On Fri, May 8, 2026 at 8:59 AM Basile STARYNKEVITCH
<[email protected]> wrote:
>
> Hello all,
>
> Assume GCC16 (or future GCC17) targetting a common Von Neumann 64 bits
> architecture (eg RISCV, AMD64, ARM-Aarch64, POWERPC-64).
>
> Are there cases where the pointed type changes the generated code.
>
> To be more concrete, I am thinking of generated C99 or C17 code (not
> human written one).
>
> If every generated pointer was void* and at every dereferencing
> occurrence explicitly casted to the actual data pointer, does that make
> any difference in generated assembler code?
>
> In other words, is declaring only void* fields and local variables and
> casting them on every dereferencing use makes a difference in generated
> code.
>
> My guess is no, but I could be wrong.
It makes a difference if the pointers reside in memory and for the
access to that. struct { void *p; } vs. struct { int *p; } behaves
differently wrt TBAA.
>
> Thanks
>
> --
>
> Basile STARYNKEVITCH
> <[email protected]>
> 8 rue de la Faïencerie
> http://starynkevitch.net/Basile/
> 92340 Bourg-la-Reine
> https://github.com/bstarynk
> France
> https://github.com/RefPerSys/RefPerSys
> https://orcid.org/0000-0003-0908-5250
