generic swap(): lib/sort.c: rename swap to swap_func
This is to avoid name clashes for the introduction of a global swap() macro. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1 changed files with 16 additions and 14 deletions
30
lib/sort.c
30
lib/sort.c
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@ -32,11 +32,11 @@ static void generic_swap(void *a, void *b, int size)
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* @base: pointer to data to sort
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* @num: number of elements
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* @size: size of each element
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* @cmp: pointer to comparison function
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* @swap: pointer to swap function or NULL
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* @cmp_func: pointer to comparison function
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* @swap_func: pointer to swap function or NULL
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*
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* This function does a heapsort on the given array. You may provide a
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* swap function optimized to your element type.
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* swap_func function optimized to your element type.
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*
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* Sorting time is O(n log n) both on average and worst-case. While
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* qsort is about 20% faster on average, it suffers from exploitable
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@ -45,37 +45,39 @@ static void generic_swap(void *a, void *b, int size)
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*/
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void sort(void *base, size_t num, size_t size,
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int (*cmp)(const void *, const void *),
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void (*swap)(void *, void *, int size))
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int (*cmp_func)(const void *, const void *),
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void (*swap_func)(void *, void *, int size))
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{
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/* pre-scale counters for performance */
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int i = (num/2 - 1) * size, n = num * size, c, r;
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if (!swap)
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swap = (size == 4 ? u32_swap : generic_swap);
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if (!swap_func)
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swap_func = (size == 4 ? u32_swap : generic_swap);
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/* heapify */
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for ( ; i >= 0; i -= size) {
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for (r = i; r * 2 + size < n; r = c) {
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c = r * 2 + size;
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if (c < n - size && cmp(base + c, base + c + size) < 0)
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if (c < n - size &&
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cmp_func(base + c, base + c + size) < 0)
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c += size;
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if (cmp(base + r, base + c) >= 0)
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if (cmp_func(base + r, base + c) >= 0)
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break;
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swap(base + r, base + c, size);
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swap_func(base + r, base + c, size);
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}
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}
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/* sort */
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for (i = n - size; i > 0; i -= size) {
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swap(base, base + i, size);
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swap_func(base, base + i, size);
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for (r = 0; r * 2 + size < i; r = c) {
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c = r * 2 + size;
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if (c < i - size && cmp(base + c, base + c + size) < 0)
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if (c < i - size &&
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cmp_func(base + c, base + c + size) < 0)
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c += size;
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if (cmp(base + r, base + c) >= 0)
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if (cmp_func(base + r, base + c) >= 0)
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break;
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swap(base + r, base + c, size);
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swap_func(base + r, base + c, size);
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}
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}
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}
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