On Wed, 18 Sep 2024 17:00:30 GMT, Sandhya Viswanathan
<sviswanat...@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
>
> Sandhya Viswanathan has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Change method name
src/hotspot/share/opto/vectorIntrinsics.cpp line 772:
> 770:
> 771: if (elem_klass == nullptr || shuffle_klass == nullptr ||
> shuffle->is_top() || vlen == nullptr) {
> 772: return false; // dead code
Why dead code in comment ? this is a failed intrinsification condition.
src/hotspot/share/opto/vectorIntrinsics.cpp line 776:
> 774: if (!vlen->is_con() || shuffle_klass->const_oop() == nullptr) {
> 775: return false; // not enough info for intrinsification
> 776: }
Why don't you club it with above conditions to be consistent with other inline
expanders ?
src/hotspot/share/opto/vectorIntrinsics.cpp line 790:
> 788: // Shuffles use byte array based backing storage
> 789: BasicType shuffle_bt = T_BYTE;
> 790:
No need a of new line b/w 789 and 791
src/hotspot/share/opto/vectorIntrinsics.cpp line 793:
> 791: if (!arch_supports_vector(Op_AndV, num_elem, shuffle_bt,
> VecMaskNotUsed) ||
> 792: !arch_supports_vector(Op_Replicate, num_elem, shuffle_bt,
> VecMaskNotUsed)) {
> 793: return false;
You should emit proper intrinsification failure message here.
src/hotspot/share/opto/vectorIntrinsics.cpp line 805:
> 803: const TypeVect* vt = TypeVect::make(shuffle_bt, num_elem);
> 804: const Type* shuffle_type_bt = Type::get_const_basic_type(shuffle_bt);
> 805:
No need of a blank line here.
src/hotspot/share/opto/vectorIntrinsics.cpp line 808:
> 806: Node* mod_mask = gvn().makecon(TypeInt::make(num_elem-1));
> 807: Node* bcast_mod_mask =
> gvn().transform(VectorNode::scalar2vector(mod_mask, num_elem,
> shuffle_type_bt));
> 808:
Remove redundant new line.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766272449
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766273205
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766273880
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766274718
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766275107
PR Review Comment: https://git.openjdk.org/jdk/pull/20634#discussion_r1766275345
