__setfpucw(3) | Library Functions Manual | __setfpucw(3) |
NAME¶
__setfpucw - set FPU control word on i386 architecture (obsolete)
LIBRARY¶
Standard C library (libc, -lc)
SYNOPSIS¶
#include <i386/fpu_control.h>
[[deprecated]] 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.
STANDARDS¶
GNU.
HISTORY¶
Removed in glibc 2.1.
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.
EXAMPLES¶
__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¶
<fpu_control.h>
2024-05-02 | Linux man-pages 6.9.1 |