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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/54783] [4.8 Regression] valgrind reports using uninitialised data in mark_pseudo_regno_live and make_object_born on basic code Date: Wed, 03 Oct 2012 06:34:00 -0000 [thread overview] Message-ID: <bug-54783-4-w1ABQA64yc@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-54783-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54783 Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mpolacek at gcc dot gnu.org --- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> 2012-10-03 06:34:18 UTC --- Not a bug, probably. Valgrind ought to be used only when --enable-checking=valgrind. Otherwise we have to live with those sparseset warnings, as those valgrind markups aren't compiled in. The thing is in gcc-4.7 sparseset_alloc we have: /* We use xcalloc rather than xmalloc to silence some valgrind uninitialized read errors when accessing set->sparse[n] when "n" is not, and never has been, in the set. These uninitialized reads are expected, by design and harmless. If this turns into a performance problem due to some future additional users of sparseset, we can revisit this decision. */ sparseset set = (sparseset) xcalloc (1, n_bytes); But in trunk sparseset_alloc there's: sparseset set = XNEWVAR(struct sparseset_def, n_bytes); /* Mark the sparseset as defined to silence some valgrind uninitialized read errors when accessing set->sparse[n] when "n" is not, and never has been, in the set. These uninitialized reads are expected, by design and harmless. */ VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (set, n_bytes));
next prev parent reply other threads:[~2012-10-03 6:34 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-10-02 19:56 [Bug rtl-optimization/54783] New: " zsojka at seznam dot cz 2012-10-03 6:34 ` mpolacek at gcc dot gnu.org [this message] 2012-10-03 6:54 ` [Bug rtl-optimization/54783] " jakub at gcc dot gnu.org 2012-10-04 12:18 ` rguenth at gcc dot gnu.org 2012-11-13 7:29 ` jakub at gcc dot gnu.org 2012-12-07 11:46 ` rguenth at gcc dot gnu.org
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