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newpavlovyesterday at 10:47 AM1 replyview on HN

>So just use misaligned loads if Zicclsm is supported.

LLVM and GCC developers clearly disagree with you. In other words, re-iterating the previously raised point: Zicclsm is effectively useless and we have to wait decades for hypothetical Oilsm.

Most programmers will not know that the misaligned issue even exists, even less about options like -mno-strict-align. They just will compile their project with default settings and blame RISC-V for being slow.

RISC-V could've easily avoided all this mess by properly mandating misaligned pointer handling as part of the I extension.


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dzaimayesterday at 11:36 AM

Well, we don't necessarily have to wait for Oilsm; software that wants to could just choose to be opinionated and run massively-worse on suboptimal hardware. And, of course, once Oilsm hardware becomes the standard, it'd be fine to recompile RVA23-targeting software to it too.

> RISC-V could've easily avoided all this mess by properly mandating misaligned pointer handling as part of the I extension.

Rather hard to mandate performance by an open ISA. Especially considering that there could actually be scenarios where it may be necessary to chicken-bit it off; and of course the fact that there's already some questionability on ops crossing pages, where even ARM/x86 are very slow.

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