From: Gary Hook <gary.hook@nimboxx.com>
To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PATCH 1/1] block migration: fix return value mismatch
Date: Thu, 13 Nov 2014 16:44:23 +0000 [thread overview]
Message-ID: <D08A3C06.4232%gary.hook@nimboxx.com> (raw)
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On 11/13/14, 6:46 AM, "Markus Armbruster" <armbru@redhat.com<mailto:armbru@redhat.com>> wrote:
Stefan Hajnoczi <stefanha@gmail.com<mailto:stefanha@gmail.com>> writes:
On Wed, Nov 12, 2014 at 06:48:18PM +0000, Gary Hook wrote:
- return qemu_ftell(f) - last_ftell;
+ delta_ftell = qemu_ftell(f) - last_ftell;
+ return( (delta_ftell > 0) ? 1 : (delta_ftell < 0) ? -1 : 0 );
Good find!
Please don't nest the ternary operator, it is hard to read.
if (delta_ftell < 0) {
return -1;
} else if (delta_ftell > 0) {
return 1;
} else {
return 0;
}
Bah, that's for wimps ;)
return (delta_ftell > 0) - (delta_ftell < 0);
Look ma, no branches!
Ha-ha! Very good, but even less readable than the compressed ternary version,
IMO. This function only gets called once per migration; I don't see a few branches as performance-critical and worth the sacrifice of clarity as to intent.
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next reply other threads:[~2014-11-13 16:44 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-13 16:44 Gary Hook [this message]
2014-11-13 17:03 ` [Qemu-devel] [PATCH 1/1] block migration: fix return value mismatch Eric Blake
2014-11-13 17:32 ` Gary Hook
2014-11-13 18:55 ` Stefan Hajnoczi
2014-11-13 21:12 ` Gary R Hook
-- strict thread matches above, loose matches on Subject: below --
2014-11-21 18:08 Gary R Hook
2014-11-24 9:10 ` Dr. David Alan Gilbert
2014-11-13 16:43 Gary Hook
2014-11-12 18:48 Gary Hook
2014-11-12 20:27 ` Eric Blake
2014-11-13 7:57 ` Markus Armbruster
2014-11-13 11:20 ` Stefan Hajnoczi
2014-11-13 12:46 ` Markus Armbruster
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