man3/__setfpucw.3

   1 .\" Written Sat Mar  8 10:35:08 MEZ 1997 by J. "MUFTI" Scheurich (mufti@csv.ica.uni-stuttgart.de)
   2 .\" This page is licensed under the GNU General Public License
   3 .\"
   4 .TH __SETFPUCW 3 1997-03-08 "i386 Linux Man Page" "Linux Programmer's Manual"
   5 .SH NAME
   6 __setfpucw \- set fpu control word on i386 architecture (obsolete)
   7 .SH SYNOPSIS
   8 .B #include <i386/fpu_control.h>
   9 .sp
  10 .BI "void __setfpucw((unsigned short) " control_word );
  11 .br
  12 .SH DESCRIPTION
  13 .BR __setfpucw ()
  14 transfers
  15 .I control_word
  16 to the registers of the fpu (floating point unit) on i386 architecture. This
  17 was used to control floating point precision, rounding and floating point
  18 exceptions.
  19 .SH EXAMPLE
  20
  21 .BR __setfpucw(0x1372)
  22
  23 Set fpu control word on i386 architecture to
  24 .br
  25      \- extended precision
  26 .br
  27      \- rounding to nearest
  28 .br
  29      \- exceptions on overflow, zero divide and NaN
  30 .br
  31 .SH AVAILABILITY
  32 As of glibc 2.1 this function does not exist anymore.
  33 There are new functions from C99, with prototypes in
  34 .IR /usr/include/fenv.h ,
  35 to control fpu rounding modes, like
  36 .IR fegetround ,
  37 .IR fesetround ,
  38 and the floating point environment, like
  39 .IR fegetenv ,
  40 .IR feholdexcept ,
  41 .IR fesetenv ,
  42 .IR feupdateenv
  43 and fpu exception handling, like
  44 .IR feclearexcept ,
  45 .IR fegetexceptflag ,
  46 .IR feraiseexcept ,
  47 .IR fesetexceptflag ,
  48 .IR fetestexcept .
  49 .PP
  50 If direct access to the FPU control word is still needed, the _FPU_GETCW
  51 and _FPU_SETCW macros from
  52 .I /usr/include/fpu_control.h
  53 can be used.
  54 .SH "SEE ALSO"
  55 .BR feclearexcept (3)
  56 .br
  57 .IR /usr/include/i386/fpu_control.h