) {
            onlyPMM &= (p instanceof AggBinaryOp && hop == p.getInput().get(0));
        }
        if (onlyPMM && HopRewriteUtils.isBasic1NSequence(hop.getInput().get(0)))
            hop.setOutputEmptyBlocks(false);
    }
    // #3 orderby childs computed in same DAG
    if (HopRewriteUtils.isReorg(hop, ReOrgOp.SORT)) {
        // params 'decreasing' / 'indexreturn'
        for (int i = 2; i <= 3; i++) {
            Hop c = hop.getInput().get(i);
            if (!(c instanceof LiteralOp || c instanceof DataOp)) {
                cand.add(c);
                c.setVisited();
                investigateChilds = false;
            }
        }
    }
    // #4 second-order eval function
    if (HopRewriteUtils.isNary(hop, OpOpN.EVAL) && !noSplitRequired) {
        cand.add(hop);
        investigateChilds = false;
    }
    // otherwise, processed by recursive rule application)
    if (investigateChilds && hop.getInput() != null)
        for (Hop c : hop.getInput()) rCollectDataDependentOperators(c, cand);
    hop.setVisited();
}