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Does anyone have Vlad's CSE speedup patches from many years ago
- From: Steven Bosscher <stevenb dot gcc at gmail dot com>
- To: gcc at gcc dot gnu dot org
- Cc: law at redhat dot com, vmakarov at redhat dot com, wilson at specifixinc dot com, ian at airs dot com
- Date: Sun, 28 May 2006 23:23:18 +0200
- Subject: Does anyone have Vlad's CSE speedup patches from many years ago
Hello,
When fwprop gets approved, CSE path following will disappear. We lose
virtually no optimization opportunities. Still, it should not be very
hard to make CSE work on extended basic blocks (but without rescanning
like path following does). All that would be needed is infrastructure
in cse.c to do a pre-order walk starting from some basic block, and a
way to store and roll-back the state of the various tables that cse.c
builds.
I found out long ago that even longer ago Vlad had patches to keep the
state for basic blocks and re-using it. The latest message mentioning
this work is http://gcc.gnu.org/ml/gcc-patches/2001-02/msg01166.html,
and apparently Vlad's patches never made it out of the Cygnus network.
So...
Does anyone of you pack-rats still have these patches? Maybe there is
code in them that I can re-use, or at least learn from because right
now, even in my cleaned-up-and-cut-down version of cse.c (down to 5000
lines) I still can't make a whole lot of sense of all the tables that
are used in that pass.
I hope[*] you can help. Thanks,
Gr.
Steven
[*] I know hope is delayed disappointment, but trying doesn't hurt ;-)