sysdeps/x86_64/fpu/s_truncl.S

   1 /* Truncate long double value.
   2    Copyright (C) 1997-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <libm-alias-ldouble.h>
  20 #include <machine/asm.h>
  21
  22 ENTRY(__truncl)
  23         fldt    8(%rsp)
  24         fnstenv -28(%rsp)
  25         movl    $0xc00, %edx
  26         orl     -28(%rsp), %edx
  27         movl    %edx, -32(%rsp)
  28         fldcw   -32(%rsp)
  29         frndint
  30         fnstsw
  31         andl    $0x1, %eax
  32         orl     %eax, -24(%rsp)
  33         fldenv  -28(%rsp)
  34         ret
  35 END(__truncl)
  36 libm_alias_ldouble (__trunc, trunc)