fn asinh64(x: f64) f64 x: f6456
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81fn asinh64(x: f64) f64 {
const u = @as(u64, @bitCast(x));
const e = (u >> 52) & 0x7FF;
const s = u >> 63;
var rx = @as(f64, @bitCast(u & (maxInt(u64) >> 1))); // |x|
// |x| >= 0x1p26 or inf or nan
if (e >= 0x3FF + 26) {
rx = @log(rx) + 0.693147180559945309417232121458176568;
}
// |x| >= 2
else if (e >= 0x3FF + 1) {
rx = @log(2 * rx + 1 / (@sqrt(rx * rx + 1) + rx));
}
// |x| >= 0x1p-12, up to 1.6ulp error
else if (e >= 0x3FF - 26) {
rx = math.log1p(rx + rx * rx / (@sqrt(rx * rx + 1) + 1));
}
// |x| < 0x1p-12, inexact if x != 0
else {
mem.doNotOptimizeAway(rx + 0x1.0p120);
}
return if (s != 0) -rx else rx;
}