-*- Mode:Text -*-

The "virtual" instruction set fields total greater than 64 bits.  Most
of the combinations of fields that use each bit field for only one
purpose are legitimate, but because there are so many possible
combinations of fields, the set of legitimate instructions is not
clearly expressible.

The compiler can most naturally output a stream of instructions in one
of two forms.

One way is to output the instructions with all fields filled in, and
then split apart some instructions with conflicting fields.  This may be
the most natural way to generate code, but may result in code that is
less dense than if the instructions are explicitly packed.

The other way is to output a stream of dissociated fields in the order
in which they are executed, and to pack them afterwards.