/**

* @fileoverview Various math utility.

* @license Apache-2.0

*/

/** Tests if `x` is a power of two. */

export function isPowerOf2(x: i32): bool {

return x != 0 && (x & (x - 1)) == 0;

}

export function accuratePow64(x: f64, y: f64): f64 {

if (!ASC_TARGET) { // ASC_TARGET == JS

// Engines like V8, WebKit and SpiderMonkey uses powi fast path if exponent is integer

// This speculative optimization leads to loose precisions like 10 ** 208 != 1e208

// or/and 10 ** -5 != 1e-5 anymore. For avoid this behaviour we are forcing exponent

// to fractional form and compensate this afterwards.

if (isFinite(y) && Math.abs(y) >= 2 && Math.trunc(y) == y) {

if (y < 0) {

return Math.pow(x, y + 0.5) / Math.pow(x, 0.5);

} else {

return Math.pow(x, y - 0.5) * Math.pow(x, 0.5);

}

}

}

return Math.pow(x, y);

}