Sort the pivot, lo and hi value immediately in-place

tekverkp · Sep 17, 2018 · 93091e7 · 93091e7
1 parent 88f74b7
commit 93091e7
Showing 1 changed file with 9 additions and 13 deletions.
diff --git a/base/sort.jl b/base/sort.jl
@@ -477,26 +477,22 @@ end
  @inbounds begin
  mi = (lo+hi)>>>1
 
- # sort the values in v[lo], v[mi], v[hi]
-
- if lt(o, v[mi], v[lo])
+ # sort v[mi] <= v[lo] <= v[hi] such that the pivot is immediately in place
+ if lt(o, v[lo], v[mi])
  v[mi], v[lo] = v[lo], v[mi]
  end
- if lt(o, v[hi], v[mi])
- if lt(o, v[hi], v[lo])
- v[lo], v[mi], v[hi] = v[hi], v[lo], v[mi]
+
+ if lt(o, v[hi], v[lo])
+ if lt(o, v[hi], v[mi])
+ v[hi], v[lo], v[mi] = v[lo], v[mi], v[hi]
  else
- v[hi], v[mi] = v[mi], v[hi]
+ v[hi], v[lo] = v[lo], v[hi]
  end
  end
 
- # move v[mi] to v[lo] and use it as the pivot
- v[lo], v[mi] = v[mi], v[lo]
- pivot = v[lo]
+ # return the pivot
+ return v[lo]
  end
-
- # return the pivot
- return pivot
 end
 
 # partition!