https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107831
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Petr Skocik from comment #1)
> Sidenote regarding the stack-allocating code for cases when the size is not
> known to be less than pagesize: the code generated for those cases is quite
> large. It could be replaced (at least under -Os) with a call to a special
> assembly function that'd pop the return address (assuming the target machine
> pushes return addresses to the stack), allocate adjust and allocate the
> stack size in a piecemeal fashion so as to not skip guard pages, the repush
> the return address and return to caller with the stacksize expanded.
You certainly don't want to kill the return stack the CPU has, even if it
results in a few saved bytes for -Os.
