Solaris 64-bit Developer's Guide


The capabilities of the SolarisTM operating environment continue to expand to meet customer needs. The Solaris operating environment was designed to fully support both the 32-bit and 64-bit architectures. The Solaris operating environment provides an environment for building and running 64-bit applications that can use large files and large virtual address spaces. At the same time, the Solaris operating environment continues to provide maximum source compatibility, maximum binary compatibility, and interoperability for 32-bit applications. In fact, most of the system commands that run and have been built on the Solaris 64-bit implementation are 32-bit programs.

Note –

This Solaris release supports systems that use the SPARC® and x86 families of processor architectures: UltraSPARC®, SPARC64, AMD64, Pentium, and Xeon EM64T. The supported systems appear in the Solaris 10 Hardware Compatibility List at This document cites any implementation differences between the platform types.

In this document the term “x86” refers to 64-bit and 32-bit systems manufactured using processors compatible with the AMD64 or Intel Xeon/Pentium product families. For supported systems, see the Solaris 10 Hardware Compatibility List.

The major differences between the 32-bit and the 64-bit application development environments are that 32-bit applications are based on the ILP32 data model, where ints, longs, and pointers are 32 bits, while 64-bit applications are based on the LP64 model, where longs and pointers are 64 bits and the other fundamental types are the same as in ILP32.

Most applications can remain as 32-bit programs with no changes required. Conversion is necessary only if the application has one or more of the following requirements:

Specific interoperability issues can also require code changes. For example, if your application uses files that are larger than 2 gigabytes, you might want to convert the application to 64-bit.

In some cases, you might want to convert applications to 64-bit for performance reasons. For example, you might need the 64-bit registers to do efficient 64-bit arithmetic or you might want to take advantage of other performance improvements that a 64–bit instruction set provides.

Who Should Use This Book

This document is written for C and C++ developers and provides guidance on how to determine whether an application is 32-bit or 64-bit. This document provides

How This Book Is Organized

This book is organized into the following chapters.

Related Books

For further reading, the following texts are recommended:

Accessing Sun Documentation Online

The docs.sun.comSM Web site enables you to access Sun technical documentation online. You can browse the archive or search for a specific book title or subject. The URL is

What Typographic Conventions Mean

The following table describes the typographic changes that are used in this book.

Table P–1 Typographic Conventions

Typeface or Symbol 




The names of commands, files, and directories; on-screen computer output 

Edit your .login file.

Use ls -ato list all files.

machine_name% you have mail.


What you type, contrasted with on-screen computer output 

machine_name% su Password:


Command-line placeholder: replace with a real name or value 

To delete a file, type rm filename.


Book titles, new words or new terms, or words to be emphasized. 

Read Chapter 6 in User's Guide.

These are called class options.

Do not save changes yet.

Shell Prompts in Command Examples

The following table shows the default system prompt and superuser prompt for the C shell, Bourne shell, and Korn shell.

Table P–2 Shell Prompts



C shell prompt 


C shell superuser prompt 


Bourne shell and Korn shell prompt 


Bourne shell and Korn shell superuser prompt 


Note –

The term “IA-32” refers to the Intel 32–bit processor architecture. This architecture includes the Pentium, Pentium Pro, Pentium II, Pentium II Xeon, and Pentium III processors and compatible microprocessor chips made by AMD and Cyrix.