Before this patch, the code passed around std::string objects by
value. It's probably not a hot-spot, but it can't hurt to avoid the
copying.
Removing the copy and clean-up code means the resulting code is ~6.1kb
smaller when compiled with GCC 9.3 and standard settings.
- Pass a string argument by reference
- Avoid multiple calls to IdString::str and IdString::c_str
- Avoid combining checks for size > 0 and first char (C strings are
null terminated, so foo[0] != '\0' implies that foo has positive
length)
With GCC 9.3, at least, compiling select.cc spits out a warning about
an implausible bound being passed to strncmp. This comes from inlining
IdString::compare(): it turns out that passing std::string::npos as a
bound to strncmp triggers it.
This patch replaces the compare call with a memcmp with the same
effect. The repeated calls to IdString::c_str are slightly
inefficient, but I'll address that in a follow-up commit.
This code originally comes from commit 458a940. When an interface is
used via a modport, code in genrtlil.cc sets '\\interface_type' and
'\\interface_modport' properties on the wire.
In hierarchy.cc, we pick up the modport name and add it to a dict
called modports_used_in_submodule (that maps connection source to
modport name).
Before this patch, the modport name is retrieved as a strpool and then
iterated over in an arbitrary order, discarding all entries but the
last. In practice, the pool will always have 0 or 1 entries because
the string used to construct it is a valid identifier, so doesn't
contain any pipe symbols.
This patch changes the code to retrieve the modport name as just a
string. This will have the same effect in practice, but may be a bit
less confusing!
The code also gets moved down closer to where the result is used,
which might be a bit more efficient since we won't always get as far
as the check.
The patch also removes some commented-out code, which I think was
intended to add some typechecking at some point, but was never
implemented. Since this dates back to October 2018, I think it makes
more sense to just take it out.
Ensures that "BV" is the logic whenever solving an exists-forall problem with Yices, moves the "(set-logic ...)" directive above any non-info line, sets the `ef-max-iters` parameter to a very high number when using Yices in exists-forall mode so as not to prematurely abandon difficult problems, and does not provide the incompatible "--incremental" Yices argument when in exists-forall mode.
