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Re: Fwd: [PATCH] Scheduling result adjustment to enable macro-fusion
- From: Wei Mi <wmi at google dot com>
- To: Alexander Monakov <amonakov at ispras dot ru>
- Cc: Steven Bosscher <stevenb dot gcc at gmail dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, David Li <davidxl at google dot com>
- Date: Tue, 10 Sep 2013 09:05:37 -0700
- Subject: Re: Fwd: [PATCH] Scheduling result adjustment to enable macro-fusion
- Authentication-results: sourceware.org; auth=none
- References: <CA+4CFy60EZ99xBGecerYLM9wD6w2v60SpJsfOGguA_PWLLupsA at mail dot gmail dot com> <CA+4CFy6+1ieFJ5+vvsStYs8AnfUY+aAVrYR-p-T7iPisVLCWHQ at mail dot gmail dot com> <alpine dot LNX dot 2 dot 00 dot 1309041253370 dot 5281 at monopod dot intra dot ispras dot ru> <CABu31nONs_DJ99YXDyWAE2a5iyoQWQyuGwLm0jrcb+mCx2M1Aw at mail dot gmail dot com> <CABtfrpCU1jkTZvA-cZ99bjhBnvQMTkNxHMDhhmkAa_k891T1zw at mail dot gmail dot com> <CA+4CFy5A2Nk-yUfQNZYQQd+O93mcJYBVty9S_5sd9VFinxmYdg at mail dot gmail dot com> <CA+4CFy4M8ckX3g8xCQEV+g4SdWgy742oBiGSep4GM74q3paVzA at mail dot gmail dot com> <alpine dot LNX dot 2 dot 00 dot 1309101543040 dot 2373 at monopod dot intra dot ispras dot ru>
Because deps_analyze_insn only analyzes data deps but no control deps.
Control deps are included by add_branch_dependences. Without the
chain_to_prev_insn in the end of add_branch_dependences, jmp will be
control dependent on every previous insn in the same bb, and the cmp
and jmp group could still be scheduled apart since they will not be
put in ready list at the same time.
On Tue, Sep 10, 2013 at 4:44 AM, Alexander Monakov <amonakov@ispras.ru> wrote:
>
>
> On Fri, 6 Sep 2013, Wei Mi wrote:
>
>> SCHED_GROUP works after I add chain_to_prev_insn after
>> add_branch_dependences, in order to chain control dependences to prev
>> insn for sched group.
>
> chain_to_prev_insn is done in the end of deps_analyze_insn, why is that not
> sufficient?
>
> Alexander