MEDIUM: samples: provide basic arithmetic and bitwise operators
This commit introduces a new category of converters. They are bitwise and
arithmetic operators which support performing basic operations on integers.
Some bitwise operations are supported (and, or, xor, cpl) and some arithmetic
operations are supported (add, sub, mul, div, mod, neg). Some comparators
are provided (odd, even, not, bool) which make it possible to report a match
without having to write an ACL.
The detailed list of new operators as they appear in the doc is :
add(<value>)
Adds <value> to the input value of type unsigned integer, and returns the
result as an unsigned integer.
and(<value>)
Performs a bitwise "AND" between <value> and the input value of type unsigned
integer, and returns the result as an unsigned integer.
bool
Returns a boolean TRUE if the input value of type unsigned integer is
non-null, otherwise returns FALSE. Used in conjunction with and(), it can be
used to report true/false for bit testing on input values (eg: verify the
presence of a flag).
cpl
Takes the input value of type unsigned integer, applies a twos-complement
(flips all bits) and returns the result as an unsigned integer.
div(<value>)
Divides the input value of type unsigned integer by <value>, and returns the
result as an unsigned integer. If <value> is null, the largest unsigned
integer is returned (typically 2^32-1).
even
Returns a boolean TRUE if the input value of type unsigned integer is even
otherwise returns FALSE. It is functionally equivalent to "not,and(1),bool".
mod(<value>)
Divides the input value of type unsigned integer by <value>, and returns the
remainder as an unsigned integer. If <value> is null, then zero is returned.
mul(<value>)
Multiplies the input value of type unsigned integer by <value>, and returns
the product as an unsigned integer. In case of overflow, the higher bits are
lost, leading to seemingly strange values.
neg
Takes the input value of type unsigned integer, computes the opposite value,
and returns the remainder as an unsigned integer. 0 is identity. This
operator is provided for reversed subtracts : in order to subtract the input
from a constant, simply perform a "neg,add(value)".
not
Returns a boolean FALSE if the input value of type unsigned integer is
non-null, otherwise returns TRUE. Used in conjunction with and(), it can be
used to report true/false for bit testing on input values (eg: verify the
absence of a flag).
odd
Returns a boolean TRUE if the input value of type unsigned integer is odd
otherwise returns FALSE. It is functionally equivalent to "and(1),bool".
or(<value>)
Performs a bitwise "OR" between <value> and the input value of type unsigned
integer, and returns the result as an unsigned integer.
sub(<value>)
Subtracts <value> from the input value of type unsigned integer, and returns
the result as an unsigned integer. Note: in order to subtract the input from
a constant, simply perform a "neg,add(value)".
xor(<value>)
Performs a bitwise "XOR" (exclusive OR) between <value> and the input value
of type unsigned integer, and returns the result as an unsigned integer.
2 files changed