1 // Copyright 2008 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 // Ensure that we can correctly change the sign of the most negative smi. 29 30 // Possible Smi ranges. 31 var ranges = [{min: -1073741824, max: 1073741823, bits: 31}, 32 {min: -2147483648, max: 2147483647, bits: 32}]; 33 34 for (var i = 0; i < ranges.length; i++) { 35 var range = ranges[i]; 36 var min_smi = range.min; 37 var max_smi = range.max; 38 var bits = range.bits; 39 var name = bits + "-bit"; 40 41 var result = max_smi + 1; 42 43 // Min smi as literal 44 assertEquals(result, eval(min_smi + " * -1"), name + "-litconmult"); 45 assertEquals(result, eval(min_smi + " / -1"), name + "-litcondiv"); 46 assertEquals(result, eval("-(" + min_smi + ")"), name + "-litneg"); 47 assertEquals(result, eval("0 - (" + min_smi + ")")), name + "-conlitsub"; 48 49 // As variable: 50 assertEquals(result, min_smi * -1, name + "-varconmult"); 51 assertEquals(result, min_smi / -1, name + "-varcondiv"); 52 assertEquals(result, -min_smi, name + "-varneg"); 53 assertEquals(result, 0 - min_smi, name + "-convarsub"); 54 55 // Only variables: 56 var zero = 0; 57 var minus_one = -1; 58 59 assertEquals(result, min_smi * minus_one, name + "-varvarmult"); 60 assertEquals(result, min_smi / minus_one, name + "-varvardiv"); 61 assertEquals(result, zero - min_smi, name + "-varvarsub"); 62 63 // Constants as variables 64 assertEquals(result, eval(min_smi + " * minus_one"), name + "-litvarmult"); 65 assertEquals(result, eval(min_smi + " / minus_one"), name + "-litvarmdiv"); 66 assertEquals(result, eval("0 - (" + min_smi + ")"), name + "-varlitsub"); 67 68 var half_min_smi = -(1 << (bits >> 1)); 69 var half_max_smi = 1 << ((bits - 1) >> 1); 70 71 assertEquals(max_smi + 1, -half_min_smi * half_max_smi, name + "-half1"); 72 assertEquals(max_smi + 1, half_min_smi * -half_max_smi, name + "-half2"); 73 assertEquals(max_smi + 1, half_max_smi * -half_min_smi, name + "-half3"); 74 assertEquals(max_smi + 1, -half_max_smi * half_min_smi, name + "-half4"); 75 } 76