https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128408

--- Comment #1 from Hongtao Liu <liuhongt at gcc dot gnu.org> ---
Could it be related to code alignment? 

------------cut from [1] ---------------
Note for lbm on AMD Zen 5 with GCC 16
We discovered 782.lbm_r may have 2x performance difference on AMD Zen 5
depending on PC alignment. When comparing the performance of AMD Zen 5 with
other CPUs using GCC-16 with -O3 -march=x86-64-v4. It's recommand to use patch
-p1 <patches/optional/782-lbm-zen5-prefetch-conflict.patch to avoid the
prefetch conflict issue which can cause significant performance degradation.
For other compilers or different flags on Zen 5, the align issue may be
different and need further manual tuning.
---------------cut end--------------------------------

[1]
https://github.com/OpenXiangShan/CPU2026LiteWrapper#note-for-lbm-on-amd-zen-5-with-gcc-16

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