1/* Copyright (C) 1995-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <stdlib.h>
19
20#define TABLE_BASE 0x2e
21#define TABLE_SIZE 0x4d
22
23#define XX ((char)0x40)
24
25
26static const char a64l_table[TABLE_SIZE] =
27{
28 /* 0x2e */ 0, 1,
29 /* 0x30 */ 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, XX, XX, XX, XX, XX, XX,
30 /* 0x40 */ XX, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
31 /* 0x50 */ 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, XX, XX, XX, XX, XX,
32 /* 0x60 */ XX, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
33 /* 0x70 */ 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63
34};
35
36
37long int
38a64l (const char *string)
39{
40 const char *ptr = string;
41 unsigned long int result = 0ul;
42 const char *end = ptr + 6;
43 int shift = 0;
44
45 do
46 {
47 unsigned index;
48 unsigned value;
49
50 index = *ptr - TABLE_BASE;
51 if ((unsigned int) index >= TABLE_SIZE)
52 break;
53 value = (int) a64l_table[index];
54 if (value == (int) XX)
55 break;
56 ++ptr;
57 result |= value << shift;
58 shift += 6;
59 }
60 while (ptr != end);
61
62 return (long int) result;
63}
64

source code of glibc/stdlib/a64l.c