mirror of
https://github.com/fluencelabs/assemblyscript
synced 2025-04-25 07:02:13 +00:00
83 lines
2.7 KiB
JavaScript
83 lines
2.7 KiB
JavaScript
/*
|
|
MIT License
|
|
|
|
Copyright (c) 2017 Mauro Bringolf
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
of this software and associated documentation files (the "Software"), to deal
|
|
in the Software without restriction, including without limitation the rights
|
|
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
copies of the Software, and to permit persons to whom the Software is
|
|
furnished to do so, subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in all
|
|
copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
SOFTWARE.
|
|
*/
|
|
// see: https://github.com/maurobringolf/webassembly-floating-point-hex-parser
|
|
function parse(input) {
|
|
input = input.toUpperCase();
|
|
const splitIndex = input.indexOf('P');
|
|
let mantissa, exponent;
|
|
|
|
if (splitIndex !== -1) {
|
|
mantissa = input.substring(0, splitIndex);
|
|
exponent = parseInt(input.substring(splitIndex + 1));
|
|
} else {
|
|
mantissa = input;
|
|
exponent = 0;
|
|
}
|
|
|
|
const dotIndex = mantissa.indexOf('.');
|
|
|
|
if (dotIndex !== -1) {
|
|
let integerPart = parseInt(mantissa.substring(0,dotIndex), 16);
|
|
let sign = Math.sign(integerPart);
|
|
integerPart = sign * integerPart;
|
|
const fractionLength = mantissa.length - dotIndex - 1;
|
|
const fractionalPart = parseInt(mantissa.substring(dotIndex + 1), 16);
|
|
const fraction = fractionLength > 0 ? fractionalPart / Math.pow(16, fractionLength) : 0;
|
|
if (sign === 0) {
|
|
if (fraction === 0) {
|
|
mantissa = sign;
|
|
} else {
|
|
if (Object.is(sign, -0)) {
|
|
mantissa = - fraction;
|
|
} else {
|
|
mantissa = fraction;
|
|
}
|
|
}
|
|
} else {
|
|
mantissa = sign * (integerPart + fraction);
|
|
}
|
|
} else {
|
|
mantissa = parseInt(mantissa, 16);
|
|
}
|
|
|
|
return mantissa * (splitIndex !== -1 ? Math.pow(2, exponent) : 1);
|
|
}
|
|
|
|
if (typeof process !== "undefined") {
|
|
if (process.argv.length < 3) {
|
|
console.error("Usage: hexfloat 0x1p1023");
|
|
process.exit(1);
|
|
}
|
|
|
|
var output = parse(process.argv[2]);
|
|
var double = output.toPrecision(18); // 17
|
|
var single = output.toPrecision(10); // 9
|
|
|
|
console.log("<f64>" + double);
|
|
console.log("<f32>" + single);
|
|
|
|
if (!(parseFloat(double) === output)) throw Error("double precision error");
|
|
if (!(Math.fround(parseFloat(single)) === Math.fround(output))) throw Error("single precision error");
|
|
}
|