SelectionDAG: Try to expand all condition codes using getCCSwappedOperands()
This is useful for targets like R600, which only support GT, GE, NE, and EQ
condition codes as it removes the need to handle unsupported condition
codes in target specific code.
There are no tests with this commit, but R600 has been updated to take
advantage of this new feature, so its existing selectcc tests are now
testing the swapped operands path.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191601 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index c58b8fd..f6406b2 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1615,8 +1615,13 @@
// Nothing to do.
break;
case TargetLowering::Expand: {
+ ISD::CondCode InvCC = ISD::getSetCCSwappedOperands(CCCode);
+ if (TLI.isCondCodeLegal(InvCC, OpVT)) {
+ std::swap(LHS, RHS);
+ CC = DAG.getCondCode(InvCC);
+ return true;
+ }
ISD::CondCode CC1 = ISD::SETCC_INVALID, CC2 = ISD::SETCC_INVALID;
- ISD::CondCode InvCC = ISD::SETCC_INVALID;
unsigned Opc = 0;
switch (CCCode) {
default: llvm_unreachable("Don't know how to expand this condition!");
@@ -1658,15 +1663,9 @@
case ISD::SETLT:
case ISD::SETNE:
case ISD::SETEQ:
- InvCC = ISD::getSetCCSwappedOperands(CCCode);
- if (TLI.getCondCodeAction(InvCC, OpVT) == TargetLowering::Expand) {
- // We only support using the inverted operation and not a
- // different manner of supporting expanding these cases.
- llvm_unreachable("Don't know how to expand this condition!");
- }
- std::swap(LHS, RHS);
- CC = DAG.getCondCode(InvCC);
- return true;
+ // We only support using the inverted operation, which is computed above
+ // and not a different manner of supporting expanding these cases.
+ llvm_unreachable("Don't know how to expand this condition!");
}
SDValue SetCC1, SetCC2;
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 25f6aac..b96c4b1 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1645,7 +1645,12 @@
}
} else {
// Ensure that the constant occurs on the RHS.
- return getSetCC(dl, VT, N2, N1, ISD::getSetCCSwappedOperands(Cond));
+ ISD::CondCode SwappedCond = ISD::getSetCCSwappedOperands(Cond);
+ MVT CompVT = N1.getValueType().getSimpleVT();
+ if (!TM.getTargetLowering()->isCondCodeLegal(SwappedCond, CompVT))
+ return SDValue();
+
+ return getSetCC(dl, VT, N2, N1, SwappedCond);
}
}
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 3881b0e..91276af 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1089,8 +1089,11 @@
// Ensure that the constant occurs on the RHS, and fold constant
// comparisons.
- if (isa<ConstantSDNode>(N0.getNode()))
- return DAG.getSetCC(dl, VT, N1, N0, ISD::getSetCCSwappedOperands(Cond));
+ ISD::CondCode SwappedCC = ISD::getSetCCSwappedOperands(Cond);
+ if (isa<ConstantSDNode>(N0.getNode()) &&
+ (DCI.isBeforeLegalizeOps() ||
+ isCondCodeLegal(SwappedCC, N0.getSimpleValueType())))
+ return DAG.getSetCC(dl, VT, N1, N0, SwappedCC);
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode())) {
const APInt &C1 = N1C->getAPIntValue();
@@ -1330,7 +1333,9 @@
ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
CC = ISD::getSetCCInverse(CC,
N0.getOperand(0).getValueType().isInteger());
- return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
+ if (DCI.isBeforeLegalizeOps() ||
+ isCondCodeLegal(CC, N0.getOperand(0).getSimpleValueType()))
+ return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
}
if ((N0.getOpcode() == ISD::XOR ||
@@ -1767,16 +1772,22 @@
if (N0.getOperand(0) == N1 || N0.getOperand(1) == N1) {
if (ValueHasExactlyOneBitSet(N1, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
- SDValue Zero = DAG.getConstant(0, N1.getValueType());
- return DAG.getSetCC(dl, VT, N0, Zero, Cond);
+ if (DCI.isBeforeLegalizeOps() ||
+ isCondCodeLegal(Cond, N0.getSimpleValueType())) {
+ SDValue Zero = DAG.getConstant(0, N1.getValueType());
+ return DAG.getSetCC(dl, VT, N0, Zero, Cond);
+ }
}
}
if (N1.getOpcode() == ISD::AND)
if (N1.getOperand(0) == N0 || N1.getOperand(1) == N0) {
if (ValueHasExactlyOneBitSet(N0, DAG)) {
Cond = ISD::getSetCCInverse(Cond, /*isInteger=*/true);
- SDValue Zero = DAG.getConstant(0, N0.getValueType());
- return DAG.getSetCC(dl, VT, N1, Zero, Cond);
+ if (DCI.isBeforeLegalizeOps() ||
+ isCondCodeLegal(Cond, N1.getSimpleValueType())) {
+ SDValue Zero = DAG.getConstant(0, N0.getValueType());
+ return DAG.getSetCC(dl, VT, N1, Zero, Cond);
+ }
}
}
}