When reading from thread space only read the first 32 bits
(sizeof int) for the part select base. This matches the other
parts of the PV_get_base() code.
This patch fixes a problem in the .part/v select when the index is
undefined. The default value needs to be INT_MIN, so when the long
is cast to an int the value is in range.
To get better functionality in V0.9 and development until we
add a select that is sign aware to .part/v this patch uses
a 32 bit integer (int) for the select value. This allows a
normal Verilog integer to produce the correct results. A
warning for smaller signed index vectors is planned, but it
needs more input.
The first input through a net needs to be propagated, since this
is used as an initialization for the net. This patch also cleans
up wires to not need the width_ member, instead inferring the
width from the saved bit value.
Whether and what to propagate after a release of a part needs to
match the behavior of the full-vector release. Nets need to restore
their driver, and regs need to hold their forced value.
filters need to be able to cope with parts of vectors moving through
the net. It makes the most sense to handle every filter as a part-
selected filter.
&PV<> was just using vpi_get_value() when a signal was driving
the select. This incorrectly returned 0 for 'bx or 'bz. This
patch adds a check for an undefined value and returns INT_MIN
for this case.
Now that .net nodes are references to filters into vvp_net_t objects
and are no longer functors on their own, the .alias node becomes
exactly the same as a .net itself.
When releasing a net, the release needs to propagate the driven
value. When releasing a variable, the driven value must be set
to the previously forced value.
These opcodes need to return 'bx or 0.0 for the real opcode when
the array index is undefined.
The patch also documents the auto incrementing of the bit
index register done by the %load/avx.p opcode.
When a part select is driving another part select any bits outside the
original select must be 'bz instead of 'bx. If we initialize the temporary
buffer to 'bz this should work as required. It there are multiple drivers
then a resolver comes into play and this should not matter.
The %shiftr/i0 and %shiftl/i0 opcodes are used for some part
selects and if we have a negative shift we want the value to be
padded with 'bx. This patch enhances the two %shift/i0 opcodes
to work with negative shifts and for negative shifts pad with
'bx instead of 'b0.
It also fixes %ix/get/s to use a uint64_t instead of a unsigned
long to avoid problems with sign extension on 32 bit machines.
Cary R
Stephen Williams