From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Mon, 21 Nov 2011 07:33:26 -0800
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From: Charles Forsyth <charles.forsyth@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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Subject: Re: [9fans] sysrfork fp bug?
Topicbox-Message-UUID: 422aa43c-ead7-11e9-9d60-3106f5b1d025

registers are dead on entry to a function, so there's no point in saving
particular values, because they won't be used. on an amd64, however,
the kernel should
reset the FP-used flag, to cause the preset values to be set in the high FP
registers if the fork'd process does touch the FP.

On 21 November 2011 07:08, erik quanstrom <quanstro@quanstro.net> wrote:
> sysrfork() does *not* do a procsave before forking. =C2=A0thus the
> floating point registers in the new process are just going to
> be a copy of whatever was last saved, and perhaps nothing.