Currently vvp only applies the pullup/pulldown for tri1/tri0 nets when
the net is not driven. The correct behaviour is to treat the pullup/
pulldown as an extra driver (with pull strength).
For synthesis we remove the output set of signals from the input set to
remove temporaries from the final sensitivity set. The @* construct also
uses the input sensitivity list, but because it can include statements
that cannot be synthesized we should not calculate the output set for this
case. Not find the output set is also a speed enhancement since the output
set was already being ignored later in the code for this case.
To be strictly compliant with the standard and compatible with other
EDA tools, unsized numbers should be treated as having a fixed size
(the same size as an integer). The -gstrict-expr-width option is
extended to allow the user to enable this behaviour.
This option is intended to make it easier to compare results from
Icarus with results from other simulators. For now, the only effect
it has is to change the default format for displaying real numbers
when no format string is supplied.
This includes adding support for returning strings from functions,
adding initializing new darray with array_pattern strings, and
assigning an array_pattern of strings to a preallocated darray.
Also fix up support for initializing array with simple string
expression.
When you have an expression like this (extreme example):
a[idx[1]][idx[2]*4 +: 4] <= #(idx[3]) 4'ha;
where a is a reg array and idx is a reg or net array. The retrieval
of idx[2] was clobbering index register 3, which was set before
evaluating the part offset expression, then used in the %set/av of the
array value. (likewise for idx[1] and idx[3]])
To avoid this issue, this patch adds and uses a new instruction
%ix/mov which simply copies one indexed register to another. When
necessary, expressions are first evaluated into temporary registers to
avoid clobbering, then moved in to place before the %*/av instruction.
Implements page 644 of IEEE 1800-2012.
`` is now overloaded with the Icarus-specific "stringify" expansions.
It is now used as indicated in 1800-2012 when appearing inside a macro
definition, and the Icarus way when not. To do so, it uses the fact
that istack->file is NULL iff we are processing expanded macro text,
which is a bit of hack but works as is.
`" and `\`" on the other hand are treated the same inside and outside
of macro definitions.
Martin Whitaker
Cary R
Stephen Williams
Jared Casper