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[PATCH] local-factoring on TREE-SSA

Sorry, but in my last mail I forgot the subject! :(
Judit Jasz
---------------------------- Original Message ----------------------------
Date:    Fri, July 16, 2004 13:58


as Gabor Loki mentioned at the GCC Summit, we are trying to implement our
local factoring algorithm on TREE-SSA. (Earlier we sent our
algoritm, which works on RTL:

The attached patch contains a new TREE-SSA optimization phase, which
carries out statement hoisting (but currently it deals only with the
simpliest cases.) In the future we plan to add lots of improvements (e.g.
code sinking), but first we are interested in your opinions
about the current form of the algorithm.

Let's see the current results:
arm-elf: 0.143%
i686-linux: 0.085%
ppc-elf: 0.120%

(Measured on the CSiBE benchmark (v1.x.x). The figures represent code size
reduction compared to the mainline.)

The patch was regtested on {arm,ppc}-elf and i686-linux with no new failures.

So, what do you think? Is this patch OK for the mainline?

  Judit Jasz

2004-07-16 Judit Jasz <>

 * tree-ssa-lfact.c: New file.
 * (tree-ssa-lfact.o) Add.
 * common.opt: (ftree-lfact) New flag.
 * flags.h: (flag_tree_lfact): Declare.
 * opts.c: (decode_options): Set.
 * tree-optimize.c: (init_tree_optimization_passes): Add pass_tree_lfact.
* tree-pass.h: (pass_tree_lfact): Declare.

Attachment: hoisting.patch
Description: Text document

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