[chrisseaton]

Yes you can implement C in other ways (I've worked on a C JIT that abstracts from this flat memory model, for example) but come on we all know this is how C works on most machines most of the time and they shouldn't need to add a lot of disclaimers that it could theoretically be done a different way when they're just trying to raise awareness of how things work in practice.

[rayiner]

The issue is that C does not work that way on modern machines. Not that old Alpha machines had doubleword aligned pointer and no byte or word load instructions. So indexes into the array had to be multiples of 4. More important, aliasing rules preclude treating memory like one big array: https://gist.github.com/shafik/848ae25ee209f698763cffee272a5.... C99 and newer go to some lengths to permit the optimizer for treat pointers as pointing into disjoint byte ranges (which allows the optimizer to assume they cannot alias). Accordingly the mental model of a big array of memory is, at least for C, generally unsound.

[comex]

Nitpick: The same rules were also present in C89.

[rayiner]

Thanks for the correction!