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Re: Short float arrays
- To: Jim Hurd <71501.1347@CompuServe.COM>
- Subject: Re: Short float arrays
- From: bill@cambridge.apple.com (Bill St. Clair)
- Date: Mon, 17 Aug 1992 18:03:27 -0500
- Cc: info-mcl
>>Not necessary. Since SHORT-FLOAT's are immediate objects, storing
>>them in an array with an element-type of T is as good as anything.
>
>Wouldn't arrays of short-floats eliminate some masking of the tag bits?
If MCL's compiler did floating point optimizations (which it doesn't), then
a SHORT-FLOAT array element type would be useful. Your declaration of the
array's type would sometimes allow the compiler to generate better code.
Since the compiler doesn't optimize floating point computations,
a SHORT-FLOAT array element type would actually slow things down.
It would require AREF to translate from array storage format to
immediate short-float format rather than just returning the bits
as they're stored in the array.