[llvm-commits] CVS: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Chris Lattner]

Changes in directory llvm/lib/CodeGen/SelectionDAG:

DAGCombiner.cpp updated: 1.30 -> 1.31
---
Log message:

Add a canonicalization that got lost, fixing PowerPC/fold-li.ll:SUB


---
Diffs of the changes:  (+5 -3)

 DAGCombiner.cpp |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)


Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.30 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.31
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.30	Mon Oct 10 18:00:08 2005
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp	Tue Oct 11 01:07:15 2005
@@ -517,9 +517,11 @@
   if (N0C && N1C)
     return DAG.getConstant(N0C->getValue() - N1C->getValue(),
                            N->getValueType(0));
-  // fold (sub x, 0) -> x
-  if (N1C && N1C->isNullValue())
-    return N0;
+  // fold (sub x, c) -> (add x, -c)
+  if (N1C)
+    return DAG.getNode(ISD::ADD, N0.getValueType(), N0,
+                       DAG.getConstant(-N1C->getValue(), N0.getValueType()));
+
   // fold (A+B)-A -> B
   if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
     return N0.getOperand(1);