Fold C ? 0 : 1 to ~C or zext(~C) or trunc(~C) depending the types.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41163 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index b38b479..d9c09e1 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2249,6 +2249,7 @@
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2);
MVT::ValueType VT = N->getValueType(0);
+ MVT::ValueType VT0 = N0.getValueType();
// fold select C, X, X -> X
if (N1 == N2)
@@ -2262,15 +2263,25 @@
// fold select C, 1, X -> C | X
if (MVT::i1 == VT && N1C && N1C->getValue() == 1)
return DAG.getNode(ISD::OR, VT, N0, N2);
+ // fold select C, 0, 1 -> ~C
+ if (MVT::isInteger(VT) && MVT::isInteger(VT0) &&
+ N1C && N2C && N1C->isNullValue() && N2C->getValue() == 1) {
+ SDOperand XORNode = DAG.getNode(ISD::XOR, VT0, N0, DAG.getConstant(1, VT0));
+ if (VT == VT0)
+ return XORNode;
+ AddToWorkList(XORNode.Val);
+ if (MVT::getSizeInBits(VT) > MVT::getSizeInBits(VT0))
+ return DAG.getNode(ISD::ZERO_EXTEND, VT, XORNode);
+ return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
+ }
// fold select C, 0, X -> ~C & X
- // FIXME: this should check for C type == X type, not i1?
- if (MVT::i1 == VT && N1C && N1C->isNullValue()) {
+ if (VT == VT0 && N1C && N1C->isNullValue()) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::AND, VT, XORNode, N2);
}
// fold select C, X, 1 -> ~C | X
- if (MVT::i1 == VT && N2C && N2C->getValue() == 1) {
+ if (VT == VT0 && N2C && N2C->getValue() == 1) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::OR, VT, XORNode, N1);