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Date: Sat, 3 Mar 2018 22:49:13 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: Ian Lepore <ian@freebsd.org>
Cc: Hans Petter Selasky <hselasky@FreeBSD.org>, src-committers@freebsd.org,
 svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject: Re: svn commit: r330352 - in head/sys/compat/linuxkpi/common:
 include/linux src
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On Sat, Mar 03, 2018 at 12:14:42PM -0700, Ian Lepore wrote:
> To really avoid roundoff errors, use mstosbt(ms) instead of SBT_1MS*ms.
> 
> The rounding errors when multiplying or dividing by SBT_1MS is not
> severe like it is with SBT_1NS, but the inline functions still do the
> arithmetic more correctly to avoid roundoff error.

BTW mstosbt() and other functions have weird bracing in the formula. I
think that the formula as calculated by the C operator precedence is
fine, i.e. multiplication is done before right shift. But the bracing
is redundand then, because the '()' pair next to the return () braces by
inclusion is tautological.