diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index b4a7f04272d9a..04dab3e993420 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -386,28 +386,26 @@ final class WindowState implements WindowManagerPolicy.WindowState {
             mAttachedWindow = attachedWindow;
             if (WindowManagerService.DEBUG_ADD_REMOVE) Slog.v(TAG, "Adding " + this + " to " + mAttachedWindow);
 
-            int children_size = mAttachedWindow.mChildWindows.size();
-            if (children_size == 0) {
-                mAttachedWindow.mChildWindows.add(this);
+            final WindowList childWindows = mAttachedWindow.mChildWindows;
+            final int numChildWindows = childWindows.size();
+            if (numChildWindows == 0) {
+                childWindows.add(this);
             } else {
-                for (int i = 0; i < children_size; i++) {
-                    WindowState child = (WindowState)mAttachedWindow.mChildWindows.get(i);
-                    if (this.mSubLayer < child.mSubLayer) {
-                        mAttachedWindow.mChildWindows.add(i, this);
+                boolean added = false;
+                for (int i = 0; i < numChildWindows; i++) {
+                    final int childSubLayer = childWindows.get(i).mSubLayer;
+                    if (mSubLayer < childSubLayer
+                            || (mSubLayer == childSubLayer && childSubLayer < 0)) {
+                        // We insert the child window into the list ordered by the sub-layer. For
+                        // same sub-layers, the negative one should go below others; the positive
+                        // one should go above others.
+                        childWindows.add(i, this);
+                        added = true;
                         break;
-                    } else if (this.mSubLayer > child.mSubLayer) {
-                        continue;
-                    }
-
-                    if (this.mBaseLayer <= child.mBaseLayer) {
-                        mAttachedWindow.mChildWindows.add(i, this);
-                        break;
-                    } else {
-                        continue;
                     }
                 }
-                if (children_size == mAttachedWindow.mChildWindows.size()) {
-                    mAttachedWindow.mChildWindows.add(this);
+                if (!added) {
+                    childWindows.add(this);
                 }
             }