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System V UNIX ABI (Application Binary Interface); see:
http://www.linuxbase.org/spec/refspecs/elf/gabi4+/contents.html
4.4.1 Linux IA-64 kernel overview
The following information is helpful if you plan to recompile or port some software
to IA-64 kernel. The main objective of this section is to introduce some basic
concepts about the Linux kernel and the most important differences between the
IA-32 version and the new 64-bit IPF (Itanium Processor Family, or IA-64)
architecture. Your preferred Linux distribution may have done this recompilation
for you, but it is very common to recompile software under Linux, for example, if
you get only the source code and not an installable package.
Data types
In 1996, The Open Group decided to extend the
64-bit Systems
Linux kernel developers attempt to follow the Open Group standards as much as
possible, so the Linux IA-64 kernel uses the LP64 Data Model, as defined by The
Open Group. This data model is LP64 because it allows long and integer types
up to 64 bits. 32-bit Intel processors use the LP32 Data Model. This model is an
industry standard and it is used in all other 64-bit Linux and UNIX
implementations.
Some of the usual data types on C change between the LP64 and the LP32 Data
Models, as shown in Table 4-4.
Table 4-4 Comparison table of C types between LP32 and LP64
Data type in C
char
short
int
long
long long
pointer
enum
float
double
IBM Eserver xSeries 455 Planning and Installation Guide
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to create a new standard on 64-bit for any UNIX operating system.
LP32
8
16
32
32
64
32
32
32
64
Single UNIX Specification for
LP64
8
16
32
64
64
64
32
32
64
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