38 lines
799 B
JavaScript
38 lines
799 B
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", {
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value: true
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});
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exports.fromBitmap = fromBitmap;
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exports.hashFragment = hashFragment;
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exports.popcount = popcount;
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exports.toBitmap = toBitmap;
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var _config = require("./config.js");
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/**
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* Hamming weight.
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*
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* Taken from: http://jsperf.com/hamming-weight
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*
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* @internal
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*/
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function popcount(x) {
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x -= x >> 1 & 0x55555555;
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x = (x & 0x33333333) + (x >> 2 & 0x33333333);
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x = x + (x >> 4) & 0x0f0f0f0f;
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x += x >> 8;
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x += x >> 16;
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return x & 0x7f;
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}
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/** @internal */
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function hashFragment(shift, h) {
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return h >>> shift & _config.MASK;
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}
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/** @internal */
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function toBitmap(x) {
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return 1 << x;
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}
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/** @internal */
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function fromBitmap(bitmap, bit) {
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return popcount(bitmap & bit - 1);
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}
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//# sourceMappingURL=bitwise.js.map
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