On Fri, 2 May 2025 17:49:54 GMT, Raffaello Giulietti <rgiulie...@openjdk.org> wrote:
> Yes, I'm familiar with both this Java code and the intrinsic code. > > Compare this with the much simpler proposed code. The checked multiplication > `unsignedMultiplyExact` apparently performs two 64x64->64 multiplications, > but on some architectures it might end up in a single 64x64->128 > multiplication and one check. So the proposed code performs 6 such > multiplications if the method returns + 5 ordinary multiplications in the > worst case. > > As a general rule, the simpler the code, the better the outcome of the > optimizing compiler. > > Again, to me there's no point in failing fast at the expense of the > successful case. Yes; we can always try to make simpler code faster if the need or interest arises. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/25003#discussion_r2074441059
