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Commit dbbcc222 authored by Alex A.'s avatar Alex A.

Fix qsort

parent 7be3309d
/*
* algorithm.c
*
* Copyright (C) 2017 Aleksandar Andrejevic <theflash@sdf.lonestar.org>
* Copyright (C) 2019 Aleksandar Andrejevic <theflash@sdf.lonestar.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
......@@ -22,26 +22,25 @@
void __CRT_PUBLIC(qsort)(void *base, size_t nmemb, size_t size, int (*compare)(const void*, const void*))
{
void *pivot = (void*)((uintptr_t)base + (nmemb / 2) * size);
void *temp = __builtin_alloca(size);
if (nmemb <= 1) return;
char *bytes = base, pivot[size], temp[size];
ptrdiff_t low = 0, high = nmemb - 1;
size_t low = 0;
size_t high = nmemb - 1;
if (nmemb <= 1) return;
__builtin_memcpy(pivot, &bytes[(nmemb / 2 - 1) * size], size);
for (;;)
{
while (compare((void*)((uintptr_t)base + low * size), pivot) < 0) low++;
while (compare((void*)((uintptr_t)base + high * size), pivot) > 0) high--;
while (compare(&bytes[low * size], pivot) < 0) low++;
while (compare(&bytes[high * size], pivot) > 0) high--;
if (low >= high) break;
__builtin_memcpy(temp, (void*)((uintptr_t)base + low * size), size);
__builtin_memcpy((void*)((uintptr_t)base + low * size), (void*)((uintptr_t)base + high * size), size);
__builtin_memcpy((void*)((uintptr_t)base + high * size), temp, size);
__builtin_memcpy(temp, &bytes[low * size], size);
__builtin_memcpy(&bytes[low * size], &bytes[high * size], size);
__builtin_memcpy(&bytes[high * size], temp, size);
}
__CRT_PUBLIC(qsort)(base, high, size, compare);
__CRT_PUBLIC(qsort)((void*)((size_t)base + high * size), nmemb - high, size, compare);
__CRT_PUBLIC(qsort)(bytes, high + 1, size, compare);
__CRT_PUBLIC(qsort)(&bytes[(high + 1) * size], nmemb - (high + 1), size, compare);
}
void *__CRT_PUBLIC(bsearch)(const void *key, const void *base, size_t nmemb, size_t size, int (*compare)(const void*, const void*))
......
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