This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/46551] Generate complex addressing mode CMP instruction in x86-64
- From: "dgohman at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 21 Jun 2011 14:26:42 +0000
- Subject: [Bug target/46551] Generate complex addressing mode CMP instruction in x86-64
- Auto-submitted: auto-generated
- References: <bug-46551-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46551
Dan Gohman <dgohman at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |dgohman at gmail dot com
--- Comment #2 from Dan Gohman <dgohman at gmail dot com> 2011-06-21 14:26:23 UTC ---
Something has noticed that in the else block, a is equal to the value loaded
from vm->cell[vm->index[0] - 2], so it is replacing the use of a and CSE'ing it
with the loaded value. That's what causes the loaded value to have multiple
uses, which presumably is why GCC subsequently declines to fold the addresssing
into the compare.