On Monday, 4 June 2018 at 08:48:42 UTC, Kagamin wrote:
> On Saturday, 2 June 2018 at 11:44:40 UTC, Johan Engelen wrote:
>> LLVM is not yet smart enough to optimize adjacent stores
>
> I thought it tries to account for memory access errors: depending on how the processor checks memory access the first bytes might not be stored.

Invalid accesses do not need to be taken into account, because they are UB. So it is perfectly legal to combine the stores. LLVM does do that in some cases, just not in this particular case.  (GCC does optimize it well btw)

- Johan