Log Library - How is it done in the library code?
Henry Spencer
henry at zoo.toronto.edu
Thu Mar 14 02:38:41 AEST 1991
In article <1991Mar12.211047.826 at m.cs.uiuc.edu> joshi at m.cs.uiuc.edu (Anil Joshi) writes:
>All I needed was the info as to what is being done in the library
>routine so that I can emulate the library routine. ... why I asked
>whether the code is available somewhere, so that I can make my
>program efficient and fast.
Unfortunately, you didn't really supply enough information for this.
There is no single source for the log function; the answer is vendor-
specific. As a particular case in point, on a 68xxx machine with a
68881, the best log routine consists of (ignoring calling-sequence
overhead):
FLOGN r1, r2
or the equivalent. That's right, one instruction. On most more modern
machines the sequence will be more complex. :-) When you post such
queries, you need to supply details on things like machine, compiler,
and requirements.
--
"But this *is* the simplified version | Henry Spencer @ U of Toronto Zoology
for the general public." -S. Harris | henry at zoo.toronto.edu utzoo!henry
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