https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90879
--- Comment #3 from Martin Sebor ---
Author: msebor
Date: Wed Oct 9 21:35:11 2019
New Revision: 276773
URL: https://gcc.gnu.org/viewcvs?rev=276773=gcc=rev
Log:
PR tree-optimization/90879 - fold zero-equality of strcmp between a longer
string and a smaller array
gcc/c-family/ChangeLog:
PR tree-optimization/90879
* c.opt (-Wstring-compare): New option.
gcc/testsuite/ChangeLog:
PR tree-optimization/90879
* gcc.dg/Wstring-compare-2.c: New test.
* gcc.dg/Wstring-compare.c: New test.
* gcc.dg/strcmpopt_3.c: Scan the optmized dump instead of strlen.
* gcc.dg/strcmpopt_6.c: New test.
* gcc.dg/strlenopt-65.c: Remove uinnecessary declarations, add
test cases.
* gcc.dg/strlenopt-66.c: Run it.
* gcc.dg/strlenopt-68.c: New test.
gcc/ChangeLog:
PR tree-optimization/90879
* builtins.c (check_access): Avoid using maxbound when null.
* calls.c (maybe_warn_nonstring_arg): Adjust to get_range_strlen
change.
* doc/invoke.texi (-Wstring-compare): Document new warning option.
* gimple-fold.c (get_range_strlen_tree): Make setting maxbound
conditional.
(get_range_strlen): Overwrite initial maxbound when non-null.
* gimple-ssa-sprintf.c (get_string_length): Adjust to get_range_strlen
changes.
* tree-ssa-strlen.c (maybe_diag_stxncpy_trunc): Same.
(used_only_for_zero_equality): New function.
(handle_builtin_memcmp): Call it.
(determine_min_objsize): Return an integer instead of tree.
(get_len_or_size, strxcmp_eqz_result): New functions.
(maybe_warn_pointless_strcmp): New function.
(handle_builtin_string_cmp): Call it. Fold zero-equality of strcmp
between a longer string and a smaller array.
(get_range_strlen_dynamic): Overwrite initial maxbound when non-null.
Added:
trunk/gcc/testsuite/gcc.dg/Wstring-compare-2.c
trunk/gcc/testsuite/gcc.dg/Wstring-compare.c
trunk/gcc/testsuite/gcc.dg/strcmpopt_6.c
trunk/gcc/testsuite/gcc.dg/strlenopt-69.c
Modified:
trunk/gcc/ChangeLog
trunk/gcc/builtins.c
trunk/gcc/c-family/ChangeLog
trunk/gcc/c-family/c.opt
trunk/gcc/calls.c
trunk/gcc/doc/invoke.texi
trunk/gcc/gimple-fold.c
trunk/gcc/gimple-ssa-sprintf.c
trunk/gcc/testsuite/ChangeLog
trunk/gcc/testsuite/gcc.dg/strcmpopt_3.c
trunk/gcc/testsuite/gcc.dg/strlenopt-65.c
trunk/gcc/testsuite/gcc.dg/strlenopt-66.c
trunk/gcc/tree-ssa-strlen.c
