CHEAP - steal space from linkage area.

Usage:

cheap  symbol

Examples:

cheap  unit
cheap  tally

Where:

symbol

is any valid GMAP symbol. It will be defined as a stack offset into the linkage area for the called function.

Description:

Simple functions that do not advance the stack can make use of the linkage space of the calling routine to store two local variables. There are only two of these words available, so the CHEAP macro can only be used twice. Its use conflicts with the use of SENTRY or ADVNCE.

Approximate equivalent code generated:

*      cheap   tally
tally  set     S.RET
*      cheap   second
second set     S.PREV

See Also:

expl b bmac bentry

for function entry with no stack advance

Copyright © 1996, Thinkage Ltd.