A yosys build with verific support can act as a non-verific yosys with
`YOSYS_NOVERIFIC=1` in the enviornment, which is useful for quickly
testing code that works with either frontend without rebuilding yosys.
Before this change, this did not work with `make test` as it would only
consider the build time configuration to decide whether to run tests
that depend on verific support, immediately failing on those tests when
the enviornment contains `YOSYS_NOVERIFIC=1`.
This adds logic to the makefile that checks this enviornment variable
and also exports YOSYS_NOVERIFIC=1 to the enviornment when that is
present as a make variable to support `make test YOSYS_NOVERIFIC=1`
invocations.
Fixes a bug in the handling of the recently introduced $check cells.
Both $check and $print cells in clk2fflogic are handled by the same code
and the existing tests for that were only using $print cells. This
missed a bug where the additional A signal of $check cells that is not
present on $print cells was dropped due to a typo, rendering $check
cells non-functional.
Also updates the tests to explicitly cover both cell types such that
they would have detected the now fixed bug.
Before this commit, `at()` and `operator[]` did the same thing, making
one of them redundant. There was also a somewhat awkward `parts_at()`,
which is more generic than `at()`.
After this commit, `parts_at()` becomes `at()`, and `at()` becomes
`operator[]`. Any quick-and-dirty accesses should use `items["name"]`,
which expects a single-part item. Generic code should instead use
`items.at("name")`, which will return multiple parts. Both will check
for the existence of the name.
This is unlikely to break downstream code since it's likely been using
the shorter `operator[]`. (In any case this API is not stable.)
Because all objects in C++ must have non-zero size, a `value<0>` has
a size of 4 despite consisting of a `uint32_t chunks[0]`. The debug
item assertions were not written expecting that and prevent any debug
items for such values from compiling.
The C API does not define exactly what happens for a zero-width debug
item, but it seems OK to say that they should refer to some unique
pointer that cannot be, in actuality, read or written. This allows
some techniques or optimizations that use `curr` pointers as keys and
assume they correspond 1-to-1 to simulation objects.
The purpose of memtest02 in tests/simple/memory.v is to test bit
select on both memory (mem1) and memory converted to registers (mem2).
After 7cfae2c52, mem1 was automatically converted to registers,
and the test no longer worked as intended. This is fixed by
adding (* nomem2reg *) to mem1.
Checks to see if a cell is of type ff in the liberty,
and keeps track of an additional area value.
```
Chip area for module '\addr': 92.280720
Sequential area for module '\addr': 38.814720
```
Signed-off-by: Ethan Mahintorabi <ethanmoon@google.com>