why:
the new implementation lost more then 25% execution time on the test
suite when compared to the original VM. so the handler call and the
surrounding statements have been wrapped in a big case statement similar
to the original VM implementation. on Linux/x64, the execution time of
the new VM2 seems to be on par with the old VM.
details:
on Linux/x64, computed goto works and is activated with the -d:release
flag. here the execution time of the new VM2 was tested short of 0.02%
better than the old VM. without the computed goto, it is short of
0.4% slower than the old VM.
why:
activate NIM comments needed re-write. as there is no advantage in using
the macro replacing a few missing op-codes by "Nop##" name symbols, the
macro wrapper has been removed.
details:
when explicitly accessed by numeric value ##, missing Op enum entries
result in a symbol name something like "Op ##".
rather than implicitly using a macro to fix the op-codes list, missing
entries are detected at compile time when a fatal exception is thrown.
the static compile time check verifies that
all op-codes 0 .. 255 are defined
op code name/mnemonic has at least 2 chars and starts with a capital
op code name/mnemonic is not NIM auto-generated (i.e. has a space)
also, original '#' comments are exposed as doc comments '##'