diff options
Diffstat (limited to 'node_modules/es5-ext/math/_unpack-ieee754.js')
-rw-r--r-- | node_modules/es5-ext/math/_unpack-ieee754.js | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/node_modules/es5-ext/math/_unpack-ieee754.js b/node_modules/es5-ext/math/_unpack-ieee754.js new file mode 100644 index 000000000..83fa9475e --- /dev/null +++ b/node_modules/es5-ext/math/_unpack-ieee754.js @@ -0,0 +1,33 @@ +/* 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; +}; |