1 /* Generic streaming support for basic data types.
2 
3    Copyright (C) 2011-2018 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 "backend.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "cgraph.h"
29 #include "data-streamer.h"
30 
31 /* Pack WORK into BP in a variant of uleb format.  */
32 
33 void
34 bp_pack_var_len_unsigned (struct bitpack_d *bp, unsigned HOST_WIDE_INT work)
35 {
36   do
37     {
38       unsigned int half_byte = (work & 0x7);
39       work >>= 3;
40       if (work != 0)
41 	/* More half_bytes to follow.  */
42 	half_byte |= 0x8;
43 
44       bp_pack_value (bp, half_byte, 4);
45     }
46   while (work != 0);
47 }
48 
49 
50 /* Pack WORK into BP in a variant of sleb format.  */
51 
52 void
53 bp_pack_var_len_int (struct bitpack_d *bp, HOST_WIDE_INT work)
54 {
55   int more, half_byte;
56 
57   do
58     {
59       half_byte = (work & 0x7);
60       /* arithmetic shift */
61       work >>= 3;
62       more = !((work == 0 && (half_byte & 0x4) == 0)
63 	       || (work == -1 && (half_byte & 0x4) != 0));
64       if (more)
65 	half_byte |= 0x8;
66 
67       bp_pack_value (bp, half_byte, 4);
68     }
69   while (more);
70 }
71 
72 
73 /* Unpack VAL from BP in a variant of uleb format.  */
74 
75 unsigned HOST_WIDE_INT
76 bp_unpack_var_len_unsigned (struct bitpack_d *bp)
77 {
78   unsigned HOST_WIDE_INT result = 0;
79   int shift = 0;
80   unsigned HOST_WIDE_INT half_byte;
81 
82   while (true)
83     {
84       half_byte = bp_unpack_value (bp, 4);
85       result |= (half_byte & 0x7) << shift;
86       shift += 3;
87       if ((half_byte & 0x8) == 0)
88 	return result;
89     }
90 }
91 
92 
93 /* Unpack VAL from BP in a variant of sleb format.  */
94 
95 HOST_WIDE_INT
96 bp_unpack_var_len_int (struct bitpack_d *bp)
97 {
98   HOST_WIDE_INT result = 0;
99   int shift = 0;
100   unsigned HOST_WIDE_INT half_byte;
101 
102   while (true)
103     {
104       half_byte = bp_unpack_value (bp, 4);
105       result |= (half_byte & 0x7) << shift;
106       shift += 3;
107       if ((half_byte & 0x8) == 0)
108 	{
109 	  if ((shift < HOST_BITS_PER_WIDE_INT) && (half_byte & 0x4))
110 	    result |= - (HOST_WIDE_INT_1U << shift);
111 
112 	  return result;
113 	}
114     }
115 }
116