6.58.30. x86 Built-in Functions

6.58.30 x86 Built-in Functions

These built-in functions are available for the x86-32 and x86-64 family of computers, depending on the command-line switches used.

If you specify command-line switches such as -msse, the compiler could use the extended instruction sets even if the built-ins are not used explicitly in the program. For this reason, applications that perform run-time CPU detection must compile separate files for each supported architecture, using the appropriate flags. In particular, the file containing the CPU detection code should be compiled without these options.

The following machine modes are available for use with MMX built-in functions (see Vector Extensions): V2SI for a vector of two 32-bit integers, V4HI for a vector of four 16-bit integers, and V8QI for a vector of ei