https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63184
--- Comment #29 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Andrew Pinski <pins...@gcc.gnu.org>: https://gcc.gnu.org/g:564efbf40077c25623cdd6ce2f911c56b5b08f6c commit r12-3364-g564efbf40077c25623cdd6ce2f911c56b5b08f6c Author: Andrew Pinski <apin...@marvell.com> Date: Mon Sep 6 00:52:18 2021 +0000 Fix PR tree-optimization/63184: add simplification of (& + A) != (& + B) These two testcases have been failing since GCC 5 but things have improved such that adding a simplification to match.pd for this case is easier than before. In the end we have the following IR: .... _5 = &a[1] + _4; _7 = &a + _13; if (_5 != _7) So we can fold the _5 != _7 into: (&a[1] - &a) + _4 != _13 The subtraction is folded into constant by ptr_difference_const. In this case, the full expression gets folded into a constant and we are able to remove the if statement. OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions. gcc/ChangeLog: PR tree-optimization/63184 * match.pd: Add simplification of pointer_diff of two pointer_plus with addr_expr in the first operand of each pointer_plus. Add simplificatoin of ne/eq of two pointer_plus with addr_expr in the first operand of each pointer_plus. gcc/testsuite/ChangeLog: PR tree-optimization/63184 * c-c++-common/pr19807-2.c: Enable for all targets and remove the xfail. * c-c++-common/pr19807-3.c: Likewise.