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[Question, C6X] Under what situations should we disable DCE in sched2?
- From: Felix Yang <fei dot yang0953 at gmail dot com>
- To: gcc at gcc dot gnu dot org
- Cc: feilix dot yang at huawei dot com
- Date: Thu, 27 Mar 2014 21:50:51 +0800
- Subject: [Question, C6X] Under what situations should we disable DCE in sched2?
- Authentication-results: sourceware.org; auth=none
I find DCE in sched2 is disabled for C6X backend. Is this a
performance consideration? Or a GCC BUG?
And under what situations should we disable DCE in sched2?
Can anyone explain this? Many thanks.
The code snippet:
bool do_selsched = (c6x_flag_schedule_insns2 && flag_selective_scheduling2
&& !maybe_skip_selective_scheduling ());
/* Make sure the real-jump insns we create are not deleted. When modulo-
scheduling, situations where a reg is only stored in a loop can also
cause dead code when doing the initial unrolling. */
sched_no_dce = true;