+#define SMALL 8
+#define SWAP(a,b) { itmp=(a); (a)=(b); (b)=itmp; }
+
+void
+mdb_midl_sort( IDL ids )
+{
+ /* Max possible depth of int-indexed tree * 2 items/level */
+ int istack[sizeof(int)*CHAR_BIT * 2];
+ int i,j,k,l,ir,jstack;
+ ID a, itmp;
+
+ ir = ids[0];
+ l = 1;
+ jstack = 0;
+ for(;;) {
+ if (ir - l < SMALL) { /* Insertion sort */
+ for (j=l+1;j<=ir;j++) {
+ a = ids[j];
+ for (i=j-1;i>=1;i--) {
+ if (ids[i] >= a) break;
+ ids[i+1] = ids[i];
+ }
+ ids[i+1] = a;
+ }
+ if (jstack == 0) break;
+ ir = istack[jstack--];
+ l = istack[jstack--];
+ } else {
+ k = (l + ir) >> 1; /* Choose median of left, center, right */
+ SWAP(ids[k], ids[l+1]);
+ if (ids[l] < ids[ir]) {
+ SWAP(ids[l], ids[ir]);
+ }
+ if (ids[l+1] < ids[ir]) {
+ SWAP(ids[l+1], ids[ir]);
+ }
+ if (ids[l] < ids[l+1]) {
+ SWAP(ids[l], ids[l+1]);
+ }
+ i = l+1;
+ j = ir;
+ a = ids[l+1];
+ for(;;) {
+ do i++; while(ids[i] > a);
+ do j--; while(ids[j] < a);
+ if (j < i) break;
+ SWAP(ids[i],ids[j]);
+ }
+ ids[l+1] = ids[j];
+ ids[j] = a;
+ jstack += 2;
+ if (ir-i+1 >= j-1) {
+ istack[jstack] = ir;
+ istack[jstack-1] = i;
+ ir = j-1;
+ } else {
+ istack[jstack] = j-1;
+ istack[jstack-1] = l;
+ l = i;
+ }
+ }
+ }
+}
+
+unsigned mdb_mid2l_search( ID2L ids, ID id )