alt Hacker News> If some architecture traps on unaligned access, then the compiler can and should simply generate the correct code so that it loads the integer piece by piece instead.
Wouldn't the compiler have to assume that every pointer access might be unaligned and do the slow "piece by piece" access every time? It can hardly guess the runtime value of a pointer during compilation.
It should be able to make a lot of inferences. For example, taking the address of some value allocated by the compiler itself results in an aligned pointer unless the programmer overrides it. Compiler should be able to trace it from there. Pointers from malloc are also aligned.
If compiler is not doing it for some reason, __builtin_assume_aligned can be used to explicitly mark a pointer as aligned.