Re: [patch] Loop aware cfg cleanup

[Jeffrey A Law <law at redhat dot com>]

On Thu, 2005-03-03 at 19:36 +0100, Zdenek Dvorak wrote:
> Hello,
> 
> this patch adds cfgcleanup call after loop unswitching and complete
> loop unrolling, thus making it possible for the further loop
> optimizations to take advantage of the code simplification
> (currently, old loops are not removed during complete loop unrolling,
> the consecutive basic blocks are not merged, etc.,  thus making it very
> problematic for the remaining loop optimization to work with the
> affected loops).
> 
> To minimize the compile time impact, rewrite_into_loop_closed_ssa
> is modified so that it only rewrites the ssa form if necessary
> (i.e. if some code is moved outside of the loop due to cfg cleanup
> call).
> 
> Bootstrapped & regtested on i686 and x86_64 (with -funroll-loops
> -funswitch-loops).
> 
> Zdenek
> 
> 	* Makefile.in (tree-optimize.o): Add CFGLOOP_H dependence.
> 	* cfgloop.c (flow_loop_nodes_find): Export.
> 	* cfgloop.h (flow_loop_nodes_find, fix_loop_structure):
> 	Declare.
> 	* cfgloopmanip.c (fix_loop_structure): New function.
> 	* predict.c (predict_loops): Clean up the loops information.
> 	* tree-cfg.c (cleanup_tree_cfg_loop): New function.
> 	(tree_can_merge_blocks_p, remove_bb, tree_forwarder_block_p): Respect
> 	loop structure.
> 	* tree-flow.h (cleanup_tree_cfg_loop): Declare.
> 	(rewrite_into_loop_closed_ssa): Declaration changed.
> 	* tree-loop-linear.c (linear_transform_loops): Add argument to
> 	rewrite_into_loop_closed_ssa call.
> 	* tree-ssa-loop-ch.c (copy_loop_headers): Ditto.
> 	* tree-ssa-loop-im.c (move_computations): Ditto.
> 	* tree-ssa-loop.c (tree_loop_optimizer_init): Ditto.
> 	* tree-vectorizer.c (vectorize_loops): Ditto.
> 	* tree-optimize.c: Include cfgloop.h.
> 	(execute_todo): Choose whether to call cleanup_tree_cfg or
> 	cleanup_tree_cfg_loop.
> 	* tree-ssa-loop-ivcanon.c (canonicalize_loop_induction_variables,
> 	(tree_unroll_loops_completely): Enable cleanup_tree_cfg_loop call.
> 	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops): Enable
> 	cleanup_tree_cfg_loop call.
> 	* tree-ssa-loop-manip.c (find_uses_to_rename_bb): New function.
> 	(find_uses_to_rename, rewrite_into_loop_closed_ssa): Support
> 	work on part of cfg.
This is fine.  Please install into the mainline sources.

Thanks,
jeff