https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99780
--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> --- It's the same story we saw for no_stack_protector attribute: --param stack-clash-protection-guard-size=12 --param stack-clash-protection-probe-interval=12 + '#pragma GCC optimize 1' is not equal to: --param stack-clash-protection-guard-size=12 --param stack-clash-protection-probe-interval=12 -O1 btw. the default of 16 comes from here: { OPT_LEVELS_ALL, OPT__param_stack_clash_protection_guard_size_, NULL, DEFAULT_STK_CLASH_GUARD_SIZE == 0 ? 16 : DEFAULT_STK_CLASH_GUARD_SIZE }, and that's why I suggested: https://gcc.gnu.org/pipermail/gcc-patches/2020-October/556929.html So something for GCC 12. Now let's take a look at the verify_curr_properties.