Log Message:
update to verilog-current-20020828

Release Notes for Snapshot 20020828

This snapshot adds support for parameter and localparam bit
ranges. This is a IEEE1364-2001 feature, although some -1995 compilers
have supported it in the past.

Fixed a *nasty* and slippery bug with the evaluation of bit select of
nets. (Bit select of variables was unaffected.) The symptoms did not
clearly point to the problem, so bugs related to it were often mis-
reported.

Gate delays were lost when constants were propagated to their
inputs. This is fixed for the known broken cases. Also, mux output
delays have been fixed. Also, release statements that apply to elided
nets are turned into no-ops.

The r-values of non-blocking assignments are now precalculated at
compile time, if possible, as is done with blocking assignments. This
speeds up constant propagation, and is more thorough.

Also optimize subtraction of small constants from vectors, with the
new %subi instruction in vvp. This saves some in code size and thread
footprint.

Handling of x in r-value bit selects and memory word selects did the
wrong thing. Now they do the right thing. Also, x in the selector of
?: ternary operators does the right (and complicated) thing now. In
the process, a fork-join code generator bug was fixed.

Several bugs with time formatting have been fixed.

Temporaries in sequential blocks are detected by the synthesizer, and
converted into wires when needed. This expands support for
combinational logic synthesis.