Object Code Accelerator Manual

Introduction
Object Code Accelerator Manual—528144-003
1-2
How the Object Code Accelerator (OCA) Works
Figure 1-2, User Program Execution Modes on TNS/E Systems, on page 1-2 shows
two of the execution modes available to user programs on TNS/E systems: TNS mode
and accelerated mode.
•
TNS mode is the operational environment in which TNS instructions execute. On
TNS/E systems, TNS instructions are implemented by millicode routines.
•
Accelerated mode is the operational environment in which Itanium instructions
generated by OCA execute. On TNS/E systems, Itanium instructions execute
directly on the Itanium processor.
OCA runs on TNS/R and TNS/E systems, and produces the same output in both
environments: a file containing both the original TNS/R code and its Itanium code
equivalent. Accelerated object files can run on both TNS/R and TNS/E systems,
although TNS/R systems ignore the Itanium code.
OCA can process bound, executable object programs generated by B40 and later
releases of the C, COBOL85, FORTRAN, Pascal, and TAL compilers. OCA processes
executable object programs that run only in the Guardian environment. (You cannot
accelerate object programs generated by the COBOL 74 compiler.)
Figure 1-2. User Program Execution Modes on TNS/E Systems
VST0102.vdd
TNS Object File
TNS
Object Code
Accelerated Object File
TNS
Object Code
Accelerated
Object Code
TNS
Instructions
TNS
Instructions
Itanium
Instructions
Itanium
Instructions
Millicode
TNS/E Processor