|__SETFPUCW(3)||Linux Programmer's Manual||__SETFPUCW(3)|
NAME__setfpucw - set FPU control word on i386 architecture (obsolete)
DESCRIPTION__setfpucw() transfers control_word to the registers of the FPU (floating-point unit) on the i386 architecture. This was used to control floating-point precision, rounding and floating-point exceptions.
CONFORMING TOThis function was a nonstandard GNU extension.
NOTESAs of glibc 2.1 this function does not exist anymore. There are new functions from C99, with prototypes in <fenv.h>, to control FPU rounding modes, like fegetround(3), fesetround(3), and the floating-point environment, like fegetenv(3), feholdexcept(3), fesetenv(3), feupdateenv(3), and FPU exception handling, like feclearexcept(3), fegetexceptflag(3), feraiseexcept(3), fesetexceptflag(3), and fetestexcept(3).
If direct access to the FPU control word is still needed, the _FPU_GETCW and _FPU_SETCW macros from <fpu_control.h> can be used.
- extended precision
- rounding to nearest
- exceptions on overflow, zero divide and NaN
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.