On Fri, Sep 18, 2026 at 03:44:33PM +0400, Alexey Charkov wrote: > Some decompressors rely on wide unaligned loads, which get very expensive > on strict alignment architectures such as ARM due to the need for the > compiler to reassemble each wide load byte at a time. > > On the other hand, some ARM platforms such as Rockchip enable the MMU and > d-cache early, making plain unaligned loads work too. > > Current Makefiles force the compiler to work around the unaligned loads > unconditionally, which in case of e.g. Zstd in SPL on Rockchip degrades > its performance by a factor of 4+ compared to native unaligned loads. > > Add an option for arches to opt out of the strict alignment flags for > decompressors, when they can guarantee that wide unaligned loads are safe. > > This improves the decompression performance and reduces the SPL size due > to fewer instructions generated per each unaligned load. > > CI for this series: > https://git.u-boot-project.org/u-boot/contributors/alchark/u-boot/-/pipelines/1322 > > Signed-off-by: Alexey Charkov <[email protected]>
So, as a good thing, I see this is already implemented in a cautious way. I would like the symbol name to be a bit more caution-forward. And the explanation in the help text should note the performance benefit, but be clearer that (a) it can only be used once certain conditions are met and then (b) is only removed from certain parts of the code and not globally. -- Tom
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