[llvm-commits] [llvm] r85394 - /llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Dan Gohman]

Author: djg
Date: Wed Oct 28 10:28:02 2009
New Revision: 85394

URL: http://llvm.org/viewvc/llvm-project?rev=85394&view=rev
Log:
Don't call SDNode::isPredecessorOf when it isn't necessary. If the load's
chains have no users, they can't be predecessors of the condition.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=85394&r1=85393&r2=85394&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Wed Oct 28 10:28:02 2009
@@ -5737,8 +5737,10 @@
         if (TheSelect->getOpcode() == ISD::SELECT) {
           // Check that the condition doesn't reach either load.  If so, folding
           // this will induce a cycle into the DAG.
-          if (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
-              !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode())) {
+          if ((!LLD->hasAnyUseOfValue(1) ||
+               !LLD->isPredecessorOf(TheSelect->getOperand(0).getNode())) &&
+              (!RLD->hasAnyUseOfValue(1) ||
+               !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()))) {
             Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(),
                                LLD->getBasePtr().getValueType(),
                                TheSelect->getOperand(0), LLD->getBasePtr(),
@@ -5747,10 +5749,12 @@
         } else {
           // Check that the condition doesn't reach either load.  If so, folding
           // this will induce a cycle into the DAG.
-          if (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
-              !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
-              !LLD->isPredecessorOf(TheSelect->getOperand(1).getNode()) &&
-              !RLD->isPredecessorOf(TheSelect->getOperand(1).getNode())) {
+          if ((!LLD->hasAnyUseOfValue(1) ||
+               (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
+                !LLD->isPredecessorOf(TheSelect->getOperand(1).getNode()))) &&
+              (!RLD->hasAnyUseOfValue(1) ||
+               (!RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) &&
+                !RLD->isPredecessorOf(TheSelect->getOperand(1).getNode())))) {
             Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(),
                                LLD->getBasePtr().getValueType(),
                                TheSelect->getOperand(0),