HP 3000 Manuals HP 3000 Manuals
Shifting Data from the Data Area to the Stack Area Another improvement in performance can be gained by shifting data from the data area to the stack area. In general, accessing data from the stack or code area takes one machine instruction, while accessing data from the data area requires two instructions. To shift data, use assignment statements if you do not require the data values to remain the same across routines. Shifting data eliminates initializing data with DATA statements. Then, instead of routines communicating through common blocks, you can use parameters. Shifting data from the data to the stack area also produces more opportunities for the optimizer to allocate register variables, and thereby improving optimization.