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From: Marek Polacek <polacek@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Biener <rguenther@suse.de>, Jeff Law <law@redhat.com>,
	Wilco Dijkstra <Wilco.Dijkstra@arm.com>,
	gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Improve pow (C, x) -> exp (log (C) * x) optimization (PR middle-end/84309)
Date: Sat, 10 Feb 2018 12:29:00 -0000	[thread overview]
Message-ID: <20180210122913.GL2608@redhat.com> (raw)
In-Reply-To: <20180209233738.GQ5867@tucnak>

On Sat, Feb 10, 2018 at 12:37:38AM +0100, Jakub Jelinek wrote:
> Hi!
> 
> Apparently the new pow(C,x) -> exp(log(C)*x) if C > 0 optimization
> breaks some package (Marek should know which), as it has 7ulp error.
> Generally one should be prepared for some errors with -ffast-math.

I reduced it from "test-cachunker" in package casync.

	Marek

      parent reply	other threads:[~2018-02-10 12:29 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-09 23:49 Jakub Jelinek
2018-02-10  7:00 ` Richard Biener
2018-02-10  9:49   ` Jakub Jelinek
2018-02-10 11:29     ` Richard Biener
2018-02-10 17:49       ` Jakub Jelinek
2018-02-10 16:04         ` Richard Biener
2018-02-12 21:47         ` [PATCH] Improve pow (C, x) -> exp (log (C) * x) optimization (PR middle-end/84309, take 2) Jakub Jelinek
2018-02-13  7:59           ` Richard Biener
     [not found]     ` <DB6PR0801MB20531E5198E7A00B03443EB783F10@DB6PR0801MB2053.eurprd08.prod.outlook.com>
2018-02-12 22:01       ` [PATCH] Improve pow (C, x) -> exp (log (C) * x) optimization (PR middle-end/84309) Joseph Myers
2018-02-10 12:29 ` Marek Polacek [this message]

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