在asm.js中转换int [ish]和double [ish]

Question

如果我需要,比如在asm.js模块中找到数字的整数部分和小数部分,我该怎么办？没有标准运算符在intish和doubleish类型之间进行转换; 甚至Math.floor返回一个double,其结果也不能强制转换为int.

var floor = stdlib.Math.floor;

function(n) {
    n = +n;
    var a = 0;
    a = floor(n)|0; // fails: "Operands to bitwise ops must be intish"
    var b = 0.0;
    b = +(n-a); // would fail if compiler got to here
    return;
}

Answer 1

Vyacheslav Egorov(推特:@mraleph)说:~~用来胁迫int.特殊验证案例:http://asmjs.org/spec/latest/#unaryexpression

a = ~~floor(n); // success!