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[Bug tree-optimization/9814] gcc fails to optimise if (l&2) l|=2 away
- From: "roger at eyesopen dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 22 May 2005 19:25:25 -0000
- Subject: [Bug tree-optimization/9814] gcc fails to optimise if (l&2) l|=2 away
- References: <20030223074600.9814.181096@bugs.debian.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From roger at eyesopen dot com 2005-05-22 19:25 -------
I posted a patch here: http://gcc.gnu.org/ml/gcc-patches/2005-03/msg01956.html
to implement this in the RTL optimizers. Better to get it linked to the PR,
than slip through the cracks. The proposed change to noce_emit_move_insn is
also related to another missed optimization PR, whose number I can no longer
remember. Something to do with synthesized insn not getting recognized without
the needed clobbers.
I agree with Kazu that these transformations should also be implemented at the
tree-ssa level. I think once I commit the RTL solution to mainline CVS (so these
optimizations are performed somewhere), I'll unassign the PR (from myself), and
leave the tree-optimization PR open as an enhancement request.
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What |Removed |Added
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Keywords| |patch
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=9814