10 Sep
2001
10 Sep
'01
9:20 p.m.
Thanks. I think the decision here is to do the safe thing and mask the return results ourselves, since it's only one extra insn. This won't make it into 5.02, tho.
So GHC's Int/Word implementation is different from Hugs'? Hugs represents Word8 (say) by a 32 bit int but doesn't guarantee that the top 24 bits are all zero. Instead we either use an 8-bit operation when we operate on a word8 or we mask the arguments and use the 32-bit operation (for *, /, ==, etc.) or we don't mask and use the 32-bit operation (works for and, or, +, and some of the shifts) -- Alastair Reid reid@cs.utah.edu http://www.cs.utah.edu/~reid/