System.Xml.Xsl.IlGen.XmlILVisitor.Compare C# (CSharp) Method

        private void Compare(QilBinary ndComp) {
            QilNodeType relOp = ndComp.NodeType;
            XmlTypeCode code;
            Debug.Assert(ndComp.Left.XmlType.IsAtomicValue && ndComp.Right.XmlType.IsAtomicValue, "Operands to compare must be atomic values.");
            Debug.Assert(ndComp.Left.XmlType.IsSingleton && ndComp.Right.XmlType.IsSingleton, "Operands to compare must be cardinality one.");
            Debug.Assert(ndComp.Left.XmlType == ndComp.Right.XmlType, "Operands to compare may not be heterogenous.");

            if (relOp == QilNodeType.Eq || relOp == QilNodeType.Ne) {
                // Generate better code for certain special cases
                if (TryZeroCompare(relOp, ndComp.Left, ndComp.Right))
                    return;

                if (TryZeroCompare(relOp, ndComp.Right, ndComp.Left))
                    return;

                if (TryNameCompare(relOp, ndComp.Left, ndComp.Right))
                    return;

                if (TryNameCompare(relOp, ndComp.Right, ndComp.Left))
                    return;
            }

            // Push two operands onto the stack
            NestedVisitEnsureStack(ndComp.Left, ndComp.Right);

            // Perform comparison
            code = ndComp.Left.XmlType.TypeCode;
            switch (code) {
                case XmlTypeCode.String:
                case XmlTypeCode.Decimal:
                case XmlTypeCode.QName:
                    if (relOp == QilNodeType.Eq || relOp == QilNodeType.Ne) {
                        this.helper.CallCompareEquals(code);

                        // If relOp is Eq, then branch to true label or push "true" if Equals function returns true (non-zero)
                        // If relOp is Ne, then branch to true label or push "true" if Equals function returns false (zero)
                        ZeroCompare((relOp == QilNodeType.Eq) ? QilNodeType.Ne : QilNodeType.Eq, true);
                    }
                    else {
                        Debug.Assert(code != XmlTypeCode.QName, "QName values do not support the " + relOp + " operation");

                        // Push -1, 0, or 1 onto the stack depending upon the result of the comparison
                        this.helper.CallCompare(code);

                        // Compare result to 0 (e.g. Ge is >= 0)
                        this.helper.Emit(OpCodes.Ldc_I4_0);
                        ClrCompare(relOp, code);
                    }
                    break;

                case XmlTypeCode.Integer:
                case XmlTypeCode.Int:
                case XmlTypeCode.Boolean:
                case XmlTypeCode.Double:
                    ClrCompare(relOp, code);
                    break;

                default:
                    Debug.Fail("Comparisons for datatype " + code + " are invalid.");
                    break;
            }
        }