From 9d3bbb41dd536a96197280441fe9f8f85a7c3df7 Mon Sep 17 00:00:00 2001
From: Richard Brooksby <rb@ravenbrook.com>
Date: Sat, 22 Feb 2014 19:45:04 +0000
Subject: [PATCH] Moving downward splay updates to after side tree linkage,
 allowing the optimiser to do a better job.  produces about 10% speedup:
 xc/release/djbench -x 1234 --sshift 8 mvff

Copied from Perforce
 Change: 184445
 ServerID: perforce.ravenbrook.com
---
 mps/code/splay.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mps/code/splay.c b/mps/code/splay.c
index 22b0b92e596..ba9d81cdeac 100644
--- a/mps/code/splay.c
+++ b/mps/code/splay.c
@@ -295,8 +295,8 @@ static Compare SplaySplit(Tree *nodeReturn,
           goto assemble;
         }
         TreeRotateRight(&node);
-        tree->updateNode(tree, TreeRight(node));
         SplayLinkRight(&node, &rightFirst);
+        tree->updateNode(tree, TreeRight(rightFirst));
         break;
 
       case CompareGREATER:                 /* zig-zag */
@@ -329,8 +329,8 @@ static Compare SplaySplit(Tree *nodeReturn,
           goto assemble;
         }
         TreeRotateLeft(&node);
-        tree->updateNode(tree, TreeLeft(node));
         SplayLinkLeft(&node, &leftLast);
+        tree->updateNode(tree, TreeLeft(leftLast));
         break;
 
       case CompareLESS:                    /* zag-zig */
@@ -627,7 +627,6 @@ static Tree SplayTreeSuccessor(SplayTree tree) {
  * <design/splay/#impl.neighbours>.
  */
 
-
 Bool SplayTreeNeighbours(Tree *leftReturn, Tree *rightReturn,
                          SplayTree tree, TreeKey key)
 {