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This is a C++ program to look for candidate superoperators, make a perfect
hash function for them, and write out the tables needed and the perfect
hash functions.
Much of the code in this directory is taken from GPERF, as a result,
it is written in a different style than superops.cc which is the main
driver program (e.g. superops.cc uses the STL, many other files do not).
The reason why I used GPERF's code instead of using GPERF directly
(as I do for the builtins.gperf hash function, for example) is that:
1) I would still have needed to write code to glue the
superoperator search with GPERF.
2) I needed a completely different calling convention and
implementation of the lookup function than the usual one: so instead
of hacking and sed'ing GPERF's output I decided that modifying
GPERF's output routines would have been more maintainable.
3) I had already written the superoperator search program in C++, which
made it easier to put in GPERF's code.
4) It is unlikely that GPERF changes significantly enough (and that
superops be ever used again to generate a new bytecode set) to
consider merging the upstream modifications into superops.
The GPERF code was taken almost unmodified with the exception of
options.cc (because most options that only affected output are not
needed anymore, and because I stripped the getopt code). Of course,
input.cc and main.cc are not there anymore, their function is done by
the single file hash.cc, which also includes much of output.cc.
Run the program, and it will automagically generate:
1) superop1.inl and superop2.inl, which contain the hash
tables and the tables for writing the hash lookup function.
2) byte.def, the final part of the input to genbc (used for
decoding the instructions).
3) vm.def, the final part of the input to genvm (used for
executing the instructions in the virtual machine proper).
4) table.st, the superoperator table to be included in
CompildCode.st.
This is strictly a maintainer tool, so it is written for a recent
C++ compiler and does not even use autoconf.
Paolo
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