From 9823f5f495769aa521e9ad4ccb5e9f4d2008591c Mon Sep 17 00:00:00 2001
From: Martin Diehl <m.diehl@mpie.de>
Date: Sat, 12 Aug 2017 04:51:10 +0200
Subject: [PATCH] one time used variables with name a and x to not help,
 assignement of i and j via loop is safe

---
 src/math.f90 | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/src/math.f90 b/src/math.f90
index 3a0533ddf..699ea063e 100644
--- a/src/math.f90
+++ b/src/math.f90
@@ -305,23 +305,17 @@ integer(pInt) function math_partition(a, istart, iend)
  implicit none
  integer(pInt), dimension(:,:), intent(inout) :: a
  integer(pInt), intent(in) :: istart,iend
- integer(pInt) :: d,i,j,k,x,tmp
+ integer(pInt) :: i,j,k,tmp
 
- d = int(size(a,1_pInt), pInt) ! number of linked data
-! set the starting and ending points, and the pivot point
 
- i = istart
-
- j = iend
- x = a(1,istart)
  do
 ! find the first element on the right side less than or equal to the pivot point
-   do j = j, istart, -1_pInt
-     if (a(1,j) <= x) exit
+   do j = iend, istart, -1_pInt
+     if (a(1,j) <= a(1,istart)) exit
    enddo
 ! find the first element on the left side greater than the pivot point
-   do i = i, iend
-     if (a(1,i) > x) exit
+   do i = istart, iend
+     if (a(1,i) > a(1,istart)) exit
    enddo
    if (i < j) then ! if the indexes do not cross, exchange values
      do k = 1_pInt,d
@@ -330,7 +324,7 @@ integer(pInt) function math_partition(a, istart, iend)
       a(k,j) = tmp
      enddo
    else           ! if they do cross, exchange left value with pivot and return with the partition index
-     do k = 1_pInt,d
+     do k = 1_pInt, int(size(a,1_pInt), pInt) ! number of linked data
       tmp = a(k,istart)
       a(k,istart) = a(k,j)
       a(k,j) = tmp