X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:reply-to:message-id
	:references:in-reply-to:mime-version:content-type
	:content-transfer-encoding; q=dns; s=default; b=cbZILUtDfCKptHlo
	WTfjdB3hPdoNKXIso6gllgkyNzFFNBmmu6w/Z+CJddXCYOEcyv4afBDd0HoofNOt
	wRUmkGZLttztpxYaVBIq0VcYnlslMM4phEyUOaSBMfiJuc4E6xvf/yhIGOIPFUeE
	5n8lmjxU16N0micYUstxO9Iralg=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:from:to:subject:date:reply-to:message-id
	:references:in-reply-to:mime-version:content-type
	:content-transfer-encoding; s=default; bh=0/GXaPcp1KwUff/FIVLpRl
	iBgdk=; b=sljg7Q4vDLoIg+H4/Dr2ner4l/iRGN29xQRAssFlkFH2I+8rXNfRn3
	OokmvIo6CDdi8xfd4K8riBANqs726UddhtoPdXvyqGbRz5Qxe8YYFeuvYX1Y7Ify
	/c/zCwWqMtkhW55ZlbZ8mK7TF+mxMfoeVr/yx5bFyMAkjzmsjSZ6U=
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-1.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2
X-HELO:	homiemail-a109.g.dreamhost.com
From:	Bengt Larsson <lists DOT cygwin4 AT bengtl DOT net>
To:	cygwin AT cygwin DOT com
Subject:	Re: Performance problem with gcc 4.9.2-3 on 64 bit
Date:	Sat, 28 Feb 2015 18:56:39 +0100
Reply-To:	cygwin AT cygwin DOT com
Message-ID:	<snv3fa59ju0iespsctf8rknbk6feqc3t25@4ax.com>
References:	<cm61fadkltbqshdmtiil4nb50b0gf1n3qg AT 4ax DOT com> <54F13EA8 DOT 9060609 AT gmail DOT com>
In-Reply-To:	<54F13EA8.9060609@gmail.com>
User-Agent:	ForteAgent/7.20.32.1218
MIME-Version:	1.0
X-IsSubscribed:	yes

Marco Atzeri wrote:
>On 2/27/2015 5:49 PM, Bengt Larsson wrote:
>> Below are two benchmarks that explore maximum floating point
>> performance. loopm6 is double precision floating point and loopm6fp is
>> parallell single-precision. They are manually unrolled multiply-add
>> loops.
>>
>> I used to reach 2.8 and 11 GFlops on these. Now I only get
>> 2 and 6.
>>
>> If you explore the inner loop with gcc -O2 -S you can see that it seems
>> to use few registers.
>>
>> If you run them, there is a parameter expected. I use 30000 - 50000.
>>
>> gcc 4.9.2-3 on 64-bit. I use gcc -O2.
>>
>
>May be
>https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53967

I think that was longer ago. On the version before 4.9.* on Cygwin I got
full speed. 

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -