gcc/data-streamer.c

   1 /* Generic streaming support for basic data types.
   2
   3    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@google.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "alias.h"
  26 #include "backend.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "hard-reg-set.h"
  30 #include "options.h"
  31 #include "fold-const.h"
  32 #include "internal-fn.h"
  33 #include "cgraph.h"
  34 #include "data-streamer.h"
  35
  36 /* Pack WORK into BP in a variant of uleb format.  */
  37
  38 void
  39 bp_pack_var_len_unsigned (struct bitpack_d *bp, unsigned HOST_WIDE_INT work)
  40 {
  41   do
  42     {
  43       unsigned int half_byte = (work & 0x7);
  44       work >>= 3;
  45       if (work != 0)
  46         /* More half_bytes to follow.  */
  47         half_byte |= 0x8;
  48
  49       bp_pack_value (bp, half_byte, 4);
  50     }
  51   while (work != 0);
  52 }
  53
  54
  55 /* Pack WORK into BP in a variant of sleb format.  */
  56
  57 void
  58 bp_pack_var_len_int (struct bitpack_d *bp, HOST_WIDE_INT work)
  59 {
  60   int more, half_byte;
  61
  62   do
  63     {
  64       half_byte = (work & 0x7);
  65       /* arithmetic shift */
  66       work >>= 3;
  67       more = !((work == 0 && (half_byte & 0x4) == 0)
  68                || (work == -1 && (half_byte & 0x4) != 0));
  69       if (more)
  70         half_byte |= 0x8;
  71
  72       bp_pack_value (bp, half_byte, 4);
  73     }
  74   while (more);
  75 }
  76
  77
  78 /* Unpack VAL from BP in a variant of uleb format.  */
  79
  80 unsigned HOST_WIDE_INT
  81 bp_unpack_var_len_unsigned (struct bitpack_d *bp)
  82 {
  83   unsigned HOST_WIDE_INT result = 0;
  84   int shift = 0;
  85   unsigned HOST_WIDE_INT half_byte;
  86
  87   while (true)
  88     {
  89       half_byte = bp_unpack_value (bp, 4);
  90       result |= (half_byte & 0x7) << shift;
  91       shift += 3;
  92       if ((half_byte & 0x8) == 0)
  93         return result;
  94     }
  95 }
  96
  97
  98 /* Unpack VAL from BP in a variant of sleb format.  */
  99
 100 HOST_WIDE_INT
 101 bp_unpack_var_len_int (struct bitpack_d *bp)
 102 {
 103   HOST_WIDE_INT result = 0;
 104   int shift = 0;
 105   unsigned HOST_WIDE_INT half_byte;
 106
 107   while (true)
 108     {
 109       half_byte = bp_unpack_value (bp, 4);
 110       result |= (half_byte & 0x7) << shift;
 111       shift += 3;
 112       if ((half_byte & 0x8) == 0)
 113         {
 114           if ((shift < HOST_BITS_PER_WIDE_INT) && (half_byte & 0x4))
 115             result |= - (HOST_WIDE_INT_1U << shift);
 116
 117           return result;
 118         }
 119     }
 120 }