298 static IdxT partition (lua_State *L, IdxT lo, IdxT up) {  in partition()  argument
299   IdxT i = lo;  /* will be incremented before first use */  in partition()
334 static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) {  in choosePivot()  argument
335   IdxT r4 = (up - lo) / 4;  /* range/4 */  in choosePivot()
336   IdxT p = rnd % (r4 * 2) + (lo + r4);  in choosePivot()
337   lua_assert(lo + r4 <= p && p <= up - r4);  in choosePivot()
345 static void auxsort (lua_State *L, IdxT lo, IdxT up,  in auxsort()  argument
347   while (lo < up) {  /* loop for tail recursion */  in auxsort()
351     lua_geti(L, 1, lo);  in auxsort()
354       set2(L, lo, up);  /* swap a[lo] - a[up] */  in auxsort()
357     if (up - lo == 1)  /* only 2 elements? */  in auxsort()
359     if (up - lo < RANLIMIT || rnd == 0)  /* small interval or no randomize? */  in auxsort()
360       p = (lo + up)/2;  /* middle element is a good pivot */  in auxsort()
362       p = choosePivot(lo, up, rnd);  in auxsort()
364     lua_geti(L, 1, lo);  in auxsort()
366       set2(L, p, lo);  /* swap a[p] - a[lo] */  in auxsort()
375     if (up - lo == 2)  /* only 3 elements? */  in auxsort()
381     p = partition(L, lo, up);  in auxsort()
383     if (p - lo < up - p) {  /* lower interval is smaller? */  in auxsort()
384       auxsort(L, lo, p - 1, rnd);  /* call recursively for lower interval */  in auxsort()
385       n = p - lo;  /* size of smaller interval */  in auxsort()
386       lo = p + 1;  /* tail call for [p + 1 .. up] (upper interval) */  in auxsort()
393     if ((up - lo) / 128 > n) /* partition too imbalanced? */  in auxsort()