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Move some Legalize functionality over to the DAGCombiner where it belongs. 

Kill some dead code.

llvm-svn: 23706
This commit is contained in:
Nate Begeman 2005-10-13 03:11:28 +00:00
parent b96e50ccbd
commit 02b23c6065
3 changed files with 79 additions and 149 deletions
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74
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
View File

@ -451,6 +451,9 @@ SDOperand DAGCombiner::visit(SDNode *N) {
}
SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
std::vector<SDOperand> Ops;
bool Changed = false;
// If the token factor has two operands and one is the entry token, replace
// the token factor with the other operand.
if (N->getNumOperands() == 2) {
@ -459,6 +462,19 @@ SDOperand DAGCombiner::visitTokenFactor(SDNode *N) {
if (N->getOperand(1).getOpcode() == ISD::EntryToken)
return N->getOperand(0);
}
// fold (tokenfactor (tokenfactor)) -> tokenfactor
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
SDOperand Op = N->getOperand(i);
if (Op.getOpcode() == ISD::TokenFactor && Op.hasOneUse()) {
Changed = true;
for (unsigned j = 0, e = Op.getNumOperands(); j != e; ++j)
Ops.push_back(Op.getOperand(j));
} else {
Ops.push_back(Op);
}
}
if (Changed)
return DAG.getNode(ISD::TokenFactor, MVT::Other, Ops);
return SDOperand();
}
@ -782,6 +798,40 @@ SDOperand DAGCombiner::visitAND(SDNode *N) {
WorkList.push_back(ANDNode.Val);
return DAG.getNode(N0.getOpcode(), VT, ANDNode, N0.getOperand(1));
}
// fold (zext_inreg (extload x)) -> (zextload x)
if (N1C && N0.getOpcode() == ISD::EXTLOAD) {
MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
// If the type of the zext_inreg and the extload match, and we're running
// before Legalize, or the resulting zextload is legal on the target, then
// go ahead and do the fold.
if ((N1C->getValue() == (1ULL << MVT::getSizeInBits(EVT))-1) &&
(!AfterLegalize ||
TargetLowering::Legal == TLI.getOperationAction(ISD::ZEXTLOAD, EVT))) {
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
N0.getOperand(1), N0.getOperand(2),
EVT);
CombineTo(N0.Val, ExtLoad, ExtLoad.getOperand(0));
WorkList.push_back(N);
return SDOperand();
}
}
// fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
if (N1C && N0.getOpcode() == ISD::SEXTLOAD && N0.Val->hasNUsesOfValue(1, 0)) {
MVT::ValueType EVT = cast<VTSDNode>(N0.getOperand(3))->getVT();
// If the type of the zext_inreg and the extload match, and we're running
// before Legalize, or the resulting zextload is legal on the target, then
// go ahead and do the fold.
if ((N1C->getValue() == (1ULL << MVT::getSizeInBits(EVT))-1) &&
(!AfterLegalize ||
TargetLowering::Legal == TLI.getOperationAction(ISD::ZEXTLOAD, EVT))) {
SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, N0.getOperand(0),
N0.getOperand(1), N0.getOperand(2),
EVT);
CombineTo(N0.Val, ExtLoad, ExtLoad.getOperand(0));
WorkList.push_back(N);
return SDOperand();
}
}
return SDOperand();
}
@ -1272,6 +1322,30 @@ SDOperand DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
return DAG.getNode(ISD::SRA, N0.getValueType(), N0.getOperand(0),
N0.getOperand(1));
}
// fold (sext_inreg (extload x)) -> (sextload x)
if (N0.getOpcode() == ISD::EXTLOAD &&
EVT == cast<VTSDNode>(N0.getOperand(3))->getVT() &&
(!AfterLegalize ||
(TargetLowering::Legal == TLI.getOperationAction(ISD::SEXTLOAD, EVT)))) {
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
N0.getOperand(1), N0.getOperand(2),
EVT);
CombineTo(N0.Val, ExtLoad, ExtLoad.getOperand(0));
WorkList.push_back(N);
return SDOperand();
}
// fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
if (N0.getOpcode() == ISD::ZEXTLOAD && N0.Val->hasNUsesOfValue(1, 0) &&
EVT == cast<VTSDNode>(N0.getOperand(3))->getVT() &&
(!AfterLegalize ||
(TargetLowering::Legal == TLI.getOperationAction(ISD::SEXTLOAD, EVT)))) {
SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, N0.getOperand(0),
N0.getOperand(1), N0.getOperand(2),
EVT);
CombineTo(N0.Val, ExtLoad, ExtLoad.getOperand(0));
WorkList.push_back(N);
return SDOperand();
}
return SDOperand();
}

23
llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
View File

@ -635,18 +635,11 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
case ISD::TokenFactor: {
std::vector<SDOperand> Ops;
bool Changed = false;
// Legalize the operands
for (unsigned i = 0, e = Node->getNumOperands(); i != e; ++i) {
SDOperand Op = Node->getOperand(i);
// Fold single-use TokenFactor nodes into this token factor as we go.
// FIXME: This is something that the DAGCombiner should do!!
if (Op.getOpcode() == ISD::TokenFactor && Op.hasOneUse()) {
Changed = true;
for (unsigned j = 0, e = Op.getNumOperands(); j != e; ++j)
Ops.push_back(LegalizeOp(Op.getOperand(j)));
} else {
Ops.push_back(LegalizeOp(Op)); // Legalize the operands
Changed |= Ops[i] != Op;
}
Ops.push_back(LegalizeOp(Op));
Changed |= Ops[i] != Op;
}
if (Changed)
Result = DAG.getNode(ISD::TokenFactor, MVT::Other, Ops);
@ -2352,14 +2345,8 @@ SDOperand SelectionDAGLegalize::PromoteOp(SDOperand Op) {
case ISD::LOAD:
Tmp1 = LegalizeOp(Node->getOperand(0)); // Legalize the chain.
Tmp2 = LegalizeOp(Node->getOperand(1)); // Legalize the pointer.
// FIXME: When the DAG combiner exists, change this to use EXTLOAD!
if (MVT::isInteger(NVT))
Result = DAG.getExtLoad(ISD::ZEXTLOAD, NVT, Tmp1, Tmp2,
Node->getOperand(2), VT);
else
Result = DAG.getExtLoad(ISD::EXTLOAD, NVT, Tmp1, Tmp2,
Node->getOperand(2), VT);
Result = DAG.getExtLoad(ISD::EXTLOAD, NVT, Tmp1, Tmp2,
Node->getOperand(2), VT);
// Remember that we legalized the chain.
AddLegalizedOperand(Op.getValue(1), Result.getValue(1));
break;

131
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -779,134 +779,6 @@ SDOperand SelectionDAG::SimplifySetCC(MVT::ValueType VT, SDOperand N1,
return SDOperand();
}
SDOperand SelectionDAG::SimplifySelectCC(SDOperand N1, SDOperand N2,
SDOperand N3, SDOperand N4,
ISD::CondCode CC) {
MVT::ValueType VT = N3.getValueType();
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
ConstantSDNode *N4C = dyn_cast<ConstantSDNode>(N4.Val);
// Check to see if we can simplify the select into an fabs node
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N2)) {
// Allow either -0.0 or 0.0
if (CFP->getValue() == 0.0) {
// select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
N1 == N3 && N4.getOpcode() == ISD::FNEG &&
N1 == N4.getOperand(0))
return getNode(ISD::FABS, VT, N1);
// select (setl[te] X, +/-0.0), fneg(X), X -> fabs
if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
N1 == N4 && N3.getOpcode() == ISD::FNEG &&
N3.getOperand(0) == N4)
return getNode(ISD::FABS, VT, N4);
}
}
// check to see if we're select_cc'ing a select_cc.
// this allows us to turn:
// select_cc set[eq,ne] (select_cc cc, lhs, rhs, 1, 0), 0, true, false ->
// select_cc cc, lhs, rhs, true, false
if ((N1C && N1C->isNullValue() && N2.getOpcode() == ISD::SELECT_CC) ||
(N2C && N2C->isNullValue() && N1.getOpcode() == ISD::SELECT_CC) &&
(CC == ISD::SETEQ || CC == ISD::SETNE)) {
SDOperand SCC = N1C ? N2 : N1;
ConstantSDNode *SCCT = dyn_cast<ConstantSDNode>(SCC.getOperand(2));
ConstantSDNode *SCCF = dyn_cast<ConstantSDNode>(SCC.getOperand(3));
if (SCCT && SCCF && SCCF->isNullValue() && SCCT->getValue() == 1ULL) {
if (CC == ISD::SETEQ) std::swap(N3, N4);
return getNode(ISD::SELECT_CC, N3.getValueType(), SCC.getOperand(0),
SCC.getOperand(1), N3, N4, SCC.getOperand(4));
}
}
// Check to see if we can perform the "gzip trick", transforming
// select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
if (N2C && N2C->isNullValue() && N4C && N4C->isNullValue() &&
MVT::isInteger(N1.getValueType()) &&
MVT::isInteger(N3.getValueType()) && CC == ISD::SETLT) {
MVT::ValueType XType = N1.getValueType();
MVT::ValueType AType = N3.getValueType();
if (XType >= AType) {
// and (sra X, size(X)-1, A) -> "and (srl X, C2), A" iff A is a
// single-bit constant. FIXME: remove once the dag combiner
// exists.
if (N3C && ((N3C->getValue() & (N3C->getValue()-1)) == 0)) {
unsigned ShCtV = Log2_64(N3C->getValue());
ShCtV = MVT::getSizeInBits(XType)-ShCtV-1;
SDOperand ShCt = getConstant(ShCtV, TLI.getShiftAmountTy());
SDOperand Shift = getNode(ISD::SRL, XType, N1, ShCt);
if (XType > AType)
Shift = getNode(ISD::TRUNCATE, AType, Shift);
return getNode(ISD::AND, AType, Shift, N3);
}
SDOperand Shift = getNode(ISD::SRA, XType, N1,
getConstant(MVT::getSizeInBits(XType)-1,
TLI.getShiftAmountTy()));
if (XType > AType)
Shift = getNode(ISD::TRUNCATE, AType, Shift);
return getNode(ISD::AND, AType, Shift, N3);
}
}
// Check to see if this is the equivalent of setcc
if (N4C && N4C->isNullValue() && N3C && (N3C->getValue() == 1ULL)) {
MVT::ValueType XType = N1.getValueType();
if (TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultTy())) {
SDOperand Res = getSetCC(TLI.getSetCCResultTy(), N1, N2, CC);
if (Res.getValueType() != VT)
Res = getNode(ISD::ZERO_EXTEND, VT, Res);
return Res;
}
// seteq X, 0 -> srl (ctlz X, log2(size(X)))
if (N2C && N2C->isNullValue() && CC == ISD::SETEQ &&
TLI.isOperationLegal(ISD::CTLZ, XType)) {
SDOperand Ctlz = getNode(ISD::CTLZ, XType, N1);
return getNode(ISD::SRL, XType, Ctlz,
getConstant(Log2_32(MVT::getSizeInBits(XType)),
TLI.getShiftAmountTy()));
}
// setgt X, 0 -> srl (and (-X, ~X), size(X)-1)
if (N2C && N2C->isNullValue() && CC == ISD::SETGT) {
SDOperand NegN1 = getNode(ISD::SUB, XType, getConstant(0, XType), N1);
SDOperand NotN1 = getNode(ISD::XOR, XType, N1, getConstant(~0ULL, XType));
return getNode(ISD::SRL, XType, getNode(ISD::AND, XType, NegN1, NotN1),
getConstant(MVT::getSizeInBits(XType)-1,
TLI.getShiftAmountTy()));
}
// setgt X, -1 -> xor (srl (X, size(X)-1), 1)
if (N2C && N2C->isAllOnesValue() && CC == ISD::SETGT) {
SDOperand Sign = getNode(ISD::SRL, XType, N1,
getConstant(MVT::getSizeInBits(XType)-1,
TLI.getShiftAmountTy()));
return getNode(ISD::XOR, XType, Sign, getConstant(1, XType));
}
}
// Check to see if this is an integer abs. select_cc setl[te] X, 0, -X, X ->
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
if (N2C && N2C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE) &&
N1 == N4 && N3.getOpcode() == ISD::SUB && N1 == N3.getOperand(1)) {
if (ConstantSDNode *SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0))) {
MVT::ValueType XType = N1.getValueType();
if (SubC->isNullValue() && MVT::isInteger(XType)) {
SDOperand Shift = getNode(ISD::SRA, XType, N1,
getConstant(MVT::getSizeInBits(XType)-1,
TLI.getShiftAmountTy()));
return getNode(ISD::XOR, XType, getNode(ISD::ADD, XType, N1, Shift),
Shift);
}
}
}
// Could not fold it.
return SDOperand();
}
/// getNode - Gets or creates the specified node.
///
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) {
@ -1370,9 +1242,6 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
"True and False arms of SelectCC must have same type!");
assert(Ops[2].getValueType() == VT &&
"select_cc node must be of same type as true and false value!");
SDOperand Simp = SimplifySelectCC(Ops[0], Ops[1], Ops[2], Ops[3],
cast<CondCodeSDNode>(Ops[4])->get());
if (Simp.Val) return Simp;
break;
}
case ISD::BR_CC: {