From: Jeff Law <jeffreyalaw@gmail.com>
To: apinski@marvell.com, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 4/4] Improve maybe_remove_writeonly_store to do a simple DCE for defining statement
Date: Tue, 19 Oct 2021 17:13:05 -0600 [thread overview]
Message-ID: <8fad2c2f-220f-b06a-6481-1dc8f250e3fe@gmail.com> (raw)
In-Reply-To: <1634619244-18969-5-git-send-email-apinski@marvell.com>
On 10/18/2021 10:54 PM, apinski--- via Gcc-patches wrote:
> From: Andrew Pinski <apinski@marvell.com>
>
> Instead of putting a full blow DCE after execute_fixup_cfg, it makes sense
> to try to remove the defining statement for the store that is being removed.
> Right now we only handle PHI node statements as there needs no extra checks
> except for it is only used once in the store statement.
>
> gcc/ChangeLog:
>
> * tree-cfg.c (maybe_remove_writeonly_store): Remove defining
> (PHI) statement of the store if possible.
This is the only part that I consider at all controversial.
Is the case you're trying to handle such that you have to eliminate the
PHI immediately and can't wait until the next DCE pass?
If so and we want to go this direction, should we pull this out into a
little routine? I'm a bit surprised we don't already have one or more
that do basically the same thing.
Jeff
next prev parent reply other threads:[~2021-10-19 23:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 4:54 [PATCH 0/4] Fix PR tree-opt/102703 apinski
2021-10-19 4:54 ` [PATCH 1/4] Add dump prints when execute_fixup_cfg removes a write only var store apinski
2021-10-19 23:10 ` Jeff Law
2021-10-19 4:54 ` [PATCH 2/4] Remove outdated comment about execute_fixup_cfg apinski
2021-10-19 23:10 ` Jeff Law
2021-10-19 4:54 ` [PATCH 3/4] Factor out removal of write only stores from execute_fixup_cfg apinski
2021-10-19 23:11 ` Jeff Law
2021-10-19 4:54 ` [PATCH 4/4] Improve maybe_remove_writeonly_store to do a simple DCE for defining statement apinski
2021-10-19 23:13 ` Jeff Law [this message]
2021-10-20 6:58 ` Richard Biener
2021-10-20 19:53 ` Jeff Law
2021-10-20 19:57 ` Andrew Pinski
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