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[Bug middle-end/30904] [dataflow] No longer optimizes shifts with large count
- From: "bonzini at gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 21 Feb 2007 16:23:57 -0000
- Subject: [Bug middle-end/30904] [dataflow] No longer optimizes shifts with large count
- References: <bug-30904-10053@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #6 from bonzini at gnu dot org 2007-02-21 16:23 -------
Created an attachment (id=13083)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13083&action=view)
patch to fix the bug
The logic in trunk's combine with respect to uninitialized variables is
correct.
We have to look at DF_LR_IN for the entry basic block to find variables that
are not used uninitialized.
In fact, the name of DF_UR_IN is misleading, as it computes *initialized*
registers.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30904