From mboxrd@z Thu Jan  1 00:00:00 1970
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: Re: [PATCH v3 07/13] x86: Add functions for 64-bit
	integer arithmetic
Date: Mon, 4 Jan 2016 13:26:52 -0500
Message-ID: <568AB96C.9010008@oracle.com>
References: <1451531020-29964-1-git-send-email-haozhong.zhang@intel.com>
	<1451531020-29964-8-git-send-email-haozhong.zhang@intel.com>
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To: Haozhong Zhang <haozhong.zhang@intel.com>, xen-devel@lists.xen.org, Jan Beulich <jbeulich@suse.com>, Kevin Tian <kevin.tian@intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>, Andrew Cooper <andrew.cooper3@citrix.com>, Keir Fraser <keir@xen.org>, Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>, Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
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On 12/30/2015 10:03 PM, Haozhong Zhang wrote:
> This patch adds several functions to take multiplication, division and
> shifting involving 64-bit integers. Those functions are derived from
> Linux kernel and will be used by later patches to calculate scaling
> ratio and scaled TSC.
>
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(although I not sure why you decided to change Linux' code in mul64() below)



> +    c = (u64)rl.l.high + rm.l.low + rn.l.low;
> +    rl.l.high = c;
> +    c >>= 32;
> +    c = c + rm.l.high + rn.l.high + rh.l.low;
> +    rh.l.low = c;
> +    rh.l.high += (u32)(c >> 32);