sysdeps/sparc/sparc32/sparcv9/fpu/s_truncf.S

   1 /* Truncate argument to nearest integral value not larger than
   2    the argument, sparc32 v9 version.
   3
   4    Copyright (C) 2013 Free Software Foundation, Inc.
   5    This file is part of the GNU C Library.
   6    Contributed by David S. Miller <davem@davemloft.net>, 2013.
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 2.1 of the License, or (at your option) any later version.
  12
  13    The GNU C Library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Lesser General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public
  19    License along with the GNU C Library; if not, see
  20    <http://www.gnu.org/licenses/>.  */
  21
  22 #include <sysdep.h>
  23
  24         /* We pop constants into the FPU registers using the incoming
  25            argument stack slots, since this avoid having to use any PIC
  26            references.  We also thus avoid having to allocate a register
  27            window.
  28
  29            VIS instructions are used to facilitate the formation of
  30            easier constants, and the propagation of the sign bit.  */
  31
  32 #define TWO_TWENTYTHREE 0x4b000000              /* 2**23 */
  33
  34 #define ZERO            %f10                    /* 0.0 */
  35 #define SIGN_BIT        %f12                    /* -0.0 */
  36
  37 ENTRY (__truncf)
  38         st      %o0, [%sp + 68]
  39         sethi   %hi(TWO_TWENTYTHREE), %o2
  40         fzeros  ZERO
  41         ld      [%sp + 68], %f1
  42         fnegs   ZERO, SIGN_BIT
  43         st      %o2, [%sp + 68]
  44         fabss   %f1, %f14
  45         ld      [%sp + 68], %f16
  46         fcmps   %fcc3, %f14, %f16
  47         fmovsuge %fcc3, ZERO, %f14
  48         fands   %f1, SIGN_BIT, SIGN_BIT
  49         fstoi   %f14, %f14
  50         fitos   %f14, %f14
  51         fadds   %f1, ZERO, %f18
  52         fmovsuge %fcc3, %f18, %f14
  53         retl
  54          fors   %f14, SIGN_BIT, %f0
  55 END (__truncf)
  56 weak_alias (__truncf, truncf)