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[Bug tree-optimization/38440] auto-increment generation does not work
- From: "amylaar at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 9 Dec 2008 21:13:32 -0000
- Subject: [Bug tree-optimization/38440] auto-increment generation does not work
- References: <bug-38440-5394@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #4 from amylaar at gcc dot gnu dot org 2008-12-09 21:13 -------
The .083t.cunroll (gcc 4.2.1) and .1045.cunroll (gcc 4.4.0) dumps
show that the read memory read pointers are incremented as given in the
source.
This is still the case in the .085.ivopts dump from gcc 4.2.1, but no more
in the .017.ivopts dump of gcc 4.4.0 . There, the code is pessimized
to use a newly invented index and add this to the initial values of the
read pointers and size to arrive at their current values - the opposite of
strength reduction.
With this pessimized code, we can't form any auto-increments.
--
amylaar at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|rtl-optimization |tree-optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38440