Itanium Architecture for Software Developers
This unique description of the Intel Itanium application architecture helps the software development community to use the power of Intel s new line of 64-bit processors.
TABLE OF CONTENTS Itanium Architecture for Software Developers
Chapter 2: Data, Code, and Memory
In the last chapter, you were introduced to the EPIC and its implementation in the Intel Itanium processor the Itanium architecture. The execution environment of this 64-bit architecture consists of the data types, register resources, and memory address space used during the execution of an application program. These elements define the execution state of an application program. The application environment is similar to the execution environment, but it includes only resources that the application programmer can access directly through software. This chapter examines data and code and how they are organized in memory.
DATA TYPES, SIZES, AND FORMATS
Four data types are used to express information, such as integer data and addresses, in the Itanium architecture. Table 2.1 shows the directly supported data types: integer, ordinal, pointer, and immediate. These data types differ according to their use within the architecture. For example, the integer data type is used to express the value of data in a register or storage location in memory, while the immediate data type is used for coding a value as an immediate data into an instruction. On the other hand, the value of a pointer is an address that identifies a storage location in memory. Floating-point data formats are covered in a separate chapter.
| Type/Size | Byte | Word | Double word | Quad word |
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| Integer |
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| Ordinal |
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| Pointer |
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| Immediate |
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The data types are supported in four standard sizes:...
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