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[DAGCombiner] split trunc from extend in hoistLogicOpWithSameOpcodeHands; NFC 

This duplicates several shared checks, but we need to split
this up to fix underlying bugs in smaller steps.

llvm-svn: 348627
This commit is contained in:
Sanjay Patel 2018-12-07 18:51:08 +00:00
parent 9b8fdab26c
commit bc47ff86fe
1 changed files with 48 additions and 33 deletions
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81
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -3729,39 +3729,54 @@ SDValue DAGCombiner::hoistLogicOpWithSameOpcodeHands(SDNode *N) {
SDValue Y = N1.getOperand(0);
EVT XVT = X.getValueType();
SDLoc DL(N);
switch (HandOpcode) {
case ISD::ANY_EXTEND:
case ISD::TRUNCATE:
case ISD::ZERO_EXTEND:
case ISD::SIGN_EXTEND:
// If both operands have other uses, this transform would create extra
// instructions without eliminating anything.
if (!N0.hasOneUse() && !N1.hasOneUse())
return SDValue();
// We need matching integer source types.
// Do not hoist logic op inside of a vector extend, since it may combine
// into a vsetcc.
// TODO: Should the vector check apply to truncate though?
if (VT.isVector() || XVT != Y.getValueType())
return SDValue();
// Don't create an illegal op during or after legalization.
if (LegalOperations && !TLI.isOperationLegal(LogicOpcode, XVT))
return SDValue();
// Avoid infinite looping with PromoteIntBinOp.
if (HandOpcode == ISD::ANY_EXTEND && LegalTypes &&
!TLI.isTypeDesirableForOp(LogicOpcode, XVT))
return SDValue();
// Be extra careful sinking truncate.
// TODO: Should we apply desirable/legal constraints to all opcodes?
if (HandOpcode == ISD::TRUNCATE) {
if (TLI.isZExtFree(VT, XVT) && TLI.isTruncateFree(XVT, VT))
return SDValue();
if (!TLI.isTypeLegal(XVT))
return SDValue();
}
// logic_op (hand_op X), (hand_op Y) --> hand_op (logic_op X, Y)
SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y);
return DAG.getNode(HandOpcode, DL, VT, Logic);
if (HandOpcode == ISD::ANY_EXTEND || HandOpcode == ISD::ZERO_EXTEND ||
HandOpcode == ISD::SIGN_EXTEND) {
// If both operands have other uses, this transform would create extra
// instructions without eliminating anything.
if (!N0.hasOneUse() && !N1.hasOneUse())
return SDValue();
// We need matching integer source types.
// Do not hoist logic op inside of a vector extend, since it may combine
// into a vsetcc.
// TODO: Should the vector check apply to truncate though?
if (VT.isVector() || XVT != Y.getValueType())
return SDValue();
// Don't create an illegal op during or after legalization.
if (LegalOperations && !TLI.isOperationLegal(LogicOpcode, XVT))
return SDValue();
// Avoid infinite looping with PromoteIntBinOp.
// TODO: Should we apply desirable/legal constraints to all opcodes?
if (HandOpcode == ISD::ANY_EXTEND && LegalTypes &&
!TLI.isTypeDesirableForOp(LogicOpcode, XVT))
return SDValue();
// logic_op (hand_op X), (hand_op Y) --> hand_op (logic_op X, Y)
SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y);
return DAG.getNode(HandOpcode, DL, VT, Logic);
}
// logic_op (truncate x), (truncate y) --> truncate (logic_op x, y)
if (HandOpcode == ISD::TRUNCATE) {
// If both operands have other uses, this transform would create extra
// instructions without eliminating anything.
if (!N0.hasOneUse() && !N1.hasOneUse())
return SDValue();
// We need matching integer source types.
// Do not hoist logic op inside of a vector extend, since it may combine
// into a vsetcc.
// TODO: Should the vector check apply to truncate though?
if (VT.isVector() || XVT != Y.getValueType())
return SDValue();
// Don't create an illegal op during or after legalization.
if (LegalOperations && !TLI.isOperationLegal(LogicOpcode, XVT))
return SDValue();
// Be extra careful sinking truncate. If it's free, there's no benefit in
// widening a binop. Also, don't create a logic op on an illegal type.
if (TLI.isZExtFree(VT, XVT) && TLI.isTruncateFree(XVT, VT))
return SDValue();
if (!TLI.isTypeLegal(XVT))
return SDValue();
SDValue Logic = DAG.getNode(LogicOpcode, DL, XVT, X, Y);
return DAG.getNode(HandOpcode, DL, VT, Logic);
}
// For binops SHL/SRL/SRA/AND: