From: Eric Botcazou <botcazou@adacore.com>
To: Claudiu Zissulescu Ianculescu <claziss@gmail.com>
Cc: gcc@gcc.gnu.org
Subject: Re: Possible regression in DF analysis
Date: Tue, 13 Dec 2022 09:41:32 +0100 [thread overview]
Message-ID: <4447258.LvFx2qVVIh@fomalhaut> (raw)
In-Reply-To: <CAL0iMy2P1-MrEs=4mE7-fFH5UAmE8JqeznKMtnWxyE-msT0o9g@mail.gmail.com>
> The problem shows in loop-doloop.c when I introduce a loop end pattern
> that replaces the first jump instruction (JUMP_INSN 15) with a pattern
> that clobbers CC reg. However, the DF doesn't look like it works as
> the doloop step cannot find the CC reg alive. Please see
> loop-doloop.c:766. Hence, it introduces the doloop_end patterns, and
> renders the compare instruction (INSN 14) dead code. leading to
> errors.
So df_get_live_out does not contain the CC register? iv_analysis_loop_init
only performs a local update of the DF information, maybe it does not cover
the basic block containing insn 14 and 15?
--
Eric Botcazou
next prev parent reply other threads:[~2022-12-13 8:41 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-08 10:40 Claudiu Zissulescu Ianculescu
2022-12-08 11:33 ` Eric Botcazou
2022-12-08 11:51 ` Claudiu Zissulescu Ianculescu
2022-12-13 8:41 ` Eric Botcazou [this message]
2022-12-13 12:30 ` Claudiu Zissulescu Ianculescu
2022-12-13 16:53 ` Claudiu Zissulescu Ianculescu
2022-12-13 17:01 ` Richard Biener
2022-12-13 17:38 ` Claudiu Zissulescu Ianculescu
2022-12-14 10:37 ` Claudiu Zissulescu Ianculescu
2022-12-14 11:06 ` Richard Biener
2022-12-14 11:30 ` Claudiu Zissulescu Ianculescu
2022-12-14 12:39 ` Richard Biener
2022-12-17 0:33 ` Jeff Law
[not found] ` <CAL0iMy1ad0PmprQdu6BMhHdivPz--1Yq72+n02Lj-SmxhZmxQQ@mail.gmail.com>
2022-12-20 12:34 ` Fwd: " Claudiu Zissulescu Ianculescu
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