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[Bug c/66348] Simple loop has only lower half of the 64-bit counter initialized correctly
- From: "pinskia at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 30 May 2015 22:46:39 +0000
- Subject: [Bug c/66348] Simple loop has only lower half of the 64-bit counter initialized correctly
- Auto-submitted: auto-generated
- References: <bug-66348-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66348
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I suspect there is an alias violation here rather what is described.
In x86_64, almost all of the instructions which act on 32bit half of the
registers will zero extend. That includes xorl.