From: Richard Miller <9fans@hamnavoe.com>
To: 9fans@9fans.net
Subject: Re: [9fans] comparisons with NaN
Date: Fri, 20 Sep 2013 10:05:21 +0100 [thread overview]
Message-ID: <9d2098d3b620d9b101e5045adef3ba4a@hamnavoe.com> (raw)
In-Reply-To: <CAOw7k5gR231qkm8AqGFG36BE9GsSn=8CXGqg0V8+Ai5rh1ZG-w@mail.gmail.com>
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).
next prev parent reply other threads:[~2013-09-20 9:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-21 13:17 Richard Miller
2013-08-21 14:34 ` erik quanstrom
2013-08-21 16:08 ` Richard Miller
2013-08-21 16:55 ` erik quanstrom
2013-08-21 17:42 ` Bakul Shah
2013-08-21 17:47 ` erik quanstrom
2013-08-21 18:00 ` Bakul Shah
2013-08-21 18:00 ` Richard Miller
2013-08-21 18:24 ` Charles Forsyth
2013-08-22 14:05 ` Richard Miller
2013-08-22 14:25 ` Charles Forsyth
2013-09-20 9:05 ` Richard Miller [this message]
2013-08-21 14:36 ` erik quanstrom
2013-08-21 18:24 ` lucio
2013-08-21 18:27 ` erik quanstrom
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