From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Liu Yu <Yu.Liu@freescale.com>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] Fix remainder calculating bug in single floating point division
Date: Mon, 07 Jan 2008 07:07:45 +1100 [thread overview]
Message-ID: <1199650065.7291.81.camel@pasglop> (raw)
In-Reply-To: <11996296134110-git-send-email-Yu.Liu@freescale.com>
On Sun, 2008-01-06 at 22:26 +0800, Liu Yu wrote:
> This bug exists in the emulation of floating point division for powerpc.
>
> The original code cannot count the remainder correctly.
> I can provide a test case to trigger this bug.
> When use fdiv to count 1.1754941e-38f / 0.9999999f,
> the result is expected to be 1.175494e-38f,
> but we will get 1.174921e-38f in the original case.
It's nice to see somebody digging in that scary math emu stuff. If you
could also get rid of the warnings, it would be perfect :-)
Now, appart from that, I seem to remember Dan telling me at some point
in the past (I think it was Dan... ) that this code was lifted from
somewhere else (glibc ? gcc soft-float ?), in which case it might be
worth to fix that somewhere else as well, or if it's already been fixed,
maybe resync.
Cheers,
Ben.
next prev parent reply other threads:[~2008-01-06 20:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-06 14:26 [PATCH] Fix remainder calculating bug in single floating point division Liu Yu
2008-01-06 20:07 ` Benjamin Herrenschmidt [this message]
2008-01-06 20:44 ` Dan Malek
2008-01-06 20:49 ` Benjamin Herrenschmidt
2008-01-07 1:09 ` Josh Boyer
2008-01-08 6:20 ` Kumar Gala
2008-01-09 15:38 ` [PATCH] Fix remainder calculating bug in single floating pointdivision Liu Yu
2008-01-09 16:19 ` Kumar Gala
2008-01-08 6:22 ` [PATCH] Fix remainder calculating bug in single floating point division Kumar Gala
2008-01-09 1:24 ` Liu Yu
2008-01-09 23:48 ` David Gibson
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