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Re: PATCH PING: stop ivopts from pessimizing code (PR42505)
- From: Zdenek Dvorak <rakdver at kam dot mff dot cuni dot cz>
- To: Sandra Loosemore <sandra at codesourcery dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 2 Jul 2010 16:07:07 +0200
- Subject: Re: PATCH PING: stop ivopts from pessimizing code (PR42505)
- References: <4C2DD6D9.firstname.lastname@example.org>
what are the effects on the compile time? The tree-ssa-loop-ivopts.c part of the
patch is OK, assuming that they are negligible.
>> 2010-06-18 Sandra Loosemore <email@example.com>
>> PR middle-end/42505
>> * tree-ssa-loop-ivopts.c (determine_set_costs): Delete obsolete
>> comments about cost model.
>> (try_add_cand_for): Add second strategy for choosing initial set
>> based on original IVs, controlled by ORIGINALP argument.
>> (get_initial_solution): Add ORIGINALP argument.
>> (find_optimal_iv_set_1): New function, split from find_optimal_iv_set.
>> (find_optimal_iv_set): Try two different strategies for choosing
>> the IV set, and return the one with lower cost.
As for this change:
>> * cfgloopanal.c (init_set_costs): Use call_used_regs rather than
>> fixed_regs to count number of registers available for loop variables.
Should not we make call_used_regs unavailable only if there is a function call in the