https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104009
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Siddhesh Poyarekar <siddh...@gcc.gnu.org>: https://gcc.gnu.org/g:17df585a3a6a852c71883cc2ff40e111a6875149 commit r12-6568-g17df585a3a6a852c71883cc2ff40e111a6875149 Author: Siddhesh Poyarekar <siddh...@gotplt.org> Date: Fri Jan 14 08:56:15 2022 +0530 tree-optimization/104009: Conservative underflow estimate in object size Restrict negative offset computation only to dynamic object sizes, where size expressions are accurate and not a maximum/minimum estimate and in cases where negative offsets definitely mean an underflow, e.g. in MEM_REF of the whole object with negative ofset in addr_object_size. This ends up missing some cases where __builtin_object_size could have come up with more precise results, so tests have been adjusted to reflect that. gcc/ChangeLog: PR tree-optimization/104009 * tree-object-size.c (compute_builtin_object_size): Bail out on negative offset. (plus_stmt_object_size): Return maximum of wholesize and minimum of 0 for negative offset. gcc/testsuite/ChangeLog: PR tree-optimization/104009 * gcc.dg/builtin-object-size-1.c (test10): New test. * gcc.dg/builtin-object-size-3.c (test10): Likewise. (test9): Expect zero size for negative offsets. * gcc.dg/builtin-object-size-4.c (test8): Likewise. * gcc.dg/builtin-object-size-5.c (test7): Drop test for __builtin_object_size. Signed-off-by: Siddhesh Poyarekar <siddh...@gotplt.org>
