Syntax:
The /tune option specifies the type of processor-specific machine-code instruction tuning for implementations of the processor architecture in use.
Tuning for a specific implementation can improve run-time performance; it is also possible that code tuned for a specific processor may run slower on another processor. Regardless of the /tune:keyword option you use, the generated code runs correctly on all implementations of the processor architecture.
If you omit /tune:keyword, /tune:generic is used. In the visual development environment, specify the Optimize For in the Optimizations Compiler Option Category.
For ia32 (32-bit Intel and AMD) systems, the /tune keywords are:
Generates and schedules code (sometimes called blended code) that will execute well for all ia32 systems. This provides generally efficient code for those applications where all ia32 processor generations are likely to be used. This is the default.
Generates and schedules code optimized for the processor type in use on the processor system being used for compilation.
Generates and schedules code optimized for the Pentium (586) processor systems. The pn1 keyword replaces the p5 keyword (specifying /tune:pn1 and /tune:p5 are equivalent).
Generates and schedules code optimized for Pentium Pro, Pentium II, and AMD K6 processor systems. The pn2 keyword replaces the p6 keyword (specifying /tune:pn2 and /tune:p6 are equivalent).
Generates and schedules code optimized for AMD K6, Pentium Pro, and Pentium II processor systems (/tune:pn2 and /tune:k6 are the same).
Generates and schedules code optimized for Pentium III, AMD K6_2, and AMD K6_III processor systems. The pn3 keyword replaces the p6p keyword (specifying /tune:pn3 and /tune:p6p are equivalent).
Generates and schedules code optimized for AMD K6_2 and AMD K6_III processor systems.
Generates and schedules code optimized for AMD Athlon processor systems.
Generates and schedules code optimized for Pentium IV processor systems.
Specifying /fast sets /tune:host.
For ia64 (64-bit) systems, specify either /tune:generic or /tune:host (this option is not yet fully implemented for ia64 systems).
The architecture selected by /architecture (code generation option) is the basis for the architecture used by the /tune keyword. For example, you cannot specify a /tune keyword for an architecture older than the one selected by /architecture.
For more information about this option, see Requesting Optimized Code for a Specific Processor Generation.
For information about timing program execution, see Analyze Program Performance.
To control the processor-specific type of machine-code instructions being generated, see the /architecture:keyword option.