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27
28// Ensure that we can correctly change the sign of the most negative smi.
29
30// Possible Smi ranges.
31var ranges = [{min: -1073741824, max: 1073741823, bits: 31},
32              {min: -2147483648, max: 2147483647, bits: 32}];
33
34for (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