Re: [Linux-ia64] Port of the posix timers to IA64

[Andreas Schwab <schwab@suse.de>]

Eric Piel <Eric.Piel@Bull.Net> writes:

|> Hello David,
|> 
|> I'm working on the port of the posix timers to IA64. The first (over 4)
|> part has just been integrated in the linus tree (2.5.63) so I think you
|> can find interest in my work. 
|> Even if it's supposed to be portable accross platforms, due to some mix
|> between long and int, it doesn't run correctly on IA64. 
|> 
|> Here comes my question, I'm still newbie to kernel hacking and IA64
|> compilation and I don't know how I should handle some troubles with
|> longs. In the code I have some cases like this one:
|> 
|> long v;
|> :
|> :
|> if ( v >= (1 << 56)){
|> :
|> }
|> 
|> It seems very strange for me that when compiling this part gcc considers
|> that eveything must be converted to int. I have to write 1UL instead of
|> 1 in order to obtain the correct behaviour of the code. I guess you've
|> already come along with such problem.

That's how C is working.  A type of an expression is determined
independent of the context, so the type of 1 is always int.  And shifting
by more than the width of the type is an undefined operation.

Andreas.

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Andreas Schwab, SuSE Labs, schwab@suse.de
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