__SETFPUCW - reference manual online

Set FPU control word on i386 architecture (obsolete).

__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
Linux 2012-12-31 __SETFPUCW(3)
This manual Reference Other manuals
__setfpucw(3) referred by
refer to fenv(3)