Raymond Toy (RT/EUS) writes: > >>>>> "WP" == Walter C Pelissero <[EMAIL PROTECTED]> writes: > > WP> Raymond Toy (RT/EUS) writes: > >> Thanks for the replacement. The only possible issue with the > >> replacement would be performance. BIT-BASH-COPY tries pretty hard > >> to do word copies. And BIT-BASH-COPY is intended to be able to > >> copy arbitrary bit strings. I don't know why it's limited to > >> (unsigned-byte 27) offsets. Perhaps to make sure the bit index > >> stays as a 32-bit int? > > WP> This is what came to mind reading the error. What I didn't > understand > WP> is why we get an error at all, being: > > WP> 2^27 > 17M (way larger) > > But the 17M is converted to a bit index and the bit index is greater > than 2^27.
Sorry, I failed to grasp the meaning of the "bit-" part. > As an experiment, I changed the constant max-bits in > code/bit-bash.lisp from 2^27 to most-positive-fixnum. The comment > there says it's the maximum number of bits that can be delt [sic] with > during a single call. I suppose one could compare the generated code (disassembling it) and see if there is any degradation. > I don't see why it can't really handle at least > most-positive-fixnum number of bits or even #xffffffff number of > bits. [I assume you meant 2^32 and not 2^2^32] Wouldn't a 32-bit integer be too big to fit in a "simple" Lisp object thus requiring a further indirection? -- walter pelissero http://www.pelissero.de
