The -fp-model (Linux*) or /fp (Windows*) option allows you to control the optimizations on floating-point data. You can use this option to tune the performance, level of accuracy, or result consistency for floating-point applications across platforms and optimization levels.
You can use keywords to specify the semantics to be used. The keywords specified for this option may influence the choice of math routines that are invoked. Many routines in the libirc, libm, and libsvml libraries are more highly optimized for Intel microprocessors than for non-Intel microprocessors. Possible values of the keywords are as follows:
Keyword |
Description |
|---|---|
precise |
Enables value-safe optimizations on floating-point data. |
fast |
Enables more aggressive optimizations on floating-point data. |
double |
Rounds intermediate results to 53-bit (double) precision and enables value-safe optimizations. |
Using the default option keyword -fp-model fast or /fp:fast, you may get significant differences in your result depending on whether the compiler uses x87 or SSE/AVX instructions to implement floating-point operations. Results are more consistent when the other option keywords are used.