On 14/02/15 22:10, Dean Long wrote: > On 2/14/2015 12:07 AM, Andrew Haley wrote: >> On 02/13/2015 10:52 PM, Dean Long wrote: >> >>> My understanding is that whether or not aarch64 allows unaligned >>> accesses is based on a system setting, so this change is too >>> simplistic. >> >> Disabling unaligned access would be a really perverse thing to do, and >> I suspect that GCC and glibc already assume that unaligned accesses >> work so it would require a recompilation of libjvm (and probably the >> whole OS) to make it work. However, if you really think there's a >> point to making this a runtime flag I won't resist. > > Even if linux-aarch64 always allows unaligned, checking only for > "aarch64" is not future-proof because it doesn't take the OS into > account.
Sure, but we can't predict all the crazy things that writers of future operating systems might do. > However, I really don't like having to enumerate all relevant > platforms in multiple places in shared code, so I disagree with the > existing code and with perpetuating the pattern. As long as the > decision is in platform-specific code, a build-time decision may be > entirely appropriate. That makes sense. I don't like the way that the decision is hidden in shared code either: if it had been in a more obvious place I would have found it earlier. I'll have a look at writing an Unsafe method which does the right thing. Andrew.
