From: Alan Modra <amodra@gmail.com>
To: will schmidt <will_schmidt@vnet.ibm.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>,
gcc-patches@sourceware.org
Subject: Re: [RS6000] rs6000_rtx_costs for AND
Date: Wed, 16 Sep 2020 16:54:13 +0930 [thread overview]
Message-ID: <20200916072412.GN5452@bubble.grove.modra.org> (raw)
In-Reply-To: <e61a4ee92b0aa1753f37c46527b570da5d6712d8.camel@vnet.ibm.com>
On Tue, Sep 15, 2020 at 01:15:34PM -0500, will schmidt wrote:
> On Tue, 2020-09-15 at 10:49 +0930, Alan Modra via Gcc-patches wrote:
> > The existing "case AND" in this function is not sufficient for
> > optabs.c:avoid_expensive_constant usage, where the AND is passed in
> > outer_code.
> >
> > * config/rs6000/rs6000.c (rs6000_rtx_costs): Move costing for
> > AND to CONST_INT case.
[snip]
> It's not exactly 1x1.. I tentatively conclude that the /* rotate-and-
> mask */ lump of code here does go dead with the "case AND" changes
> above.
It's not so much dead as duplicate. When rtx_costs returns false, as
it will now on sub-expressions matching the removed code, it will be
called recursively on the sub-expressions with outer_code set to the
operation, AND in this case.
--
Alan Modra
Australia Development Lab, IBM
next prev parent reply other threads:[~2020-09-16 7:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 1:19 [RS6000] rtx_costs Alan Modra
2020-09-15 1:19 ` [RS6000] Count rldimi constant insns Alan Modra
2020-09-15 22:29 ` Segher Boessenkool
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs for PLUS/MINUS constant Alan Modra
2020-09-15 22:31 ` Segher Boessenkool
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs for AND Alan Modra
2020-09-15 18:15 ` will schmidt
2020-09-16 7:24 ` Alan Modra [this message]
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs comment Alan Modra
2020-09-16 23:21 ` Segher Boessenkool
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs multi-insn constants Alan Modra
2020-09-16 23:28 ` Segher Boessenkool
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs cost IOR Alan Modra
2020-09-17 0:02 ` Segher Boessenkool
2020-09-17 3:42 ` Alan Modra
2020-09-21 15:49 ` Segher Boessenkool
2020-09-21 23:54 ` Alan Modra
2020-09-15 1:19 ` [RS6000] rs6000_rtx_costs reduce cost for SETs Alan Modra
2020-09-17 17:51 ` Segher Boessenkool
2020-09-18 3:38 ` Alan Modra
2020-09-18 18:13 ` Segher Boessenkool
2020-09-21 7:07 ` Alan Modra
2020-09-15 1:19 ` [RS6000] rotate and mask constants Alan Modra
2020-09-15 7:16 ` Alan Modra
2020-09-21 15:56 ` Segher Boessenkool
2020-09-15 18:15 ` [RS6000] rtx_costs will schmidt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200916072412.GN5452@bubble.grove.modra.org \
--to=amodra@gmail.com \
--cc=gcc-patches@sourceware.org \
--cc=segher@kernel.crashing.org \
--cc=will_schmidt@vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).