Integrated: 8340079: Modify rearrange/selectFrom Vector API methods to perform wrapIndexes instead of checkIndexes

[Sandhya Viswanathan]

On Mon, 19 Aug 2024 21:47:23 GMT, Sandhya Viswanathan <sviswanathan at openjdk.org> wrote:

> Currently the rearrange and selectFrom APIs check shuffle indices and throw IndexOutOfBoundsException if there is any exceptional source index in the shuffle. This causes the generated code to be less optimal. This PR modifies the rearrange/selectFrom Vector API methods to perform wrapIndexes instead of checkIndexes and performs optimizations to generate efficient code.
> 
> Summary of changes is as follows:
>  1) The rearrange/selectFrom methods do wrapIndexes instead of checkIndexes.
>  2) Intrinsic for wrapIndexes and selectFrom to generate efficient code
> 
> For the following source:
> 
> 
>     public void test() {
>         var index = ByteVector.fromArray(bspecies128, shuffles[1], 0);
>         for (int j = 0; j < bspecies128.loopBound(size); j += bspecies128.length()) {
>             var inpvect = ByteVector.fromArray(bspecies128, byteinp, j);
>             index.selectFrom(inpvect).intoArray(byteres, j);
>         }
>     }
> 
> 
> The code generated for inner main now looks as follows:
> ;; B24: #      out( B24 B25 ) <- in( B23 B24 ) Loop( B24-B24 inner main of N173 strip mined) Freq: 4160.96
>   0x00007f40d02274d0:   movslq %ebx,%r13
>   0x00007f40d02274d3:   vmovdqu 0x10(%rsi,%r13,1),%xmm1
>   0x00007f40d02274da:   vpshufb %xmm2,%xmm1,%xmm1
>   0x00007f40d02274df:   vmovdqu %xmm1,0x10(%rax,%r13,1)
>   0x00007f40d02274e6:   vmovdqu 0x20(%rsi,%r13,1),%xmm1
>   0x00007f40d02274ed:   vpshufb %xmm2,%xmm1,%xmm1
>   0x00007f40d02274f2:   vmovdqu %xmm1,0x20(%rax,%r13,1)
>   0x00007f40d02274f9:   vmovdqu 0x30(%rsi,%r13,1),%xmm1
>   0x00007f40d0227500:   vpshufb %xmm2,%xmm1,%xmm1
>   0x00007f40d0227505:   vmovdqu %xmm1,0x30(%rax,%r13,1)
>   0x00007f40d022750c:   vmovdqu 0x40(%rsi,%r13,1),%xmm1
>   0x00007f40d0227513:   vpshufb %xmm2,%xmm1,%xmm1
>   0x00007f40d0227518:   vmovdqu %xmm1,0x40(%rax,%r13,1)
>   0x00007f40d022751f:   add    $0x40,%ebx
>   0x00007f40d0227522:   cmp    %r8d,%ebx
>   0x00007f40d0227525:   jl     0x00007f40d02274d0
> 
> Best Regards,
> Sandhya

This pull request has now been integrated.

Changeset: 83dcb02d
Author:    Sandhya Viswanathan <sviswanathan at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/83dcb02d776448aa04f3f41df489bd4355443a4d
Stats:     697 lines in 47 files changed: 549 ins; 34 del; 114 mod

8340079: Modify rearrange/selectFrom Vector API methods to perform wrapIndexes instead of checkIndexes

Reviewed-by: jbhateja, psandoz

-------------

PR: https://git.openjdk.org/jdk/pull/20634