[wayoverthecloud]

In C++ there is the align_alloc specificier. https://en.cppreference.com/w/c/memory/aligned_alloc

Not sure for C

[ryanpetrich]

aligned_alloc is a C function. It doesn't help the compiler prove that two pointers can't alias. restrict is the keyword that does.

[bobmcnamara]

The compiler is allowed to assume the results of malloc and certain other allocation functions do not alias.

Restrict does too.