Intel ARCHITECTURE IA-32 User Manual

IA-32 Intel® Architecture Optimization
3-2
Checking for Processor Support of SIMD
Technologies
This section shows how to check whether a processor supports MMX
technology, SSE, SSE2, or SSE3.
SIMD technology can be included in your application in three ways:
1. Check for the SIMD technology during installation. If the desired
SIMD technology is available, the appropriate DLLs can be
installed.
2. Check for the SIMD technology during program execution and
install the proper DLLs at runtime. This is effective for programs
that may be executed on different machines.
3. Create a “fat” binary that includes multiple versions of routines;
versions that use SIMD technology and versions that do not. Check
for SIMD technology during program execution and run the
appropriate versions of the routines. This is especially effective for
programs that may be executed on different machines.
Checking for MMX Technology Support
To check if MMX technology is available on your system, use cpuid to
and check the feature flags in the
edx register. If cpuid returns bit 23
set to 1 in the feature flags, the processor supports MMX technology.
Use the code segment in Example 3-1 to test for the existence of MMX
technology.

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)