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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/63989] tree-ssa-strlen.c doesn't handle constant pointer plus and array refs if constant offset is smaller than known constant string length Date: Thu, 20 Nov 2014 09:44:00 -0000 [thread overview] Message-ID: <bug-63989-4-3H7dKGVsg7@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-63989-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63989 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2014-11-20 Ever confirmed|0 |1 --- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> --- So, we are talking here about e.g. int f1 (char *p) { __builtin_strcpy (p, "foobar"); return __builtin_strlen (p + 2); } int f2 (char *p) { __builtin_strcpy (p, "foobar"); p[2] = '\0'; return __builtin_strlen (p); } int f3 (char *p) { __builtin_strcpy (p, "foobar"); p[2] = '\0'; return __builtin_strlen (p + 3); } int f4 (char *p) { __builtin_strcpy (p, "foobar"); p[2] = 'z'; return __builtin_strlen (p); } and then also determining using get_string_length (if constant) whether a character pointer dereference is known to be zero or known to be non-zero.
next prev parent reply other threads:[~2014-11-20 9:44 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-11-20 9:31 [Bug tree-optimization/63989] New: " jakub at gcc dot gnu.org 2014-11-20 9:44 ` jakub at gcc dot gnu.org [this message] 2014-11-20 11:20 ` [Bug tree-optimization/63989] " rguenther at suse dot de 2014-11-21 9:38 ` jakub at gcc dot gnu.org 2014-12-08 17:25 ` jakub at gcc dot gnu.org 2015-01-08 21:31 ` jakub at gcc dot gnu.org 2015-04-22 12:01 ` jakub at gcc dot gnu.org 2015-07-16 9:18 ` rguenth at gcc dot gnu.org 2022-01-09 0:45 ` pinskia at gcc dot gnu.org
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