Intel® 64 and IA-32 Architectures Optimization Reference Manual

CHAPTER 1INTRODUCTIONThe Intel® 64 and IA-32 Architectures Optimization Reference Manual describes howto optimize software to take advantage of the performance characteristics of IA-32and Intel 64 architecture processors. Optimizations described in this manual apply toprocessors based on the Intel ® Core microarchitecture, Intel NetBurst ® microarchitecture,the Intel ® Core Duo, Intel Core Solo, Pentium ® M processor families.The target audience for this manual includes software programmers and compilerwriters. This manual assumes that the reader is familiar with the basics of the IA-32architecture and has access to the Intel® 64 and IA-32 Architectures Software Developer’sManual (five volumes). A detailed understanding of Intel 64 and IA-32 processorsis often required. In many cases, knowledge of the underlying microarchitecturesis required.The design guidelines that are discussed in this manual for developing highperformancesoftware generally apply to current as well as to future IA-32 andIntel 64 processors. The coding rules and code optimization techniques listed targetthe Intel Core microarchitecture, the Intel NetBurst microarchitecture and thePentium M processor microarchitecture. In most cases, coding rules apply to softwarerunning in 64-bit mode of Intel 64 architecture, compatibility mode of Intel 64architecture, and IA-32 modes (IA-32 modes are supported in IA-32 and Intel 64architectures). Coding rules specific to 64-bit modes are noted separately.1.1 TUNING YOUR APPLICATIONTuning an application for high performance on any Intel 64 or IA-32 processorrequires understanding and basic skills in:• Intel 64 and IA-32 architecture• C and Assembly language• hot-spot regions in the application that have impact on performance• optimization capabilities of the compiler• techniques used to evaluate application performanceThe Intel ® VTune Performance Analyzer can help you analyze and locate hot-spotregions in your applications. On the Intel ® Core2 Duo, Intel Core Duo, Intel CoreSolo, Pentium 4, Intel ® Xeon ® and Pentium M processors, this tool can monitor anapplication through a selection of performance monitoring events and analyze theperformance event data that is gathered during code execution.This manual also describes information that can be gathered using the performancecounters through Pentium 4 processor’s performance monitoring events.1-1