[llvm-commits] CVS: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Evan Cheng
evan.cheng at apple.com
Thu Jan 5 17:06:43 PST 2006
Changes in directory llvm/lib/CodeGen/SelectionDAG:
DAGCombiner.cpp updated: 1.77 -> 1.78
---
Log message:
fold (shl x, 1) -> (add x, x)
---
Diffs of the changes: (+3 -0)
DAGCombiner.cpp | 3 +++
1 files changed, 3 insertions(+)
Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.77 llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.78
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:1.77 Wed Jan 4 19:25:28 2006
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Thu Jan 5 19:06:31 2006
@@ -1282,6 +1282,9 @@
// fold (shl x, 0) -> x
if (N1C && N1C->isNullValue())
return N0;
+ // fold (shl x, 1) -> (add x, x)
+ if (N1C && N1C->getValue() == 1)
+ return DAG.getNode(ISD::ADD, VT, N0, N0);
// if (shl x, c) is known to be zero, return 0
if (N1C && MaskedValueIsZero(SDOperand(N, 0), ~0ULL >> (64-OpSizeInBits),TLI))
return DAG.getConstant(0, VT);
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