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[Bug tree-optimization/28230] [4.2 Regression] -O2 -fwrapv miscompiles gcc, binutils, gzip.
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 10 Oct 2006 14:32:50 -0000
- Subject: [Bug tree-optimization/28230] [4.2 Regression] -O2 -fwrapv miscompiles gcc, binutils, gzip.
- References: <bug-28230-7667@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #17 from rguenth at gcc dot gnu dot org 2006-10-10 14:32 -------
No, it's extract_range_from_binary_expr operating on [0, +INF] + [0, 65535] and
blindly using int_const_binop to compute the resulting range...
I believe the following is completely bogus and we cannot ignore overflows
in range arithmetic for wrapv either.
static inline tree
vrp_int_const_binop (enum tree_code code, tree val1, tree val2)
{
tree res;
if (flag_wrapv)
return int_const_binop (code, val1, val2, 0);
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |rguenth at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
Last reconfirmed|2006-09-21 03:31:17 |2006-10-10 14:32:50
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28230