/usr/lib/gcc-cross/powerpc-linux-gnu/6/plugin/include/inchash.h is in gcc-6-plugin-dev-powerpc-linux-gnu 6.4.0-17ubuntu1cross1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 | /* An incremental hash abstract data type.
Copyright (C) 2014-2016 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef INCHASH_H
#define INCHASH_H 1
/* This file implements an incremential hash function ADT, to be used
by code that incrementially hashes a lot of unrelated data
(not in a single memory block) into a single value. The goal
is to make it easy to plug in efficient hash algorithms.
Currently it just implements the plain old jhash based
incremental hash from gcc's tree.c. */
hashval_t iterative_hash_host_wide_int (HOST_WIDE_INT, hashval_t);
hashval_t iterative_hash_hashval_t (hashval_t, hashval_t);
namespace inchash
{
class hash
{
public:
/* Start incremential hashing, optionally with SEED. */
hash (hashval_t seed = 0)
{
val = seed;
bits = 0;
}
/* End incremential hashing and provide the final value. */
hashval_t end ()
{
return val;
}
/* Add unsigned value V. */
void add_int (unsigned v)
{
val = iterative_hash_hashval_t (v, val);
}
/* Add HOST_WIDE_INT value V. */
void add_wide_int (HOST_WIDE_INT v)
{
val = iterative_hash_host_wide_int (v, val);
}
/* Hash in pointer PTR. */
void add_ptr (const void *ptr)
{
add (&ptr, sizeof (ptr));
}
/* Add a memory block DATA with size LEN. */
void add (const void *data, size_t len)
{
val = iterative_hash (data, len, val);
}
/* Merge hash value OTHER. */
void merge_hash (hashval_t other)
{
val = iterative_hash_hashval_t (other, val);
}
/* Hash in state from other inchash OTHER. */
void merge (hash &other)
{
merge_hash (other.val);
}
template<class T> void add_object(T &obj)
{
add (&obj, sizeof(T));
}
/* Support for accumulating boolean flags */
void add_flag (bool flag)
{
bits = (bits << 1) | flag;
}
void commit_flag ()
{
add_int (bits);
bits = 0;
}
/* Support for commutative hashing. Add A and B in a defined order
based on their value. This is useful for hashing commutative
expressions, so that A+B and B+A get the same hash. */
void add_commutative (hash &a, hash &b)
{
if (a.end() > b.end())
{
merge (b);
merge (a);
}
else
{
merge (a);
merge (b);
}
}
private:
hashval_t val;
unsigned bits;
};
}
/* Borrowed from hashtab.c iterative_hash implementation. */
#define mix(a,b,c) \
{ \
a -= b; a -= c; a ^= (c>>13); \
b -= c; b -= a; b ^= (a<< 8); \
c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
}
/* Produce good hash value combining VAL and VAL2. */
inline
hashval_t
iterative_hash_hashval_t (hashval_t val, hashval_t val2)
{
/* the golden ratio; an arbitrary value. */
hashval_t a = 0x9e3779b9;
mix (a, val, val2);
return val2;
}
/* Produce good hash value combining VAL and VAL2. */
inline
hashval_t
iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
{
if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
return iterative_hash_hashval_t (val, val2);
else
{
hashval_t a = (hashval_t) val;
/* Avoid warnings about shifting of more than the width of the type on
hosts that won't execute this path. */
int zero = 0;
hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
mix (a, b, val2);
if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
{
hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
mix (a, b, val2);
}
return val2;
}
}
#endif
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