sperber at informatik.uni-tuebingen.de
Thu Sep 20 10:48:45 EDT 2007
Abdulaziz Ghuloum <aghuloum at cs.indiana.edu> writes:
> On Sep 18, 2007, at 11:15 AM, Michael Sperber wrote:
>>> Also, is there a good reason for restricting the range of the second
>>> argument to be less than (fixnum-width)?
>> Well, if that weren't there, you'd get an exception anyway, except for
>> 0, no?
> No actually.
> First, the restriction on the range of the second argument is not
> sufficient to avoid exceptions. (fxarithmetic-shift -72736 17) should
> raise an exception even through |17| < (fixnum-width).
You're right. Still, the restriction is intentional. As Kent pointed
out to me in private email (I hope it's OK I quote this):
>> The ia32 and Sparc architectures ignore all but the low-order 5 bits
>> when shifting 32-bit words. [...] The same would be true on the PowerPC,
>> which ignores all but the low-order 6 bits.
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla
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