#include #include void *memset(void *dest, int c, size_t n) { unsigned char *s = dest; size_t k; /* Fill head and tail with minimal branching. Each * conditional ensures that all the subsequently used * offsets are well-defined and in the dest region. */ if (!n) return dest; s[0] = c; s[n-1] = c; if (n <= 2) return dest; s[1] = c; s[2] = c; s[n-2] = c; s[n-3] = c; if (n <= 6) return dest; s[3] = c; s[n-4] = c; if (n <= 8) return dest; /* Advance pointer to align it at a 4-byte boundary, * and truncate n to a multiple of 4. The previous code * already took care of any head/tail that get cut off * by the alignment. */ k = -(uintptr_t)s & 3; s += k; n -= k; n &= -4; /* Pure C fallback with no aliasing violations. */ for (; n; n--, s++) *s = c; return dest; }