mirror of
https://github.com/openvswitch/ovs
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db5a101931
This commit fixes the warning issued by 'clang' when pointer is casted to one with greater alignment. Signed-off-by: Alex Wang <alexw@nicira.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
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* Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <config.h>
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#include "hash.h"
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#include <string.h>
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#include "unaligned.h"
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/* Returns the hash of 'a', 'b', and 'c'. */
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uint32_t
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hash_3words(uint32_t a, uint32_t b, uint32_t c)
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{
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return mhash_finish(mhash_add(mhash_add(mhash_add(a, 0), b), c), 12);
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}
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/* Returns the hash of the 'n' bytes at 'p', starting from 'basis'. */
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uint32_t
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hash_bytes(const void *p_, size_t n, uint32_t basis)
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{
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const uint32_t *p = p_;
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size_t orig_n = n;
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uint32_t hash;
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hash = basis;
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while (n >= 4) {
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hash = mhash_add(hash, get_unaligned_u32(p));
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n -= 4;
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p += 1;
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}
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if (n) {
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uint32_t tmp = 0;
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memcpy(&tmp, p, n);
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hash = mhash_add__(hash, tmp);
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}
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return mhash_finish(hash, orig_n);
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}
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/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
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* 'p' must be properly aligned. */
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uint32_t
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hash_words(const uint32_t p[], size_t n_words, uint32_t basis)
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{
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uint32_t hash;
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size_t i;
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hash = basis;
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for (i = 0; i < n_words; i++) {
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hash = mhash_add(hash, p[i]);
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}
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return mhash_finish(hash, n_words * 4);
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}
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uint32_t
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hash_double(double x, uint32_t basis)
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{
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uint32_t value[2];
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BUILD_ASSERT_DECL(sizeof x == sizeof value);
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memcpy(value, &x, sizeof value);
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return hash_3words(value[0], value[1], basis);
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}
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