From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <9d2098d3b620d9b101e5045adef3ba4a@hamnavoe.com>
To: 9fans@9fans.net
From: Richard Miller <9fans@hamnavoe.com>
Date: Fri, 20 Sep 2013 10:05:21 +0100
In-Reply-To: <CAOw7k5gR231qkm8AqGFG36BE9GsSn=8CXGqg0V8+Ai5rh1ZG-w@mail.gmail.com>
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Subject: Re: [9fans] comparisons with NaN
Topicbox-Message-UUID: 80c5bdf2-ead8-11e9-9d60-3106f5b1d025

On ARM, it turns out that comparisons with NaN can be made to do the
right thing with no code penalty, by a more careful selection of
condition code values in the subsequent conditional branch.  The
meaning of the CC bits in the PSR is subtly different when they've
been copied from the floating point status register.

Suggested patch is 5c-nan-cmp (works on both vfp and emulated arm7500).