reactos/lib/ntdll/rtl/i386/ftol.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:         See COPYING in the top level directory
   4  * PROJECT:           ReactOS kernel
   5  * PURPOSE:           Security manager
   6  * FILE:              lib/ntdll/rtl/i386/ftol.c
   7  * PROGRAMER:         Ge van Geldorp (ge@gse.nl)
   8  * REVISION HISTORY:  2003/04/24 Created
   9  */
  10
  11 /*
  12  * This routine is called by MSVC-generated code to convert from floating point
  13  * to integer representation. The floating point number to be converted is
  14  * on the top of the floating point stack.
  15  */
  16 long long __cdecl _ftol(void)
  17 {
  18   unsigned short cw_orig;
  19   unsigned short cw_round_chop;
  20   long long ll;
  21
  22   /* Set "round towards zero" mode */
  23   __asm__("fstcw %0\n\t" : "=m" (cw_orig));
  24   __asm__("fwait\n\t");
  25   cw_round_chop = cw_orig | 0x0c00;
  26   __asm__("fldcw %0\n\t" : : "m" (cw_round_chop));
  27
  28   /* Do the actual conversion */
  29   __asm__("fistpq %0\n\t" : "=m" (ll) );
  30
  31   /* And restore the rounding mode */
  32   __asm__("fldcw %0\n\t" : : "m" (cw_orig));
  33
  34   return ll;
  35 }