On Wed, 22 Mar 2023 12:46:33 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
>> 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:
>
> reviews
src/jdk.incubator.vector/share/classes/jdk/incubator/vector/Byte128Vector.java
line 868:
> 866: return (Byte128Vector) Byte128Vector.VSPECIES.dummyVector()
> 867: .vectorFactory(s.indices());
> 868: }
Move the implementation details to the super class?
src/jdk.incubator.vector/share/classes/jdk/incubator/vector/ByteMaxVector.java
line 862:
> 860: v.convertShape(VectorOperators.B2I, species, 3)
> 861: .reinterpretAsInts()
> 862: .intoArray(a, offset + species.length() * 3);
Can we add a method like `intoIntArray()` in `ByteVector` and move these common
code there? The same to other vector types.
src/jdk.incubator.vector/share/classes/jdk/incubator/vector/ByteMaxVector.java
line 919:
> 917: }
> 918: return false;
> 919: }
Same as `intoArray()`. Any possible that moving this function to `ByteVector`
and rename it to something like `shuffleIndicesInRange` ?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/13093#discussion_r1145769798
PR Review Comment: https://git.openjdk.org/jdk/pull/13093#discussion_r1145781044
PR Review Comment: https://git.openjdk.org/jdk/pull/13093#discussion_r1145782910
