RFR: 8304450: [vectorapi] Refactor VectorShuffle implementation [v7]

[Quan Anh Mai]

> Hi,
> 
> This patch reimplements `VectorShuffle` implementations to be a vector of the bit type. Currently, VectorShuffle is stored as a byte array, and would be expanded upon usage. This poses several drawbacks:
> 
> 1. Inefficient conversions between a shuffle and its corresponding vector. This hinders the performance when the shuffle indices are not constant and are loaded or computed dynamically.
> 2. Redundant expansions in `rearrange` operations. On all platforms, it seems that a shuffle index vector is always expanded to the correct type before executing the `rearrange` operations.
> 3. Some redundant intrinsics are needed to support this handling as well as special considerations in the C2 compiler.
> 4. Range checks are performed using `VectorShuffle::toVector`, which is inefficient for FP types since both FP conversions and FP comparisons are more expensive than the integral ones.
> 
> Upon these changes, a `rearrange` can emit more efficient code:
> 
>     var species = IntVector.SPECIES_128;
>     var v1 = IntVector.fromArray(species, SRC1, 0);
>     var v2 = IntVector.fromArray(species, SRC2, 0);
>     v1.rearrange(v2.toShuffle()).intoArray(DST, 0);
> 
>     Before:
>     movabs $0x751589fa8,%r10            ;   {oop([I{0x0000000751589fa8})}
>     vmovdqu 0x10(%r10),%xmm2
>     movabs $0x7515a0d08,%r10            ;   {oop([I{0x00000007515a0d08})}
>     vmovdqu 0x10(%r10),%xmm1
>     movabs $0x75158afb8,%r10            ;   {oop([I{0x000000075158afb8})}
>     vmovdqu 0x10(%r10),%xmm0
>     vpand  -0xddc12(%rip),%xmm0,%xmm0        # Stub::vector_int_to_byte_mask
>                                                             ;   {external_word}
>     vpackusdw %xmm0,%xmm0,%xmm0
>     vpackuswb %xmm0,%xmm0,%xmm0
>     vpmovsxbd %xmm0,%xmm3
>     vpcmpgtd %xmm3,%xmm1,%xmm3
>     vtestps %xmm3,%xmm3
>     jne    0x00007fc2acb4e0d8
>     vpmovzxbd %xmm0,%xmm0
>     vpermd %ymm2,%ymm0,%ymm0
>     movabs $0x751588f98,%r10            ;   {oop([I{0x0000000751588f98})}
>     vmovdqu %xmm0,0x10(%r10)
> 
>     After:
>     movabs $0x751589c78,%r10            ;   {oop([I{0x0000000751589c78})}
>     vmovdqu 0x10(%r10),%xmm1
>     movabs $0x75158ac88,%r10            ;   {oop([I{0x000000075158ac88})}
>     vmovdqu 0x10(%r10),%xmm2
>     vpxor  %xmm0,%xmm0,%xmm0
>     vpcmpgtd %xmm2,%xmm0,%xmm3
>     vtestps %xmm3,%xmm3
>     jne    0x00007fa818b27cb1
>     vpermd %ymm1,%ymm2,%ymm0
>     movabs $0x751588c68,%r10            ;   {oop([I{0x0000000751588c68})}
>     vmovdqu %xmm0,0x10(%r10)
>     
> Please take a look and leave reviews. Thanks a lot.

Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:

  special case iotaShuffle

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13093/files
  - new: https://git.openjdk.org/jdk/pull/13093/files/97c8fabf..079a6b5f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13093&range=06
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13093&range=05-06

  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/13093.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13093/head:pull/13093

PR: https://git.openjdk.org/jdk/pull/13093