__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 round-
ing modes, like fegetround, fesetround, and the floating-point environment, like fegetenv, feholdexcept, fesetenv, feupdateenv and FPU
exception handling, like feclearexcept, fegetexceptflag, feraiseexcept, fesetexceptflag, fetestexcept.
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 3.25 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/.
Linux 1997-03-08 __SETFPUCW(3)