From: Jeff Law <jeffreyalaw@gmail.com>
To: Navid Rahimi <navidrahimi@microsoft.com>,
Navid Rahimi via Gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [EXTERNAL] Re: [PATCH][WIP] PR tree-optimization/101808 Boolean comparison simplification
Date: Tue, 23 Nov 2021 13:14:30 -0700 [thread overview]
Message-ID: <a510dcfc-84fe-c9dc-f142-203a9730df48@gmail.com> (raw)
In-Reply-To: <BN6PR21MB0162D1BAF21759D1B57C2099A3609@BN6PR21MB0162.namprd21.prod.outlook.com>
On 11/23/2021 1:08 PM, Navid Rahimi wrote:
>> In gimple your primary goal should be to reduce the number of
>> expressions that are evaluated. This patch does the opposite.
> That is actually a really good point in my opinion. I am hesitant about this patch and wanted to hear gcc-patch opinion about this. Doing something like this in IR level is a little bit counter intuitive to me. I will take a look at LLVM in my spare time to see where they are transferring that pattern and what was the rationale behind it.
It could be easily looked at as target expansion issue. ie, there's two
equivalent forms for the full expression and the desired form varies
based on some property of the target. The idea we've kicked around, but
not implemented, would be to allow target specific match.pd patterns to
drive rewriting expressions at the gimple->rtl border.
Jeff
prev parent reply other threads:[~2021-11-23 20:14 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-23 18:34 Navid Rahimi
2021-11-23 19:14 ` Jeff Law
2021-11-23 19:33 ` Andrew Pinski
2021-11-23 19:55 ` [EXTERNAL] " Navid Rahimi
2021-11-23 20:03 ` Jeff Law
2021-11-29 23:51 ` Navid Rahimi
2021-12-03 15:43 ` Jeff Law
2021-11-23 19:42 ` Navid Rahimi
2021-11-23 20:02 ` Jeff Law
2021-11-23 20:08 ` Navid Rahimi
2021-11-23 20:14 ` Jeff Law [this message]
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