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| author | Martin Sebor <msebor@redhat.com> | 2019-10-09 21:35:11 +0000 |
|---|---|---|
| committer | Martin Sebor <msebor@gcc.gnu.org> | 2019-10-09 15:35:11 -0600 |
| commit | a7160771da8b77a03317aab2c27706ba70fe3e9c (patch) | |
| tree | d959d13c4cf04cf2f20c0cc56cd382c62d3b3b45 /gcc/calls.c | |
| parent | 89e0a492af5bec8ffa2ec5d99c4858df50d22c16 (diff) | |
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.
From-SVN: r276773
Diffstat (limited to 'gcc/calls.c')
| -rw-r--r-- | gcc/calls.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/calls.c b/gcc/calls.c index 51ad55f15a9..ae904473d0d 100644 --- a/gcc/calls.c +++ b/gcc/calls.c @@ -1614,6 +1614,10 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp) if (!get_attr_nonstring_decl (arg)) { c_strlen_data lendata = { }; + /* Set MAXBOUND to an arbitrary non-null non-integer + node as a request to have it set to the length of + the longest string in a PHI. */ + lendata.maxbound = arg; get_range_strlen (arg, &lendata, /* eltsize = */ 1); maxlen = lendata.maxbound; } @@ -1639,6 +1643,10 @@ maybe_warn_nonstring_arg (tree fndecl, tree exp) if (!get_attr_nonstring_decl (arg)) { c_strlen_data lendata = { }; + /* Set MAXBOUND to an arbitrary non-null non-integer + node as a request to have it set to the length of + the longest string in a PHI. */ + lendata.maxbound = arg; get_range_strlen (arg, &lendata, /* eltsize = */ 1); maxlen = lendata.maxbound; } |