__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 (float‐
ing-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(3), fesetround(3), and the floating-point
environment, like fegetenv(3), feholdexcept(3), fesetenv(3), feupda‐
teenv(3), and FPU exception handling, like feclearexcept(3), fegetex‐
ceptflag(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 ALSOfeclearexcept(3)
<fpu_control.h>
COLOPHON
This page is part of release 3.65 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 2012-12-31 __SETFPUCW(3)
