Integrated: 8291550: RISC-V: jdk uses misaligned memory access when AvoidUnalignedAccess enabled

[Vladimir Kempik]

On Tue, 25 Apr 2023 15:37:30 GMT, Vladimir Kempik <vkempik at openjdk.org> wrote:

> Please review this attempt to remove misaligned loads and stores in risc-v specific part of jdk.
> 
> The patch has two main parts:
>  - opcodes loads/stores is now using put_native_uX/get_native_uX
>  - some code in template interp got changed to prevent misaligned loads
>  
> perf stat numbers for trp_lam ( misaligned loads) and trp_sam ( misaligned stores) before the patch: 
> 
>  169598      trp_lam                                          
>   13562      trp_sam  
> 
> 
> after the patch both numbers are zeroes.
> I can see template interpreter to be ~40 % faster on hifive unmatched ( 1 repetition of renaissance philosophers in -Xint mode), and the same performance ( before and after the patch) on thead rvb-ice ( which supports misaligned stores/loads in hw)
> 
> tier testing on hw is in progress

This pull request has now been integrated.

Changeset: 37093441
Author:    Vladimir Kempik <vkempik at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/37093441661c26f333aac00d16aea00c3341d314
Stats:     238 lines in 12 files changed: 150 ins; 0 del; 88 mod

8291550: RISC-V: jdk uses misaligned memory access when AvoidUnalignedAccess enabled

Co-authored-by: Xiaolin Zheng <xlinzheng at openjdk.org>
Co-authored-by: Feilong Jiang <fjiang at openjdk.org>
Reviewed-by: fjiang, fyang

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PR: https://git.openjdk.org/jdk/pull/13645