RFR: 8316933: RISC-V: compiler/vectorapi/VectorCastShape128Test.java fails when using RVV [v2]

[Dingli Zhang]

On Tue, 26 Sep 2023 09:36:44 GMT, Gui Cao <gcao at openjdk.org> wrote:

>> Hi, we are experiencing test failures in test/hotspot/jtreg/compiler/vectorapi/VectorCastShape128Test.java using latest qemu, see jbs issue for exception information.
>> 
>> 
>> zifeihan at plct-c8:~/qemu-master-riscv64/bin$ ./qemu-riscv64 -version
>> qemu-riscv64 version 8.1.50
>> Copyright (c) 2003-2023 Fabrice Bellard and the QEMU Project developers
>> 
>> By the way, using a lower version of qemu (qemu-riscv64 version 7.0.91) no such problems were encountered. we infer that version 8.1.50 of qemu adds better checks.
>> 
>> 
>> /home/zifeihan/jtreg/bin/jtreg -J-Djavatest.maxOutputSize=500000 -Djdk.lang.Process.launchMechanism=vfork -v:default -concurrency:48 -timeout:50 -javaoption:-XX:+UnlockExperimentalVMOptions -javaoption:-XX:+UseRVV -jdk:/home/zifeihan/jdk/build/linux-riscv64-server-fastdebug/jdk -compilejdk:/home/zifeihan/jdk-rvv/build/linux-x86_64-server-release/jdk /home/zifeihan/jdk/test/hotspot/jtreg/compiler/vectorapi/VectorCastShape128Test.java
>> 
>> 1. SEW setting is not accurate
>> 
>> https://github.com/openjdk/jdk/blob/e2e8e8e210ea9a7a9d901a1da729551714015d04/src/hotspot/cpu/riscv/c2_MacroAssembler_riscv.cpp#L2195-L2207
>> 
>> The reason for the error reported for the vcvtFtoX_narrow node is because the vmfeq_vv directive is used here, but when the macro is called, the vsetvli type is set to T_SHORT, not T_FLOAT, so an exception occurs here. 
>> 
>> For vcvtFtoL, vcvtDtoX_narrow nodes, there was also the problem of inaccurate setting of both SEW, which is also changed here.
>> 
>> 2. Register usage constraints
>> For the vcvtStoX_fp_extend node, the operands of the vfwcvt_f_f_v instruction inside, the same register cannot be used here[1], so that has also been modified.
>> 
>> [1] https://github.com/riscv/riscv-v-spec/blob/v1.0/v-spec.adoc#sec-vec-operands
>> 
>> ### Testing:
>> qemu 8.1.50 with UseRVV:
>> - [x] Tier1 tests (release)
>> - [x] Tier2 tests (release)
>> - [x] Tier3 tests (release)
>> - [x] test/jdk/jdk/incubator/vector (fastdebug)
>
> Gui Cao has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Format code

LGTM, thanks!

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Marked as reviewed by dzhang (Author).

PR Review: https://git.openjdk.org/jdk/pull/15911#pullrequestreview-1644416826