| .\" Written Sat Mar 8 10:35:08 MEZ 1997 by J. "MUFTI" Scheurich (mufti@csv.ica.uni-stuttgart.de) |
| .TH __SETFPUCW 3 1997-03-08 "i386 Linux Man Page" "Linux Programmer's Manual" |
| .SH NAME |
| __setfpucw \- set fpu control word on i386 architecture (obsolete) |
| .SH SYNOPSIS |
| .B #include <i386/fpu_control.h> |
| .sp |
| .BI "void __setfpucw((unsigned short) " control_word ); |
| .br |
| .SH DESCRIPTION |
| .BR __setfpucw () |
| transfers |
| .I control_word |
| to the registers of the fpu (floating point unit) on i386 architecture. This |
| was used to control floating point precision, rounding and floating point |
| exceptions. |
| .SH EXAMPLE |
| |
| .BR __setfpucw(0x1372) |
| |
| Set fpu control word on i386 architecture to |
| .br |
| \- extended precision |
| .br |
| \- rounding to nearest |
| .br |
| \- exceptions on overflow, zero divide and NaN |
| .br |
| .SH AVAILABILITY |
| As of glibc 2.1 this function does not exist anymore. |
| There are new functions from ISO C99, with prototypes in |
| .IR /usr/include/fenv.h , |
| to control fpu rounding modes, like |
| .IR fegetround , |
| .IR fesetround , |
| and the floating point environment, like |
| .IR fegetenv , |
| .IR feholdexcept , |
| .IR fesetenv , |
| .IR feupdateenv |
| and fpu exception handling, like |
| .IR feclearexcept , |
| .IR fegetexceptflag , |
| .IR feraiseexcept , |
| .IR fesetexceptflag , |
| .IR fetestexcept . |
| .PP |
| If direct access to the FPU control word is still needed, the _FPU_GETCW |
| and _FPU_SETCW macros from |
| .I /usr/include/fpu_control.h |
| can be used. |
| .SH "SEE ALSO" |
| .BR feclearexcept (3) |
| .br |
| .IR /usr/include/i386/fpu_control.h |