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Re: [PATCH] Rerun df_analyze after delete_unmarked_insns during DCE
- From: Bernd Schmidt <bernds at codesourcery dot com>
- To: Jeff Law <law at redhat dot com>
- Cc: Alexey Makhalov <makhaloff at gmail dot com>, Vladimir Makarov <vmakarov at redhat dot com>, <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 21 Aug 2013 12:41:09 +0200
- Subject: Re: [PATCH] Rerun df_analyze after delete_unmarked_insns during DCE
- References: <CALd+sgf5prkuJivpwvYvh86gyiUTq_pHcv9z7Gh3Sk+aZzBNqg at mail dot gmail dot com> <52128897 dot 40108 at redhat dot com>
On 08/19/2013 11:05 PM, Jeff Law wrote:
> On 07/20/2013 03:02 AM, Alexey Makhalov wrote:
>> Hello!
>>
>> If delete_unmarked_insns deletes some insn, DF state might be
>> out of date, and, regs_ever_live might contain unused registers till
>> the end.
(I can't find the original mail either in my mailbox or in the archives).
If this happens after reload, then regs_ever_live really should stay the
same, since we used it to compute frame offsets and such.
Also, df_analyze calls df_compute_regs_ever_live with reset=false, so it
shouldn't delete anything from the set?
Bernd