Intel ARCHITECTURE IA-32 User Manual Page 183

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Coding for SIMD Architectures 3
3-3
For more information on cpuid see, Intel
®
Processor Identification with
CPUID Instruction, order number 241618.
Checking for Streaming SIMD Extensions Support
Checking for support of Streaming SIMD Extensions (SSE) on your
processor is like checking for MMX technology. However, you must
also check whether your operating system (OS) supports SSE. This is
because the OS needs to manage saving and restoring the state
introduced by SSE for your application to properly function.
To check whether your system supports SSE, follow these steps:
1. Check that your processor supports the
cpuid instruction.
2. Check the feature bits of
cpuid for SSE existence.
3. Check for OS support for SSE.
Example 3-2 shows how to find the SSE feature bit (bit 25) in the
cpuid
feature flags.
Example 3-1 Identification of MMX Technology with cpuid
…identify existence of cpuid instruction
…;
; identify signature is genuine intel
…;
mov eax, 1 ; request for feature flags
cpuid ; 0Fh, 0A2h cpuid instruction
test edx, 00800000h ; is MMX technology bit (bit
; 23)in feature flags equal to 1
jnz Found
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