Linus Torvalds writes: (Summary) On Fri, Mar 9, 2018 at 4:32 PM, Andrew Morton <akpm@linux-foundation.org> wrote:
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I wonder which gcc versions actually accept Kees's addition. Note that we already do have this pattern, as seen by: Note that we already do have this pattern, as seen by:git grep -2 __builtin_choose_expr | grep -2 __builtin_constant_p which show drivers/pinctrl/intel/pinctrl-intel.h, so the pattern already exists current kernels and _works_ - it apparently just doesn't work in slightly more complicated cases. It's one reason why I wondered if simplifying the expression to have just that single __builtin_constant_p() might not end up working..