https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121478
--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:8b41e021ba4ad8db6a6cbd512c8c42277909c402 commit r16-3334-g8b41e021ba4ad8db6a6cbd512c8c42277909c402 Author: Andrew Pinski <andrew.pin...@oss.qualcomm.com> Date: Wed Aug 20 15:34:15 2025 -0700 c: Add folding of nullptr_t in some cases [PR121478] The middle-end does not fully understand NULLPTR_TYPE. So it gets confused a lot of the time when dealing with it. This adds the folding that is similarly done in the C++ front-end already. In some cases it should produce slightly better code as there is no reason to load from a nullptr_t variable as it is always NULL. The following is handled: nullptr_v ==/!= nullptr_v -> true/false (ptr)nullptr_v -> (ptr)0, nullptr_v f(nullptr_v) -> f ((nullptr, nullptr_v)) The last one is for conversion inside ... . Bootstrapped and tested on x86_64-linux-gnu. PR c/121478 gcc/c/ChangeLog: * c-fold.cc (c_fully_fold_internal): Fold nullptr_t ==/!= nullptr_t. * c-typeck.cc (convert_arguments): Handle conversion from nullptr_t for varargs. (convert_for_assignment): Handle conversions from nullptr_t to pointer type specially. gcc/testsuite/ChangeLog: * gcc.dg/torture/pr121478-1.c: New test. Signed-off-by: Andrew Pinski <andrew.pin...@oss.qualcomm.com>
