User's Guide

Examples:
The following command generates code for the 64-bit data model:
aCC +DD64 app.C
The following command generates code for the 32-bit data model:
aCC app.C
+DSmodel
The +DSmodel option performs instruction scheduling for a particular implementation of the
Itanium®-based architecture.
model can be one of the following values.
blended Tune to run reasonably well on multiple implementations. As old implementation
become less important and new implementations are added, the behavior with
this value will change accordingly.
itanium
Tune for the Itanium® processor.
itanium2
Tune for the Itanium2® processor.
mckinley
See itanium2® .
montecito
Tune for the Montecito® processor.
poulson
Tune for the Poulson® processor.
native Tune for the processor on which the compiler is running.
The default is blended. Object code with scheduling tuned for a particular model will execute on
other HP-UX systems, although possibly less efficiently.
Using +DS to Specify Instruction Scheduling
Instruction scheduling is different on different implementations of Itanium®-based architectures.
You can improve performance on a particular model or processor of the HP-UX system by requesting
the compiler to use instruction scheduling tuned to that particular model or processor. Using
scheduling for one model or processor does not prevent your program from executing on another
model or processor.
If you plan to run your program on the same system where you are compiling, you do not need
to use the +DS option. The compiler generates code tuned for your system.
If you plan to run your program on a particular model of the HP-UX system, and that model is
different from the one where you compile your program, use +DSmodel with either the model
number of the target system or the processor name of the target system.
Compiling in Networked Environments
When compiles are performed using diskless workstations or NFS-mounted file systems, it is
important that the default code generation and scheduling are based on the local host processor.
The system model numbers of the hosts where the source or object files reside do not affect the
default code generation and scheduling.
-S
The -S option compiles a program and logs the assembly language output in a corresponding file
with a .s suffix. The -S option is only for displaying the assembler code. The generated code is
not intended to be used as input to the assembler (as).
Example:
Options to Control Code Generation 33