NAME | SYNOPSIS | DESCRIPTION | CONFORMING TO | NOTES | EXAMPLE | SEE ALSO | COLOPHON

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

NAME         top

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

SYNOPSIS         top

       #include <i386/fpu_control.h>

       void __setfpucw(unsigned short control_word);

DESCRIPTION         top

       __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         top

       This function was a nonstandard GNU extension.

NOTES         top

       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), 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.

EXAMPLE         top

       __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         top

       feclearexcept(3)
       <fpu_control.h>

COLOPHON         top

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Linux                            2012-12-31                    __SETFPUCW(3)