__setfpucw - set FPU control word on i386 architecture (obsolete)
Contents
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.
Examples
__setfpucw(0x1372)
Set FPU control word on the i386 architecture to
• extended precision
• rounding to nearest
• exceptions on overflow, zero divide and NaN
History
Removed in glibc 2.1.
Library
Standard C library (libc, -lc)
Name
__setfpucw - set FPU control word on i386 architecture (obsolete)
Notes
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.
See Also
feclearexcept(3) <fpu_control.h> Linux man-pages 6.9.1 2024-05-02 __setfpucw(3)
Standards
GNU.
Synopsis
#include<i386/fpu_control.h>[[deprecated]]void__setfpucw(unsignedshortcontrol_word);
