linux-kernel - Re: staging: ks7010: Delete unnecessary uses of the variable "retval"

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Message-ID: <c3f1fe70-1270-602c-08ba-b8ba5acbe224@users.sourceforge.net>
Date:	Thu, 21 Jul 2016 14:47:24 +0200
From:	SF Markus Elfring <elfring@...rs.sourceforge.net>
To:	Julia Lawall <julia.lawall@...6.fr>
Cc:	Wolfram Sang <wsa@...-dreams.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	devel@...verdev.osuosl.org, LKML <linux-kernel@...r.kernel.org>,
	kernel-janitors@...r.kernel.org
Subject: Re: staging: ks7010: Delete unnecessary uses of the variable "retval"

> I think the original code was fine.

I suggest to reconsider involved implementation details once more.

> x = blah(); if (x) ... is a perfectly familiar kernel coding pattern.

I can agree to such a general information.

> There is no benefit in terms of performance

It might be possible that a good compiler can also optimise
some unnecessary variable accesses away.

Examples for further background information:
* "Minimize local variables"
   https://eventhelix.com/realtimemantra/basics/optimizingcandcppcode.htm#Minimize%20Local%20Variables

* "Temporary Objects" by Danny Kalev
   http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=198

> or understandability in dropping the variable.

I guess that we have got different opinions on such an aspect.

* Do you really want to assign every return value from a function call
  to an extra variable before it is used again?

* How many reading and understanding capacity do you need for each
  extra variable?

Regards,
Markus