Avoid creating shift-by-zero SDNodes in the common case of
i8* getelementptr. DAGCombine eliminates these, but this is
a fairly common case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55214 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index e13cfc0..147f45c 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2814,16 +2814,17 @@
// If this is a multiply by a power of two, turn it into a shl
// immediately. This is a very common case.
- if (isPowerOf2_64(ElementSize)) {
- unsigned Amt = Log2_64(ElementSize);
- IdxN = DAG.getNode(ISD::SHL, N.getValueType(), IdxN,
- DAG.getConstant(Amt, TLI.getShiftAmountTy()));
- N = DAG.getNode(ISD::ADD, N.getValueType(), N, IdxN);
- continue;
+ if (ElementSize != 1) {
+ if (isPowerOf2_64(ElementSize)) {
+ unsigned Amt = Log2_64(ElementSize);
+ IdxN = DAG.getNode(ISD::SHL, N.getValueType(), IdxN,
+ DAG.getConstant(Amt, TLI.getShiftAmountTy()));
+ } else {
+ SDValue Scale = DAG.getIntPtrConstant(ElementSize);
+ IdxN = DAG.getNode(ISD::MUL, N.getValueType(), IdxN, Scale);
+ }
}
-
- SDValue Scale = DAG.getIntPtrConstant(ElementSize);
- IdxN = DAG.getNode(ISD::MUL, N.getValueType(), IdxN, Scale);
+
N = DAG.getNode(ISD::ADD, N.getValueType(), N, IdxN);
}
}