On Tue, 7 Mar 2023 18:23:42 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
> `Vector::slice` is a method at the top-level class of the Vector API that
> concatenates the 2 inputs into an intermediate composite and extracts a
> window equal to the size of the inputs into the result. It is used in vector
> conversion methods where the part number is not 0 to slice the parts to the
> correct positions. Slicing is also used in text processing such as utf8 and
> utf16 validation. x86 starting from SSSE3 has `palignr` which does vector
> slicing very efficiently. As a result, I think it is beneficial to add a C2
> node for this operation as well as intrinsify `Vector::slice` method.
>
> A slice is currently implemented as
> `v2.rearrange(iota).blend(v1.rearrange(iota), blendMask)` which requires
> preparation of the index vector and the blending mask. Even with the
> preparations being hoisted out of the loops, microbenchmarks show improvement
> using the slice instrinsics. Some have tremendous increases in throughput due
> to the limitation that a mask of length 2 cannot currently be intrinsified,
> leading to falling back to the Java implementations.
>
> Please take a look and have some reviews. Thank you very much.
src/jdk.incubator.vector/share/classes/jdk/incubator/vector/ByteVector.java
line 2289:
> 2287: getClass(), byte.class, length(),
> 2288: this, that, origin,
> 2289: new VectorSliceOp<ByteVector>() {
Change from inner class to lambda expression?
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PR: https://git.openjdk.org/jdk/pull/12909
