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[DAGCombiner] reduce code duplication in visitXOR; NFC 

llvm-svn: 347278
This commit is contained in:
Sanjay Patel 2018-11-20 00:51:45 +00:00
parent 38b12f5e70
commit a36c444471
1 changed files with 29 additions and 32 deletions
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61
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -6039,8 +6039,9 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
}
// fold (xor undef, undef) -> 0. This is a common idiom (misuse).
SDLoc DL(N);
if (N0.isUndef() && N1.isUndef())
return DAG.getConstant(0, SDLoc(N), VT);
return DAG.getConstant(0, DL, VT);
// fold (xor x, undef) -> undef
if (N0.isUndef())
return N0;
@ -6050,11 +6051,11 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
if (N0C && N1C)
return DAG.FoldConstantArithmetic(ISD::XOR, SDLoc(N), VT, N0C, N1C);
return DAG.FoldConstantArithmetic(ISD::XOR, DL, VT, N0C, N1C);
// canonicalize constant to RHS
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
!DAG.isConstantIntBuildVectorOrConstantInt(N1))
return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
return DAG.getNode(ISD::XOR, DL, VT, N1, N0);
// fold (xor x, 0) -> x
if (isNullConstant(N1))
return N0;
@ -6063,19 +6064,18 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
return NewSel;
// reassociate xor
if (SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1, N->getFlags()))
if (SDValue RXOR = ReassociateOps(ISD::XOR, DL, N0, N1, N->getFlags()))
return RXOR;
// fold !(x cc y) -> (x !cc y)
unsigned N0Opcode = N0.getOpcode();
SDValue LHS, RHS, CC;
if (TLI.isConstTrueVal(N1.getNode()) && isSetCCEquivalent(N0, LHS, RHS, CC)) {
bool isInt = LHS.getValueType().isInteger();
ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
isInt);
LHS.getValueType().isInteger());
if (!LegalOperations ||
TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
switch (N0.getOpcode()) {
switch (N0Opcode) {
default:
llvm_unreachable("Unhandled SetCC Equivalent!");
case ISD::SETCC:
@ -6088,54 +6088,52 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
}
// fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
if (isOneConstant(N1) && N0.getOpcode() == ISD::ZERO_EXTEND &&
N0.getNode()->hasOneUse() &&
if (isOneConstant(N1) && N0Opcode == ISD::ZERO_EXTEND && N0.hasOneUse() &&
isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
SDValue V = N0.getOperand(0);
SDLoc DL(N0);
V = DAG.getNode(ISD::XOR, DL, V.getValueType(), V,
DAG.getConstant(1, DL, V.getValueType()));
SDLoc DL0(N0);
V = DAG.getNode(ISD::XOR, DL0, V.getValueType(), V,
DAG.getConstant(1, DL0, V.getValueType()));
AddToWorklist(V.getNode());
return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
return DAG.getNode(ISD::ZERO_EXTEND, DL, VT, V);
}
// fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
if (isOneConstant(N1) && VT == MVT::i1 && N0.hasOneUse() &&
(N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
(N0Opcode == ISD::OR || N0Opcode == ISD::AND)) {
SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
unsigned NewOpcode = N0Opcode == ISD::AND ? ISD::OR : ISD::AND;
LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
return DAG.getNode(NewOpcode, DL, VT, LHS, RHS);
}
}
// fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
if (isAllOnesConstant(N1) && N0.hasOneUse() &&
(N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
(N0Opcode == ISD::OR || N0Opcode == ISD::AND)) {
SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
unsigned NewOpcode = N0Opcode == ISD::AND ? ISD::OR : ISD::AND;
LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
return DAG.getNode(NewOpcode, DL, VT, LHS, RHS);
}
}
// fold (xor (and x, y), y) -> (and (not x), y)
if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
N0->getOperand(1) == N1) {
SDValue X = N0->getOperand(0);
if (N0Opcode == ISD::AND && N0.hasOneUse() && N0->getOperand(1) == N1) {
SDValue X = N0.getOperand(0);
SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
AddToWorklist(NotX.getNode());
return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
return DAG.getNode(ISD::AND, DL, VT, NotX, N1);
}
// fold Y = sra (X, size(X)-1); xor (add (X, Y), Y) -> (abs X)
if (TLI.isOperationLegalOrCustom(ISD::ABS, VT)) {
SDValue A = N0.getOpcode() == ISD::ADD ? N0 : N1;
SDValue S = N0.getOpcode() == ISD::SRA ? N0 : N1;
SDValue A = N0Opcode == ISD::ADD ? N0 : N1;
SDValue S = N0Opcode == ISD::SRA ? N0 : N1;
if (A.getOpcode() == ISD::ADD && S.getOpcode() == ISD::SRA) {
SDValue A0 = A.getOperand(0), A1 = A.getOperand(1);
SDValue S0 = S.getOperand(0);
@ -6143,14 +6141,14 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
unsigned OpSizeInBits = VT.getScalarSizeInBits();
if (ConstantSDNode *C = isConstOrConstSplat(S.getOperand(1)))
if (C->getAPIntValue() == (OpSizeInBits - 1))
return DAG.getNode(ISD::ABS, SDLoc(N), VT, S0);
return DAG.getNode(ISD::ABS, DL, VT, S0);
}
}
}
// fold (xor x, x) -> 0
if (N0 == N1)
return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations);
return tryFoldToZero(DL, TLI, VT, DAG, LegalOperations);
// fold (xor (shl 1, x), -1) -> (rotl ~1, x)
// Here is a concrete example of this equivalence:
@ -6170,15 +6168,14 @@ SDValue DAGCombiner::visitXOR(SDNode *N) {
// consistent result.
// - Pushing the zero left requires shifting one bits in from the right.
// A rotate left of ~1 is a nice way of achieving the desired result.
if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT) && N0.getOpcode() == ISD::SHL
&& isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0))) {
SDLoc DL(N);
if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT) && N0Opcode == ISD::SHL &&
isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0))) {
return DAG.getNode(ISD::ROTL, DL, VT, DAG.getConstant(~1, DL, VT),
N0.getOperand(1));
}
// Simplify: xor (op x...), (op y...) -> (op (xor x, y))
if (N0.getOpcode() == N1.getOpcode())
if (N0Opcode == N1.getOpcode())
if (SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N))
return Tmp;