sysdeps/alpha/fpu/s_ceilf.c

   1 /* Copyright (C) 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Richard Henderson.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <math.h>
  21
  22 float
  23 __ceilf (float x)
  24 {
  25   if (x != 0 && fabsf (x) < 16777216.0f)  /* 1 << FLT_MANT_DIG */
  26     {
  27       float tmp1, tmp2;
  28       unsigned long fpcr0, fpcr1;
  29       unsigned long pinf = 3UL << 58;
  30
  31       /* Set round to +inf.  */
  32       __asm __volatile("excb; mf_fpcr %0" : "=f"(fpcr0));
  33       __asm __volatile("mt_fpcr %0; excb" : : "f"(fpcr0 | pinf));
  34
  35       /* Calculate!
  36          Note that Alpha S_Floating is stored in registers in a
  37          restricted T_Floating format, so we don't even need to
  38          convert back to S_Floating in the end.  The initial
  39          conversion to T_Floating is needed to handle denormals.  */
  40
  41 #ifdef _IEEE_FP_INEXACT
  42       __asm("cvtst/s %3,%2\n\tcvttq/svid %2,%1\n\tcvtqt/suid %1,%0"
  43             : "=f"(x), "=&f"(tmp1), "=&f"(tmp2)
  44             : "f"(x));
  45 #else
  46       __asm("cvtst/s %3,%2\n\tcvttq/svd %2,%1\n\tcvtqt/d %1,%0"
  47             : "=f"(x), "=&f"(tmp1), "=&f"(tmp2)
  48             : "f"(x));
  49 #endif
  50
  51       /* Reset rounding mode, while retaining new exception bits.  */
  52       __asm __volatile("excb; mf_fpcr %0" : "=f"(fpcr1));
  53       fpcr0 = (fpcr0 & pinf) | (fpcr1 & ~pinf);
  54       __asm __volatile("mt_fpcr %0; excb" : : "f"(fpcr0));
  55     }
  56   return x;
  57 }
  58
  59 weak_alias (__ceilf, ceilf)