On Tue, 19 Apr 2022 17:40:07 GMT, Paul Sandoz <psan...@openjdk.org> wrote:
> Not yet talked with John, but i investigated further. The implementation of > the `LSHR` operation is behaving as intended, but is under specified with > regards to `byte` and `short` as you noted in #8291. > > This is a subtle area, but i am wondering if the user really means to use > arithmetic shift in this case? Since is not the following true for all values > of `e` and `c`, where `e` is a `byte` and `c` is the right shift count > ranging from 0 to 7: > > ``` > (byte) (e >>> c) == (byte) (e >> c) > ``` > > ? > > Then the user can use `VectorOperators.ASHR`. Yes, in theory, the user can use `ASHR`. But people have to be very careful about when to use `AHSR` and when to use `LSHR`, which is really inconvenient and easy to make a mistake. And not all the people are smart enough to know this skill for bytes/shorts. So to make it to be programmed more easily and also reduce the possibility to make mistakes, a new operator for scalar `>>>` would be helpful when vectorizing with Vector API. Thanks. ------------- PR: https://git.openjdk.java.net/jdk/pull/8276
