[llvm-commits] [llvm] r97211 - /llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp

[Sanjiv Gupta]

Author: sgupta
Date: Fri Feb 26 01:27:35 2010
New Revision: 97211

URL: http://llvm.org/viewvc/llvm-project?rev=97211&view=rev
Log:
Before converting an operand to mem, check if it is legal to do so.

Modified:
    llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp

Modified: llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp?rev=97211&r1=97210&r2=97211&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/PIC16/PIC16ISelLowering.cpp Fri Feb 26 01:27:35 2010
@@ -1527,10 +1527,24 @@
     return true;
 
   if (isDirectLoad(Op.getOperand(1))) {
-    if (Op.getOperand(1).hasOneUse())
-      return false;
-    else 
-      MemOp = 1; 
+    if (Op.getOperand(1).hasOneUse()) {
+      // Legal and profitable folding check uses the NodeId of DAG nodes.
+      // This NodeId is assigned by topological order. Therefore first 
+      // assign topological order then perform legal and profitable check.
+      // Note:- Though this ordering is done before begining with legalization,
+      // newly added node during legalization process have NodeId=-1 (NewNode)
+      // therefore before performing any check proper ordering of the node is
+      // required.
+      DAG.AssignTopologicalOrder();
+
+      // Direct load operands are folded in binary operations. But before folding
+      // verify if this folding is legal. Fold only if it is legal otherwise
+      // convert this direct load to a separate memory operation.
+      if(ISel->IsLegalToFold(Op.getOperand(1), Op.getNode(), Op.getNode()))
+         return false;
+      else 
+         MemOp = 1; 
+    }
   }
   return true;
 }