js/src/tests/ecma_6/Math/fround.js@129ffea94266
js/src/tests/ecma_6/Math/fround.js
Sat, 03 Jan 2015 20:18:00 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Sat, 03 Jan 2015 20:18:00 +0100
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
- permissions
- -rw-r--r--
Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.
1 /*
2 * Any copyright is dedicated to the Public Domain.
3 * http://creativecommons.org/licenses/publicdomain/
4 */
6 // Some tests regarding conversion to Float32
7 assertEq(Math.fround(), NaN);
9 // Special values
10 assertEq(Math.fround(NaN), NaN);
11 assertEq(Math.fround(-Infinity), -Infinity);
12 assertEq(Math.fround(Infinity), Infinity);
13 assertEq(Math.fround(-0), -0);
14 assertEq(Math.fround(+0), +0);
16 // Polyfill function for Float32 conversion
17 var toFloat32 = (function() {
18 var f32 = new Float32Array(1);
19 function f(x) {
20 f32[0] = x;
21 return f32[0];
22 }
23 return f;
24 })();
26 // A test on a certain range of numbers, including big numbers, so that
27 // we get a loss in precision for some of them.
28 for (var i = 0; i < 64; ++i) {
29 var p = Math.pow(2, i) + 1;
30 assertEq(Math.fround(p), toFloat32(p));
31 assertEq(Math.fround(-p), toFloat32(-p));
32 }
34 /********************************************
35 /* Tests on maximal Float32 / Double values *
36 /*******************************************/
37 function maxValue(exponentWidth, significandWidth) {
38 var n = 0;
39 var maxExp = Math.pow(2, exponentWidth - 1) - 1;
40 for (var i = significandWidth; i >= 0; i--)
41 n += Math.pow(2, maxExp - i);
42 return n;
43 }
45 var DBL_MAX = maxValue(11, 52);
46 assertEq(DBL_MAX, Number.MAX_VALUE); // sanity check
48 // Finite as a double, too big for a float
49 assertEq(Math.fround(DBL_MAX), Infinity);
51 var FLT_MAX = maxValue(8, 23);
52 assertEq(Math.fround(FLT_MAX), FLT_MAX);
53 assertEq(Math.fround(FLT_MAX + Math.pow(2, Math.pow(2, 8 - 1) - 1 - 23 - 2)), FLT_MAX); // round-nearest rounds down to FLT_MAX
54 assertEq(Math.fround(FLT_MAX + Math.pow(2, Math.pow(2, 8 - 1) - 1 - 23 - 1)), Infinity); // no longer rounds down to FLT_MAX
56 /*********************************************************
57 /******* Tests on denormalizations and roundings *********
58 /********************************************************/
60 function minValue(exponentWidth, significandWidth) {
61 return Math.pow(2, -(Math.pow(2, exponentWidth - 1) - 2) - significandWidth);
62 }
64 var DBL_MIN = Math.pow(2, -1074);
65 assertEq(DBL_MIN, Number.MIN_VALUE); // sanity check
67 // Too small for a float
68 assertEq(Math.fround(DBL_MIN), 0);
70 var FLT_MIN = minValue(8, 23);
71 assertEq(Math.fround(FLT_MIN), FLT_MIN);
73 assertEq(Math.fround(FLT_MIN / 2), 0); // halfway, round-nearest rounds down to 0 (even)
74 assertEq(Math.fround(FLT_MIN / 2 + Math.pow(2, -202)), FLT_MIN); // first double > FLT_MIN / 2, rounds up to FLT_MIN
76 assertEq(Math.fround(-FLT_MIN), -FLT_MIN);
78 assertEq(Math.fround(-FLT_MIN / 2), -0); // halfway, round-nearest rounds up to -0 (even)
79 assertEq(Math.fround(-FLT_MIN / 2 - Math.pow(2, -202)), -FLT_MIN); // first double < -FLT_MIN / 2, rounds down to -FLT_MIN
81 reportCompare(0, 0, "ok");
