https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95757
--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:ff92ede8d269375f800e1b347a48f4698874b4a3 commit r11-7448-gff92ede8d269375f800e1b347a48f4698874b4a3 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Mar 2 11:49:12 2021 +0100 vrp: Improve register_edge_assert_for [PR95757] The Wstringop-overflow-25.c testcase doesn't emit one of the expected warnings on targets that don't do short curcuiting due to target costs (or e.g. with --param=logical-op-non-short-circuit=0 on all targets). The problem is that only reassoc2 optimizes: _49 ={v} unsigned_value_source; if (_49 == 0) goto <bb 7>; [50.00%] else goto <bb 5>; [50.00%] <bb 5> [local count: 536870913]: if (_49 > 2) goto <bb 7>; [50.00%] else goto <bb 6>; [50.00%] <bb 6> [local count: 268435457]: _53 = _49 + 1; into: _49 ={v} unsigned_value_source; _48 = _49 + 18446744073709551615; _1 = _48 > 1; if (_1 != 0) goto <bb 6>; [50.00%] else goto <bb 5>; [50.00%] <bb 5> [local count: 268435457]: _53 = _49 + 1; (but, note the _1 = _48 > 1; if (_1 != 0)), then dom3 is run and because of that if (_1 != 0) vs. if (_48 > 1) doesn't register edge asserts for _48 and _49) and so we don't get SSA_NAME_RANGE_INFO for _53 (and ditto for vrp2) and only afterwards comes forwprop4 that canonicalizes it to if (_48 > 1). While with --param=logical-op-non-short-circuit=1 it is already reassoc1 that optimizes it and forwprop3 that propagates it, so we have on the SSA_NAME corresponding to _53 above SSA_NAME_RANGE_INFO and during expansion we warn. The following patch fixes it by handling those not yet propagated comparisons into GIMPLE_COND in register_edge_assert_for. We already have all the infrastructure there to handle the --param=logical-op-non-short-circuit=1 | and &s. 2021-03-02 Jakub Jelinek <ja...@redhat.com> PR middle-end/95757 * tree-vrp.c (register_edge_assert_for): Remove superfluous ()s around condition. Call register_edge_assert_for_1 for == 0, != 0, == 1 and != 1 comparisons if name is lhs of a comparison.
