This patch adds the constant system functions for Verilog-2005
and Verilog-AMS. These are evaluated at compile time. $abs(),
$min() and $max() support their polymorphic behavior in the
compiler where it really matters. They are always evaluated
as reals in the run time and the result/argument(s) will be
converted as needed.
The Verilog-2005 functions are available if using the 2005
generation (default) and if either the icarus-misc (also on
by default) or verilog-ams flags are set.
The Verilog-AMS functions are available if either the
icarus-misc or verilog-ams flags are set.
This patch adds the $clog2 system function. It also makes this
function work as a constant function. The runtime version still
needs to be updated to use an integer based version instead of
the current double based method. The double method suffers from
rounding errors.
Stephen Williams
Cary R