RFR: 8307609: RISC-V: Added support for Extract, Compress, Expand and other nodes for Vector API [v8]

[Fei Yang]

On Wed, 17 May 2023 08:59:55 GMT, Dingli Zhang <dzhang at openjdk.org> wrote:

>> Hi all,
>> 
>> We have added support for Extract, Compress, Expand and other nodes for Vector
>> API. It was implemented by referring to RVV v1.0 [1]. Please take a look and
>> have some reviews. Thanks a lot.
>> 
>> In this PR, we will support these new nodes:
>> 
>> CompressM/CompressV/ExpandV
>> LoadVectorGather/StoreVectorScatter/LoadVectorGatherMasked/StoreVectorScatterMasked
>> Extract
>> VectorLongToMask/VectorMaskToLong
>> PopulateIndex
>> VectorLongToMask/VectorMaskToLong
>> VectorMaskTrueCount/VectorMaskFirstTrue
>> VectorInsert
>> 
>> 
>> At the same time, we refactored methods such as
>> `match_rule_supported_vector_mask`. All implemented vector nodes support mask
>> operations by default now, so we also added mask nodes for all implemented
>> nodes. 
>> 
>> By the way, we will implement the VectorTest node in the next PR.
>> 
>> We can use the tests under `test/jdk/jdk/incubator/vector` to print the 
>> compilation log for most of the new nodes. And we can use the following 
>> command to print the compilation log of a jtreg test case:
>> 
>> 
>> $ jtreg \
>> -v:default \
>> -concurrency:16 -timeout:50 \
>> -javaoption:-XX:+UnlockExperimentalVMOptions \
>> -javaoption:-XX:+UseRVV \
>> -javaoption:-XX:+PrintOptoAssembly \
>> -javaoption:-XX:LogFile=log_name.log \
>> -jdk:build/linux-riscv64-server-fastdebug/jdk \
>> -compilejdk:build/linux-x86_64-server-release/images/jdk \
>> <test-case>
>> 
>> 
>> 
>> 
>> ### CompressM/CompressV/ExpandV
>> 
>> There is no inverse vdecompress provided in RVV, as this operation can be
>> readily synthesized using iota and a masked vrgather in `ExpandV`.
>> 
>> We can use `test/jdk/jdk/incubator/vector/Float256VectorTests.java` to emit
>> these nodes and the compilation log is as follows:
>> 
>> 
>> ## CompressM
>> 2aa     addi  R29, R10, #16	# ptr, #@addP_reg_imm
>> 2ae     mcompress V0, V30	# KILL R30
>> 2c2     vstoremask V2, V0
>> 2ce     storeV [R7], V2	# vector (rvv)
>> 2d6     bgeu  R29, R28, B47	#@cmpP_branch  P=0.000100 C=-1.000000
>> 
>> ## CompressV
>> 0ee     addi  R29, R10, #16	# ptr, #@addP_reg_imm
>> 0f2     vcompress V1, V2, V0
>> 0fe     storeV [R7], V1	# vector (rvv)
>> 106     bgeu  R29, R28, B10	#@cmpP_branch  P=0.000100 C=-1.000000
>> 
>> ## ExpandV
>> 0ee     addi  R29, R10, #16	# ptr, #@addP_reg_imm
>> 0f2     vexpand V3, V2, V0
>> 102     storeV [R7], V3	# vector (rvv)
>> 10a     bgeu  R29, R28, B10	#@cmpP_branch  P=0.000100 C=-1.000000
>> 
>> 
>> 
>> 
>> ### LoadVectorGather/StoreVectorScatter/LoadVectorGatherMasked/StoreVectorScatterMasked
>> 
>> We use the vs...
>
> Dingli Zhang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 18 commits:
> 
>  - Add some comments
>  - Merge remote-tracking branch 'upstream/master' into JDK-8307609
>  - Adjust some params order in c2_MacroAssembler_riscv
>  - Adjust some function in c2_MacroAssembler_riscv
>  - Remove trailing whitespace
>  - Fix minmax_fp_masked_v
>  - Change some iRegI to iRegIorL2I and small refactoring of minmax_fp_masked_v
>  - Remove debug warning
>  - Merge master and resolve conflict
>  - Optimize call point of vfclass and adjust the parameters of c2 instruct
>  - ... and 8 more: https://git.openjdk.org/jdk/compare/2f1c6548...1fc880e3

src/hotspot/cpu/riscv/riscv_v.ad line 4263:

> 4261:     __ vsetvli_helper(bt, Matcher::vector_length(this, $src));
> 4262:     __ vmsbf_m(as_VectorRegister($tmp$$reg), as_VectorRegister($src$$reg), Assembler::v0_t);
> 4263:     __ vcpop_m($dst$$Register, as_VectorRegister($tmp$$reg));

Shouldn't this be: `__ vcpop_m($dst$$Register, as_VectorRegister($tmp$$reg), Assembler::v0_t);`?
And do we missed `VectorMaskLastTrue`?

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

PR Review Comment: https://git.openjdk.org/jdk/pull/13862#discussion_r1196468562