/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012-2015 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.vm4brwsr;

 final class NumberOperations {

     private static final int DIV32 = 1;

     private static final int MOD32 = 2;

     private static final int MUL32 = 4;

     private int used;

     public String mul32() {

         used |= MUL32;

         return "__mul32(@1,@2)";

     }

     public String div32() {

         used |= DIV32;

         return "__div32(@1,@2)";

     }

     public String mod32() {

         used |= MOD32;

         return "__mod32(@1,@2)";

     }

     public String generate() {

         if (used == 0) {

             return "";

         }

         StringBuilder sb = new StringBuilder();

         if ((used & MUL32) != 0) {

             sb.append(

                 "    __mul32 = function(x, y) {\n" +

                 "        return (((x * (y >> 16)) << 16) + x * (y & 0xFFFF)) | 0;\n" +

                 "    };\n" +

                 ""

             );

         }

         if ((used & (MOD32 | DIV32)) != 0) {

             sb.append(

                 "    function __handleDivByZero() {\n" +

                 "        var exception = new vm.java_lang_ArithmeticException;\n" +

                 "        vm.java_lang_ArithmeticException(false).constructor\n" +

                 "          .cons__VLjava_lang_String_2.call(exception, \"/ by zero\");\n" +

                 "\n" +

                 "        throw exception;\n" +

                 "    }\n" +

                 ""

             );

         }

         if ((used & MOD32) != 0) {

             sb.append(

                 "    function __mod32(x, y) {\n" +

                 "        if (y === 0) __handleDivByZero();\n" +

                 "        return (x % y) | 0;\n" +

                 "    }\n" +

                 ""

             );

         }

         if ((used & DIV32) != 0) {

             sb.append(

                 "    function __div32(x, y) {\n" +

                 "        if (y === 0) __handleDivByZero();\n" +

                 "        return (x / y) | 0;\n" +

                 "    }\n" +

                 ""

             );

         }

         return sb.toString();

     }

 }