On Fri, 2 May 2025 16:53:39 GMT, Raffaello Giulietti <rgiulie...@openjdk.org>
wrote:
> As for the `bitLength` check, the product might overflow. Further,
> `bitLength` might not be that cheap.
The current implementations of `bitLength()` calls `numberOfLeadingZeros`,
which are:
public static int numberOfLeadingZeros(long i) {
int x = (int)(i >>> 32);
return x == 0 ? 32 + Integer.numberOfLeadingZeros((int)i)
: Integer.numberOfLeadingZeros(x);
}
public static int numberOfLeadingZeros(int i) {
// HD, Count leading 0's
if (i <= 0)
return i == 0 ? 32 : 0;
int n = 31;
if (i >= 1 << 16) { n -= 16; i >>>= 16; }
if (i >= 1 << 8) { n -= 8; i >>>= 8; }
if (i >= 1 << 4) { n -= 4; i >>>= 4; }
if (i >= 1 << 2) { n -= 2; i >>>= 2; }
return n - (i >>> 1);
}
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/25003#discussion_r2071934498
