This section describes targeting a processor and processor dispatch options. -tpp{5|6|7} optimizes non-specifically for the IA-32 processor, while -x{i|M|K|W} and -ax{i|M|K|W} provide support to generate processor instruction extensions that are specific to the architecture.
Option | Description |
---|---|
-tpp{5|6|7} | Schedules instructions for optimal performance on the architecture
specified by 5, 6, 7
-tpp5 |
-x{i|M|K|W} | Generates specialized code to run exclusively on the processors supporting the extensions indicated by the i, M, K, W codes. |
-ax{i|M|K|W} | Generates specialized code to run exclusively on the processors supporting the extensions indicated by the i, M, K, W codes while also generating generic IA-32 code in the same executable. |
For example, on a Pentium III processor, if you have mostly integer code and only a small portion of floating-point code, you may want to compile with -axM rather than -axK because MMX(TM) technology extensions perform the best with integer data and the optimized code will run on a larger subset of Intel processors.
The -ax and -x options
are backward compatible with the extensions supported. The Intel