Merge the duplicated iabs optimization in DAGCombiner and let it detected a few more idioms.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107868 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index a61e9e2..1641f56 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -6892,38 +6892,34 @@
}
}
- // Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
+ // Check to see if this is an integer abs.
+ // select_cc setg[te] X, 0, X, -X ->
+ // select_cc setgt X, -1, X, -X ->
+ // select_cc setl[te] X, 0, -X, X ->
+ // select_cc setlt X, 1, -X, X ->
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
- if (N1C && N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
- N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1) &&
- N2.getOperand(0) == N1 && N0.getValueType().isInteger()) {
+ if (N1C) {
+ ConstantSDNode *SubC = NULL;
+ if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
+ (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
+ N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
+ SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
+ else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
+ (N1C->isOne() && CC == ISD::SETLT)) &&
+ N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
+ SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));
+
EVT XType = N0.getValueType();
- SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType, N0,
- DAG.getConstant(XType.getSizeInBits()-1,
- getShiftAmountTy()));
- SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(), XType,
- N0, Shift);
- AddToWorkList(Shift.getNode());
- AddToWorkList(Add.getNode());
- return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
- }
- // Check to see if this is an integer abs. select_cc setgt X, -1, X, -X ->
- // Y = sra (X, size(X)-1); xor (add (X, Y), Y)
- if (N1C && N1C->isAllOnesValue() && CC == ISD::SETGT &&
- N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1)) {
- if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
- EVT XType = N0.getValueType();
- if (SubC->isNullValue() && XType.isInteger()) {
- SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
- N0,
- DAG.getConstant(XType.getSizeInBits()-1,
- getShiftAmountTy()));
- SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
- XType, N0, Shift);
- AddToWorkList(Shift.getNode());
- AddToWorkList(Add.getNode());
- return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
- }
+ if (SubC && SubC->isNullValue() && XType.isInteger()) {
+ SDValue Shift = DAG.getNode(ISD::SRA, N0.getDebugLoc(), XType,
+ N0,
+ DAG.getConstant(XType.getSizeInBits()-1,
+ getShiftAmountTy()));
+ SDValue Add = DAG.getNode(ISD::ADD, N0.getDebugLoc(),
+ XType, N0, Shift);
+ AddToWorkList(Shift.getNode());
+ AddToWorkList(Add.getNode());
+ return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
}
}