Optimize Exclusively for Specific Processors

Using these options, you can produce optimized code that only runs on a target processor or later processors. The resulting code may use extensions for the target processor, while not providing any conditional code to support processors earlier than the target processor.

Option

Description

Notes

Windows*

Linux*

-Qxi

-xi

Pentium® Pro processor and Pentium II processor with CMOV and FCMOV and FCOMI instructions

 

-QxM

-xM

Pentium processor with MMX™ instructions

 

-QxK

-xK

Pentium III processor with Streaming SIMD Extensions

implies i and M above

-QxW

-xW

Pentium 4 processor with Streaming SIMD Extensions 2

implies i, M and K above

If a program compiled with any of these options is executed on a processor that lacks the specified extensions, it can fail with an illegal instruction exception or display other unexpected behavior.

For the target processor, the compiler uses:

  • processor-specific opcodes
  • prefetch operations (Pentium III processor only)
  • vectorization