schwab_sort.h

@@ -158,22 +158,11 @@ static inline int schwab_partition(
 		/* TODO: should be copy of whole element when not just uint32s! */
 		uint32_t curr = arr[b3];
 
-		/* Full branchless - see below for branch alternative */
-		int where = (curr < klo) ? 0 :
-			((curr < kmid) ? 1 : 2);
-		int target = (curr < klo) ? b0 :
-			((curr < kmid) ? b1 : b2);
-
-		arr[b3] = arr[b2];
-		arr[b2] = (where == 2) ? arr[b2] : arr[b1];
-		arr[b1] = (where == 1) ? arr[b1] : arr[b0];
-
-		++b2;
-		b1 += (where < 2);
-		b0 += (where < 1);
-		arr[target] = curr;
-
-		/* Same as this would have been:
+		/* TODO: We can do "ILP-memcpy"s here:
+		 *
+		 * Key from b2->b3, value from b2->b3, key from b1->b2, value from b1... etc
+		 * This is likely faster than calling a memcpy if we code this for not just uint32s!
+		 */
 		if(curr < klo) {
 			arr[b3] = arr[b2];
 			arr[b2] = arr[b1];
@@ -187,13 +176,12 @@ static inline int schwab_partition(
 			arr[b3] = arr[b2];
 			arr[b2] = arr[b1];
 			arr[b1] = curr;
-			++b1;
+			++b1; ++b2;
 		} else {
 			arr[b3] = arr[b2];
 			arr[b2] = curr;
+			++b2;
 		}
-		++b2;
-		*/
 	}
 
 	/* [*] Swap the chosen pivot to begin of last block */