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- /* eslint no-bitwise: "off" */
- // Credit: https://github.com/paulmillr/es6-shim/
- "use strict";
- var pow = Math.pow;
- module.exports = function (bytes, ebits, fbits) {
- // Bytes to bits
- var bits = [], i, j, bit, str, bias, sign, e, fraction;
- for (i = bytes.length; i; i -= 1) {
- bit = bytes[i - 1];
- for (j = 8; j; j -= 1) {
- bits.push(bit % 2 ? 1 : 0);
- bit >>= 1;
- }
- }
- bits.reverse();
- str = bits.join("");
- // Unpack sign, exponent, fraction
- bias = (1 << (ebits - 1)) - 1;
- sign = parseInt(str.substring(0, 1), 2) ? -1 : 1;
- e = parseInt(str.substring(1, 1 + ebits), 2);
- fraction = parseInt(str.substring(1 + ebits), 2);
- // Produce number
- if (e === (1 << ebits) - 1) return fraction === 0 ? sign * Infinity : NaN;
- if (e > 0) return sign * pow(2, e - bias) * (1 + fraction / pow(2, fbits));
- if (fraction !== 0) return sign * pow(2, -(bias - 1)) * (fraction / pow(2, fbits));
- return sign < 0 ? -0 : 0;
- };
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