libgfortran/intrinsics/mvbits.c

   1 /* Implementation of the MVBITS intrinsic
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3    Contributed by Tobias Schlüter
   4
   5 This file is part of the GNU Fortran 95 runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU General Public
   9 License as published by the Free Software Foundation; either
  10 version 2 of the License, or (at your option) any later version.
  11
  12 In addition to the permissions in the GNU General Public License, the
  13 Free Software Foundation gives you unlimited permission to link the
  14 compiled version of this file into combinations with other programs,
  15 and to distribute those combinations without any restriction coming
  16 from the use of this file.  (The General Public License restrictions
  17 do apply in other respects; for example, they cover modification of
  18 the file, and distribution when not linked into a combine
  19 executable.)
  20
  21 Libgfortran is distributed in the hope that it will be useful,
  22 but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 GNU General Public License for more details.
  25
  26 You should have received a copy of the GNU General Public
  27 License along with libgfortran; see the file COPYING.  If not,
  28 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  29 Boston, MA 02111-1307, USA.  */
  30
  31 /* TODO: This should be replaced by a compiler builtin.  */
  32
  33 #ifndef SUB_NAME
  34 #include <libgfortran.h>
  35 #endif
  36
  37 #ifdef SUB_NAME
  38 /* MVBITS copies LEN bits starting at bit position FROMPOS from FROM
  39    into TO, starting at bit position TOPOS.  */
  40
  41 extern void SUB_NAME (const TYPE *, const GFC_INTEGER_4 *,
  42                       const GFC_INTEGER_4 *, TYPE *, const GFC_INTEGER_4 *);
  43 export_proto(SUB_NAME);
  44
  45 void
  46 SUB_NAME (const TYPE *from, const GFC_INTEGER_4 *frompos,
  47           const GFC_INTEGER_4 *len, TYPE *to, const GFC_INTEGER_4 *topos)
  48 {
  49   TYPE oldbits, newbits, lenmask;
  50
  51   lenmask = (*len == sizeof (TYPE)*8) ? ~(TYPE)0 : (1 << *len) - 1;
  52   newbits = (((UTYPE)(*from) >> *frompos) & lenmask) << *topos;
  53   oldbits = *to & (~(lenmask << *topos));
  54
  55   *to = newbits | oldbits;
  56 }
  57 #endif
  58
  59 #ifndef SUB_NAME
  60 #  define TYPE GFC_INTEGER_1
  61 #  define UTYPE GFC_UINTEGER_1
  62 #  define SUB_NAME mvbits_i1
  63 #  include "mvbits.c"
  64 #  undef SUB_NAME
  65 #  undef TYPE
  66 #  undef UTYPE
  67
  68 #  define TYPE GFC_INTEGER_2
  69 #  define UTYPE GFC_UINTEGER_2
  70 #  define SUB_NAME mvbits_i2
  71 #  include "mvbits.c"
  72 #  undef SUB_NAME
  73 #  undef TYPE
  74 #  undef UTYPE
  75
  76 #  define TYPE GFC_INTEGER_4
  77 #  define UTYPE GFC_UINTEGER_4
  78 #  define SUB_NAME mvbits_i4
  79 #  include "mvbits.c"
  80 #  undef SUB_NAME
  81 #  undef TYPE
  82 #  undef UTYPE
  83
  84 #  define TYPE GFC_INTEGER_8
  85 #  define UTYPE GFC_UINTEGER_8
  86 #  define SUB_NAME mvbits_i8
  87 #  include "mvbits.c"
  88 #  undef SUB_NAME
  89 #  undef TYPE
  90 #  undef UTYPE
  91 #endif