Intel ARCHITECTURE IA-32 User Manual

Coding for SIMD Architectures 3
3-11
specific optimizations. Where appropriate, the coach displays
pseudo-code to suggest the use of highly optimized intrinsics and
functions in the Intel
®
Performance Library Suite. Because VTune
analyzer is designed specifically for all of the Intel architecture
(IA)-based processors, including the Pentium 4 processor, it can offer
these detailed approaches to working with IA. See “Code Optimization
Options” in Appendix A for more details and example of a code coach
advice.
Determine If Code Benefits by Conversion to SIMD Execution
Identifying code that benefits by using SIMD technologies can be
time-consuming and difficult. Likely candidates for conversion are
applications that are highly computation intensive, such as the
following:
• speech compression algorithms and filters
• speech recognition algorithms
• video display and capture routines
• rendering routines
• 3D graphics (geometry)
• image and video processing algorithms
• spatial (3D) audio
• physical modeling (graphics, CAD)
• workstation applications
• encryption algorithms
• complex arithmetics
Generally, good candidate code is code that contains small-sized
repetitive loops that operate on sequential arrays of integers of 8, 16 or
32 bits, single-precision 32-bit floating-point data, double precision
64-bit floating-point data (integer and floating-point data items should
be sequential in memory). The repetitiveness of these loops incurs

Intel ARCHITECTURE IA-32 Specifications

General

Instruction Set	x86
Instruction Set Type	CISC
Memory Segmentation	Supported
Operating Modes	Real mode, Protected mode, Virtual 8086 mode
Max Physical Address Size	36 bits (with PAE)
Max Virtual Address Size	32 bits
Architecture	IA-32 (Intel Architecture 32-bit)
Addressable Memory	4 GB (with Physical Address Extension up to 64 GB)
Floating Point Registers	8 x 80-bit
MMX Registers	8 x 64-bit
SSE Registers	8 x 128-bit
Registers	General-purpose registers (EAX, EBX, ECX, EDX, ESI, EDI, ESP, EBP), Segment registers (CS, DS, SS, ES, FS, GS), Instruction pointer (EIP), Flags register (EFLAGS)
Floating Point Unit	Yes (x87)