HP aC++/HP C A.06.25 Programmer's Guide

data_model can be one of the following:
• 32 (This value generates ILP32 code and is the default.)
• 64 (This value generates LP64 code.)
This option specifies the data model for the compiler. Table 2-1 lists the differences
between the two data models.
Table 2-1 ILP32 Data Model and LP64 Data Model
LP64 Data ModelILP32 Data Model
The size of an int data type is 32-bits. The size of a
long or pointer data type is 64-bits.
The size of an int, long, or pointer data type is
32-bits.
The preprocessor predefined macros__LP64__ and
_LP64 are defined.
The preprocessor predefined macro _ILP32 is
defined.
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.
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
Options to Control Code Generation 41