Word description
A tuple which keeps track of the stacks heights and increments of a basic-block during local analysis. The idea is that if the stack change instructions are tracked, then multiple changes can be folded into one. It has the following slots:
ds-beginDatastack height at the beginning of the block.
rs-beginRetainstack height at the beginning of the block.
ds-incDatastack change during the block.
rs-incRetainstack change during the block.

See also
inc-stack, reset-incs


TUPLE: height-state ds-begin rs-begin ds-inc rs-inc ;