1. A one-sided fudge factor, that is, an
allowance for error but in only one of two directions. For
example, if you need a piece of wire 10 feet long and have to guess
when you cut it, you make very sure to cut it too long, by a large
amount if necessary, rather than too short by even a little bit,
because you can always cut off the slop but you can't paste it back
on again. When discrete quantities are involved, slop is often
introduced to avoid the possibility of being on the losing side of
a fencepost error. 2. The percentage of `extra' code
generated by a compiler over the size of equivalent assembler code
produced by hand-hacking; i.e., the space (or maybe time) you
lose because you didn't do it yourself. This number is often used
as a measure of the goodness of a compiler; slop below 5% is very
good, and 10% is usually acceptable. With modern compiler
technology, esp. on RISC machines, the compiler's slop may
actually be negative; that is, humans may be unable to
generate code as good. This is one of the reasons assembler
programming is no longer common.