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uint32 - npm Package Compare versions
Comparing version 0.1.1 to 0.1.2
| { | ||
| "name": "uint32", | ||
| "version": "0.1.1", | ||
| "version": "0.1.2", | ||
| "description": "a javascript library for dealing with (bitwise) uint32 operations", | ||
@@ -8,3 +8,3 @@ "homepage": "https://www.github.com/fxa/uint32.js", | ||
| "scripts": { | ||
| "test": "jshint uint32.js test_uint32.js && mocha test_uint32", | ||
| "test": "jshint uint32.js test_uint32.js && mocha --reporter spec test_uint32", | ||
| "hint": "jshint uint32.js test_uint32.js" | ||
@@ -11,0 +11,0 @@ }, |
@@ -82,13 +82,16 @@ uint32 | ||
| uint32.rotateLeft(0x80000000, 1); // 0x00000001 | ||
| uint32.rotateLeft(0x00000001, 1); // 0x80000000 | ||
| uint32.rotateRight(0x00000001, 1); // 0x80000000 | ||
| // Logical Gates | ||
| // Logical Gates | ||
| uint32.choose(0x01010202, 0x00010001, 0x01000100); // 0x00010100 | ||
| // function majority (x, y, z) | ||
| uint32.majority (0x01, 0x00, 0x01); // 0x01 | ||
| // Arithmetic | ||
| uint32.addMod32(0x80000001, 0x80000001); // 2 | ||
| uint32.log2(0xffffffff); // 31 | ||
| uint32.multLow(0xffffffff, 0xffffffff); // 1 | ||
| uint32.multHigh(0xffffffff, 0xffffffff); // 0xfffffffe | ||
| // That's all! Detailed specifications are in the tests! | ||
| // That's all! | ||
| // Detailed specifications are in the tests! | ||
| ``` | ||
@@ -95,0 +98,0 @@ |
@@ -184,3 +184,24 @@ /* global describe, it, require, window */ | ||
| }); | ||
| describe('majority()', function () {}); | ||
| describe('majority()', function () { | ||
| it('should return 0, if all parameters are 0', function () { | ||
| expect(uint32.majority(0, 0, 0)).to.be(0); | ||
| }); | ||
| it('should return 0, if all but one parameters are 0', function () { | ||
| expect(uint32.majority(0xffffffff, 0, 0)).to.be(0); | ||
| expect(uint32.majority(0, 0xffffffff, 0)).to.be(0); | ||
| expect(uint32.majority(0, 0, 0xffffffff)).to.be(0); | ||
| }); | ||
| it('should return 0xffffffff, if two parameters are 0xffffffff', function () { | ||
| expect(uint32.majority(0xffffffff, 0xffffffff, 0)).to.be(0xffffffff); | ||
| expect(uint32.majority(0xffffffff, 0, 0xffffffff)).to.be(0xffffffff); | ||
| expect(uint32.majority(0, 0xffffffff, 0xffffffff)).to.be(0xffffffff); | ||
| }); | ||
| it('should return 0xffffffff, if all parameters are 0xffffffff', function () { | ||
| expect(uint32.majority(0xffffffff, 0xffffffff, 0xffffffff)).to.be(0xffffffff); | ||
| }); | ||
| it('should work bitwise', function () { | ||
| // all above tests bitwise | ||
| expect(uint32.majority(parseInt('01001101', 2), parseInt('00101011', 2), parseInt('00010111', 2))).to.be(parseInt('00001111', 2)); | ||
| }); | ||
| }); | ||
| }); | ||
@@ -206,3 +227,53 @@ | ||
| }); | ||
| describe('log2', function () { | ||
| it('should work for 0', function () { | ||
| expect(uint32.log2(0)).to.be(-Infinity); | ||
| }); | ||
| it('should work for 1', function () { | ||
| expect(uint32.log2(1)).to.be(0); | ||
| }); | ||
| it('should work for 2', function () { | ||
| expect(uint32.log2(2)).to.be(1); | ||
| }); | ||
| it('should work for values between 2 and 2^31', function () { | ||
| for (var exp = 2; exp < 32; exp += 1) { | ||
| var pow = Math.pow(2, exp); | ||
| expect(uint32.log2(pow - 1)).to.be(exp - 1); | ||
| expect(uint32.log2(pow)).to.be(exp); | ||
| } | ||
| }); | ||
| it('should work for 2^32-1', function () { | ||
| expect(uint32.log2(0xffffffff)).to.be(31); | ||
| }); | ||
| }); | ||
| describe('multLow', function () { | ||
| it('should work, if the product is smaller than 2^52', function () { | ||
| expect(uint32.multLow(0x04000000, 0x03ffffff)).to.be(0xfc000000); | ||
| }); | ||
| it('should work, if the product is 2^52', function () { | ||
| expect(uint32.multLow(0x04000000, 0x04000000)).to.be(0); | ||
| }); | ||
| it('should work, if the product is greater than 2^52', function () { | ||
| expect(uint32.multLow(0xff030201, 0xff030201)).to.be(0x0a0a0401); | ||
| expect(uint32.multLow(0xffffffff, 0xffffffff)).to.be(0x00000001); | ||
| }); | ||
| }); | ||
| describe('multHigh', function () { | ||
| it('should return 0, if the product is less than 2^32', function () { | ||
| expect(uint32.multHigh(0xffff, 0xffff)).to.be(0); | ||
| }); | ||
| it('should work, if the product is smaller than 2^52', function () { | ||
| expect(uint32.multHigh(0x04000000, 0x03ffffff)).to.be(0xfffff); | ||
| }); | ||
| it('should work, if the product is 2^52', function () { | ||
| expect(uint32.multHigh(0x04000000, 0x04000000)).to.be(0x00100000); | ||
| }); | ||
| it('should work, if the product is greater than 2^52', function () { | ||
| expect(uint32.multHigh(0xffffffff, 0xffffffff)).to.be(0xfffffffe); | ||
| expect(uint32.multHigh(0xff030201, 0xff030201)).to.be(0xfe06fe07); | ||
| }); | ||
| }); | ||
| }); | ||
| })(); |
@@ -9,2 +9,5 @@ /* jshint bitwise: false */ | ||
| var POW_2_32 = 0x0100000000; | ||
| var POW_2_52 = 0x10000000000000; | ||
| // | ||
@@ -68,3 +71,3 @@ // Creating and Extracting | ||
| exporter.highPart = function (number) { | ||
| return exporter.toUint32(number / 0x0100000000); | ||
| return exporter.toUint32(number / POW_2_32); | ||
| }; | ||
@@ -189,4 +192,63 @@ | ||
| /** | ||
| * Returns the log base 2 of the given value. That is the number of the highest set bit. | ||
| * @param uint32val | ||
| * @returns {Number} the logarithm base 2, an integer between 0 and 31 | ||
| */ | ||
| exporter.log2 = function (uint32val) { | ||
| return Math.floor(Math.log(uint32val) / Math.LN2); | ||
| }; | ||
| /* | ||
| // this implementation does the same, looks much funnier, but takes 2 times longer (according to jsperf) ... | ||
| var log2_u = new Uint32Array(2); | ||
| var log2_d = new Float64Array(log2_u.buffer); | ||
| exporter.log2 = function (uint32val) { | ||
| // Ported from http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogIEEE64Float to javascript | ||
| // (public domain) | ||
| if (uint32val === 0) { | ||
| return -Infinity; | ||
| } | ||
| // fill in the low part | ||
| log2_u[0] = uint32val; | ||
| // set the mantissa to 2^52 | ||
| log2_u[1] = 0x43300000; | ||
| // subtract 2^52 | ||
| log2_d[0] -= 0x10000000000000; | ||
| return (log2_u[1] >>> 20) - 0x3FF; | ||
| }; | ||
| */ | ||
| /** | ||
| * Returns the "low" part of the multiplication. | ||
| * @param {Number} factor1 an uint32 | ||
| * @param {Number} factor2 an uint32 | ||
| * @returns {Number} the low part of the product, that is factor1 * factor2 modulus 2^32 | ||
| */ | ||
| exporter.multLow = function (factor1, factor2) { | ||
| // We could test with log2(factor1) + log2(factor2) < 52, | ||
| // but it is easier to check the product than to check the number of bits of both | ||
| var prod = factor1 * factor2; | ||
| if (prod <= POW_2_52) { | ||
| return prod >>> 0; | ||
| } | ||
| // a*b mod x can be divided to (a1*b) mod x + (a2*b) mod x with a1+a2=a | ||
| // so lets make 2 multiplications with 16 and 32 bits | ||
| return ((((factor1 & 0xffff0000) * factor2) >>> 0) + (((factor1 & 0x0000ffff) * factor2) >>> 0)) >>> 0; | ||
| }; | ||
| /** | ||
| * Returns the "high" part of the multiplication. | ||
| * @param {Number} factor1 an uint32 | ||
| * @param {Number} factor2 an uint32 | ||
| * @returns {Number} the high part of the product, that is factor1 * factor2 divided 2^32 without fraction | ||
| */ | ||
| exporter.multHigh = function (factor1, factor2) { | ||
| var prod = factor1 * factor2; | ||
| // the top 52 are ok, so the top 32 bits, too | ||
| return exporter.highPart(prod); | ||
| }; | ||
| }) ((typeof module !== 'undefined') ? module.exports = {} : window.uint32 = {}); | ||
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Improved metrics
- Total package byte prevSize
- increased by31.53%
26699
- Lines of code
- increased by35.9%
477
- Number of lines in readme file
- increased by2.94%
105
No dependency changes