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Re: [MiNT] XaAES sources for FreeMiNT 1.16.3
Vincent Rivière <vincent.riviere@freesbee.fr> writes:
> Andreas Schwab a écrit :
>>> - assembler instructions with no equivalent in C: rol
>>
>> Actually, gcc can generate optimal code for a rotate operation if the
>> expression is written carefully.
>
> Examples welcome.
unsigned int rotate (unsigned int a, int n)
{
return (a << n) | (a >> (sizeof (a) * 8 - n));
}
(It's more difficult for smaller integer types unless the count is
constant.)
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."