__SETFPUCW - reference manual online

__SETFPUCW(3)                       Linux Programmer's Manual                       __SETFPUCW(3)

NAME
       __setfpucw - set FPU control word on i386 architecture (obsolete)

SYNOPSIS
       #include <i386/fpu_control.h>

       void __setfpucw(unsigned short control_word);

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 TO
       This function was a nonstandard GNU extension.

NOTES
       As 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), fes‐
       etround(3), and the floating-point environment, like fegetenv(3), feholdexcept(3), fes‐
       etenv(3), feupdateenv(3), and FPU exception handling, like feclearexcept(3), fegetexcept‐
       flag(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.

EXAMPLE
       __setfpucw(0x1372)

       Set FPU control word on the i386 architecture to
            - extended precision
            - rounding to nearest
            - exceptions on overflow, zero divide and NaN

SEE ALSO
       feclearexcept(3)
       <fpu_control.h>

COLOPHON
       This page is part of release 4.04 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.

Linux                                       2012-12-31                              __SETFPUCW(3)