From: Ruchira Sasanka <sasanka@students.uiuc.edu>
Date: Tue, 8 Jan 2002 16:29:23 +0000 (+0000)
Subject: Fixed a bug in spill cost estimation
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ce773da22344a3942b41dc2019d839f3e9231c21;p=oota-llvm.git

Fixed a bug in spill cost estimation


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1500 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/RegAlloc/RegClass.cpp b/lib/CodeGen/RegAlloc/RegClass.cpp
index 3ee79e328e8..3918871d69f 100644
--- a/lib/CodeGen/RegAlloc/RegClass.cpp
+++ b/lib/CodeGen/RegAlloc/RegClass.cpp
@@ -150,9 +150,9 @@ IGNode * RegClass::getIGNodeWithMinSpillCost()
 {
 
   unsigned int IGNodeListSize = IG.getIGNodeList().size(); 
-  long MinSpillCost = -1;
+  double MinSpillCost;
   IGNode *MinCostIGNode = NULL;
-
+  bool isFirstNode = true;
 
   // pass over IGNodeList to find the IGNode with minimum spill cost
   // among all IGNodes that are not yet pushed on to the stack
@@ -165,11 +165,13 @@ IGNode * RegClass::getIGNodeWithMinSpillCost()
 
     if( ! IGNode->isOnStack() ) {
 
-      long SpillCost = (long) IGNode->getParentLR()->getSpillCost();
+      double SpillCost = (double) IGNode->getParentLR()->getSpillCost() /
+	(double) (IGNode->getCurDegree() + 1);
     
-      if( MinSpillCost == -1) {         // for the first IG node
+      if( isFirstNode ) {         // for the first IG node
 	MinSpillCost = SpillCost;
 	MinCostIGNode = IGNode;
+	isFirstNode = false;
       }
 
       else if( MinSpillCost > SpillCost) {
diff --git a/lib/Target/SparcV9/RegAlloc/RegClass.cpp b/lib/Target/SparcV9/RegAlloc/RegClass.cpp
index 3ee79e328e8..3918871d69f 100644
--- a/lib/Target/SparcV9/RegAlloc/RegClass.cpp
+++ b/lib/Target/SparcV9/RegAlloc/RegClass.cpp
@@ -150,9 +150,9 @@ IGNode * RegClass::getIGNodeWithMinSpillCost()
 {
 
   unsigned int IGNodeListSize = IG.getIGNodeList().size(); 
-  long MinSpillCost = -1;
+  double MinSpillCost;
   IGNode *MinCostIGNode = NULL;
-
+  bool isFirstNode = true;
 
   // pass over IGNodeList to find the IGNode with minimum spill cost
   // among all IGNodes that are not yet pushed on to the stack
@@ -165,11 +165,13 @@ IGNode * RegClass::getIGNodeWithMinSpillCost()
 
     if( ! IGNode->isOnStack() ) {
 
-      long SpillCost = (long) IGNode->getParentLR()->getSpillCost();
+      double SpillCost = (double) IGNode->getParentLR()->getSpillCost() /
+	(double) (IGNode->getCurDegree() + 1);
     
-      if( MinSpillCost == -1) {         // for the first IG node
+      if( isFirstNode ) {         // for the first IG node
 	MinSpillCost = SpillCost;
 	MinCostIGNode = IGNode;
+	isFirstNode = false;
       }
 
       else if( MinSpillCost > SpillCost) {