__setfpucw3
Set fpu control word on i386 architecture (obsolete)
Usage
#include <i386/fpu_control.h>
[[deprecated]] void __setfpucw(unsigned short control_word);
Library
Standard C library (libc, -lc)
Overview
__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.
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
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extended precision |
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rounding to nearest |
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exceptions on overflow, zero divide and NaN |
Releases
16 releases since Debian 2.0 (Hamm); the text changed 14 times.