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Re: [rfc] subreg lowering pass / Overcoming double-set difficulties for CC re-use
- From: Steven Bosscher <stevenb dot gcc at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: BjÃrn Haase <bjoern dot m dot haase at web dot de>, denisc at overta dot ru, Roger Sayle <roger at eyesopen dot com>, Richard Henderson <rth at redhat dot com>
- Date: Sun, 11 Jun 2006 13:06:24 +0200
- Subject: Re: [rfc] subreg lowering pass / Overcoming double-set difficulties for CC re-use
- References: <Pine.LNX.4.44.0605280835280.26534-100000@www.eyesopen.com> <m3d5dq27ae.fsf@gossamer.airs.com> <200606111301.53514.bjoern.m.haase@web.de>
On Sunday 11 June 2006 13:01, BjÃrn Haase wrote:
> Putting all together, one would be replacing the present pass sequence
>
> ...
> NEXT_PASS (pass_combine);
> NEXT_PASS (pass_if_after_combine);
> NEXT_PASS (pass_partition_blocks);
> NEXT_PASS (pass_regmove);
> NEXT_PASS (pass_split_all_insns);
> ...
>
> by
>
> ...
> NEXT_PASS (pass_combine);
> NEXT_PASS (pass_if_after_combine);
> NEXT_PASS (pass_partition_blocks);
> NEXT_PASS (pass_regmove);
> NEXT_PASS (pass_use_split_for_exposing_CC_complexity);
> NEXT_PASS (pass_cse3);
> NEXT_PASS (pass_use_split_for_again_hiding_CC_complexity_and_possibly
> smashing_subregs);
> if (target_uses_subreg_lowering)
> {
> NEXT_PASS (pass_subreg_lowering_according_to_rth);
> NEXT_PASS (pass_cse4);
> }
> ...
Tearing it all apart, one would need to do something with CSE to make
it less slow before a pass_cse3 and pass_cse4 should even be considered.
Gr.
Steven