warning question

[Arnout Vandecappelle]

On Wednesday 06 May 2009 17:49:28 Joel Sherrill wrote:
> Hi,
>
> I am looking at warnings and wondered if someone
> could figured this one out.
>
> c/src/libchip/network/i82586.c:1722: warning: suggest parentheses around
> operand of '!' or change '|' to '||' or '!' to '~'
>
> The code is clearly questionable IMO. ;)
>
>   *IE_CMD_CFG_PROMISC(buf)   = !!promiscuous | manchester << 2;

 This means (!!promiscuous) | (manchester << 2).  It looks OK to me, though 
adding parenthases around as I did certainly makes things clearer.

 The !! is a trick to make sure you have a 1, not just any non-zero int.

 Regards,
 Arnout
-- 
Arnout Vandecappelle                               arnout at mind be
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