//
// This pass combines dag nodes to form fewer, simpler DAG nodes. It can be run
// both before and after the DAG is legalized.
-//
-// FIXME: Missing folds
-// sdiv, udiv, srem, urem (X, const) where X is an integer can be expanded into
-// a sequence of multiplies, shifts, and adds. This should be controlled by
-// some kind of hint from the target that int div is expensive.
-// various folds of mulh[s,u] by constants such as -1, powers of 2, etc.
-//
-// FIXME: select C, pow2, pow2 -> something smart
-// FIXME: trunc(select X, Y, Z) -> select X, trunc(Y), trunc(Z)
-// FIXME: Dead stores -> nuke
-// FIXME: shr X, (and Y,31) -> shr X, Y (TRICKY!)
-// FIXME: mul (x, const) -> shifts + adds
-// FIXME: undef values
-// FIXME: divide by zero is currently left unfolded. do we want to turn this
-// into an undef?
-// FIXME: select ne (select cc, 1, 0), 0, true, false -> select cc, true, false
//
//===----------------------------------------------------------------------===//
WorkList.end());
}
+ /// visit - call the node-specific routine that knows how to fold each
+ /// particular type of node.
+ SDOperand visit(SDNode *N);
+
public:
/// AddToWorkList - Add to the work list making sure it's instance is at the
/// the back (next to be processed.)
/// SimplifyDemandedBits - Check the specified integer node value to see if
/// it can be simplified or if things it uses can be simplified by bit
/// propagation. If so, return true.
- bool SimplifyDemandedBits(SDOperand Op) {
- TargetLowering::TargetLoweringOpt TLO(DAG);
+ bool SimplifyDemandedBits(SDOperand Op, uint64_t Demanded = ~0ULL) {
+ TargetLowering::TargetLoweringOpt TLO(DAG, AfterLegalize);
uint64_t KnownZero, KnownOne;
- uint64_t Demanded = MVT::getIntVTBitMask(Op.getValueType());
+ Demanded &= MVT::getIntVTBitMask(Op.getValueType());
if (!TLI.SimplifyDemandedBits(Op, Demanded, KnownZero, KnownOne, TLO))
return false;
DOUT << '\n';
std::vector<SDNode*> NowDead;
- DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, NowDead);
+ DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &NowDead);
// Push the new node and any (possibly new) users onto the worklist.
AddToWorkList(TLO.New.Val);
bool CombineToPostIndexedLoadStore(SDNode *N);
- /// visit - call the node-specific routine that knows how to fold each
- /// particular type of node.
- SDOperand visit(SDNode *N);
+ /// combine - call the node-specific routine that knows how to fold each
+ /// particular type of node. If that doesn't do anything, try the
+ /// target-specific DAG combines.
+ SDOperand combine(SDNode *N);
// Visitation implementation - Implement dag node combining for different
// node types. The semantics are as follows:
SDOperand visitUREM(SDNode *N);
SDOperand visitMULHU(SDNode *N);
SDOperand visitMULHS(SDNode *N);
+ SDOperand visitSMUL_LOHI(SDNode *N);
+ SDOperand visitUMUL_LOHI(SDNode *N);
+ SDOperand visitSDIVREM(SDNode *N);
+ SDOperand visitUDIVREM(SDNode *N);
SDOperand visitAND(SDNode *N);
SDOperand visitOR(SDNode *N);
SDOperand visitXOR(SDNode *N);
SDOperand XformToShuffleWithZero(SDNode *N);
SDOperand ReassociateOps(unsigned Opc, SDOperand LHS, SDOperand RHS);
+ SDOperand visitShiftByConstant(SDNode *N, unsigned Amt);
+
bool SimplifySelectOps(SDNode *SELECT, SDOperand LHS, SDOperand RHS);
SDOperand SimplifyBinOpWithSameOpcodeHands(SDNode *N);
SDOperand SimplifySelect(SDOperand N0, SDOperand N1, SDOperand N2);
bool NotExtCompare = false);
SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N0, SDOperand N1,
ISD::CondCode Cond, bool foldBooleans = true);
+ bool SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp, unsigned HiOp);
SDOperand ConstantFoldBIT_CONVERTofBUILD_VECTOR(SDNode *, MVT::ValueType);
SDOperand BuildSDIV(SDNode *N);
SDOperand BuildUDIV(SDNode *N);
SDNode *MatchRotate(SDOperand LHS, SDOperand RHS);
SDOperand ReduceLoadWidth(SDNode *N);
+ SDOperand GetDemandedBits(SDOperand V, uint64_t Mask);
+
/// GatherAllAliases - Walk up chain skipping non-aliasing memory nodes,
/// looking for aliasing nodes and adding them to the Aliases vector.
void GatherAllAliases(SDNode *N, SDOperand OriginalChain,
/// specified expression for the same cost as the expression itself, or 2 if we
/// can compute the negated form more cheaply than the expression itself.
static char isNegatibleForFree(SDOperand Op, unsigned Depth = 0) {
+ // No compile time optimizations on this type.
+ if (Op.getValueType() == MVT::ppcf128)
+ return 0;
+
// fneg is removable even if it has multiple uses.
if (Op.getOpcode() == ISD::FNEG) return 2;
// done. Set it to null to avoid confusion.
DAG.setRoot(SDOperand());
- /// DagCombineInfo - Expose the DAG combiner to the target combiner impls.
- TargetLowering::DAGCombinerInfo
- DagCombineInfo(DAG, !RunningAfterLegalize, false, this);
-
// while the worklist isn't empty, inspect the node on the end of it and
// try and combine it.
while (!WorkList.empty()) {
continue;
}
- SDOperand RV = visit(N);
-
- // If nothing happened, try a target-specific DAG combine.
- if (RV.Val == 0) {
- assert(N->getOpcode() != ISD::DELETED_NODE &&
- "Node was deleted but visit returned NULL!");
- if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
- TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode()))
- RV = TLI.PerformDAGCombine(N, DagCombineInfo);
- }
+ SDOperand RV = combine(N);
if (RV.Val) {
++NodesCombined;
case ISD::UREM: return visitUREM(N);
case ISD::MULHU: return visitMULHU(N);
case ISD::MULHS: return visitMULHS(N);
+ case ISD::SMUL_LOHI: return visitSMUL_LOHI(N);
+ case ISD::UMUL_LOHI: return visitUMUL_LOHI(N);
+ case ISD::SDIVREM: return visitSDIVREM(N);
+ case ISD::UDIVREM: return visitUDIVREM(N);
case ISD::AND: return visitAND(N);
case ISD::OR: return visitOR(N);
case ISD::XOR: return visitXOR(N);
return SDOperand();
}
+SDOperand DAGCombiner::combine(SDNode *N) {
+
+ SDOperand RV = visit(N);
+
+ // If nothing happened, try a target-specific DAG combine.
+ if (RV.Val == 0) {
+ assert(N->getOpcode() != ISD::DELETED_NODE &&
+ "Node was deleted but visit returned NULL!");
+
+ if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
+ TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {
+
+ // Expose the DAG combiner to the target combiner impls.
+ TargetLowering::DAGCombinerInfo
+ DagCombineInfo(DAG, !AfterLegalize, false, this);
+
+ RV = TLI.PerformDAGCombine(N, DagCombineInfo);
+ }
+ }
+
+ return RV;
+}
+
/// getInputChainForNode - Given a node, return its input chain if it has one,
/// otherwise return a null sd operand.
static SDOperand getInputChainForNode(SDNode *N) {
DAG.MaskedValueIsZero(N0, SignBit))
return DAG.getNode(ISD::UREM, VT, N0, N1);
- // Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
- // the remainder operation.
+ // If X/C can be simplified by the division-by-constant logic, lower
+ // X%C to the equivalent of X-X/C*C.
if (N1C && !N1C->isNullValue()) {
SDOperand Div = DAG.getNode(ISD::SDIV, VT, N0, N1);
- SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
- SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
- AddToWorkList(Div.Val);
- AddToWorkList(Mul.Val);
- return Sub;
+ SDOperand OptimizedDiv = combine(Div.Val);
+ if (OptimizedDiv.Val && OptimizedDiv.Val != Div.Val) {
+ SDOperand Mul = DAG.getNode(ISD::MUL, VT, OptimizedDiv, N1);
+ SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
+ AddToWorkList(Mul.Val);
+ return Sub;
+ }
}
// undef % X -> 0
}
}
- // Unconditionally lower X%C -> X-X/C*C. This allows the X/C logic to hack on
- // the remainder operation.
+ // If X/C can be simplified by the division-by-constant logic, lower
+ // X%C to the equivalent of X-X/C*C.
if (N1C && !N1C->isNullValue()) {
SDOperand Div = DAG.getNode(ISD::UDIV, VT, N0, N1);
- SDOperand Mul = DAG.getNode(ISD::MUL, VT, Div, N1);
- SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
- AddToWorkList(Div.Val);
- AddToWorkList(Mul.Val);
- return Sub;
+ SDOperand OptimizedDiv = combine(Div.Val);
+ if (OptimizedDiv.Val && OptimizedDiv.Val != Div.Val) {
+ SDOperand Mul = DAG.getNode(ISD::MUL, VT, OptimizedDiv, N1);
+ SDOperand Sub = DAG.getNode(ISD::SUB, VT, N0, Mul);
+ AddToWorkList(Mul.Val);
+ return Sub;
+ }
}
// undef % X -> 0
return SDOperand();
}
+/// SimplifyNodeWithTwoResults - Perform optimizations common to nodes that
+/// compute two values. LoOp and HiOp give the opcodes for the two computations
+/// that are being performed. Return true if a simplification was made.
+///
+bool DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N,
+ unsigned LoOp, unsigned HiOp) {
+ // If the high half is not needed, just compute the low half.
+ bool HiExists = N->hasAnyUseOfValue(1);
+ if (!HiExists &&
+ (!AfterLegalize ||
+ TLI.isOperationLegal(LoOp, N->getValueType(0)))) {
+ DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0),
+ DAG.getNode(LoOp, N->getValueType(0),
+ N->op_begin(),
+ N->getNumOperands()));
+ return true;
+ }
+
+ // If the low half is not needed, just compute the high half.
+ bool LoExists = N->hasAnyUseOfValue(0);
+ if (!LoExists &&
+ (!AfterLegalize ||
+ TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
+ DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1),
+ DAG.getNode(HiOp, N->getValueType(1),
+ N->op_begin(),
+ N->getNumOperands()));
+ return true;
+ }
+
+ // If both halves are used, return as it is.
+ if (LoExists && HiExists)
+ return false;
+
+ // If the two computed results can be simplified separately, separate them.
+ bool RetVal = false;
+ if (LoExists) {
+ SDOperand Lo = DAG.getNode(LoOp, N->getValueType(0),
+ N->op_begin(), N->getNumOperands());
+ SDOperand LoOpt = combine(Lo.Val);
+ if (LoOpt.Val && LoOpt != Lo &&
+ TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())) {
+ RetVal = true;
+ DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), LoOpt);
+ } else
+ DAG.DeleteNode(Lo.Val);
+ }
+
+ if (HiExists) {
+ SDOperand Hi = DAG.getNode(HiOp, N->getValueType(1),
+ N->op_begin(), N->getNumOperands());
+ SDOperand HiOpt = combine(Hi.Val);
+ if (HiOpt.Val && HiOpt != Hi &&
+ TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())) {
+ RetVal = true;
+ DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), HiOpt);
+ } else
+ DAG.DeleteNode(Hi.Val);
+ }
+
+ return RetVal;
+}
+
+SDOperand DAGCombiner::visitSMUL_LOHI(SDNode *N) {
+
+ if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS))
+ return SDOperand();
+
+ return SDOperand();
+}
+
+SDOperand DAGCombiner::visitUMUL_LOHI(SDNode *N) {
+
+ if (SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU))
+ return SDOperand();
+
+ return SDOperand();
+}
+
+SDOperand DAGCombiner::visitSDIVREM(SDNode *N) {
+
+ if (SimplifyNodeWithTwoResults(N, ISD::SDIV, ISD::SREM))
+ return SDOperand();
+
+ return SDOperand();
+}
+
+SDOperand DAGCombiner::visitUDIVREM(SDNode *N) {
+
+ if (SimplifyNodeWithTwoResults(N, ISD::UDIV, ISD::UREM))
+ return SDOperand();
+
+ return SDOperand();
+}
+
/// SimplifyBinOpWithSameOpcodeHands - If this is a binary operator with
/// two operands of the same opcode, try to simplify it.
SDOperand DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
// For big endian targets, we need to add an offset to the pointer to
// load the correct bytes. For little endian systems, we merely need to
// read fewer bytes from the same pointer.
- unsigned PtrOff =
- (MVT::getSizeInBits(LoadedVT) - MVT::getSizeInBits(EVT)) / 8;
+ unsigned LVTStoreBytes = MVT::getStoreSizeInBits(LoadedVT)/8;
+ unsigned EVTStoreBytes = MVT::getStoreSizeInBits(EVT)/8;
+ unsigned PtrOff = LVTStoreBytes - EVTStoreBytes;
+ unsigned Alignment = LN0->getAlignment();
SDOperand NewPtr = LN0->getBasePtr();
- if (!TLI.isLittleEndian())
+ if (!TLI.isLittleEndian()) {
NewPtr = DAG.getNode(ISD::ADD, PtrType, NewPtr,
DAG.getConstant(PtrOff, PtrType));
+ Alignment = MinAlign(Alignment, PtrOff);
+ }
AddToWorkList(NewPtr.Val);
SDOperand Load =
DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(), NewPtr,
LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
- LN0->isVolatile(), LN0->getAlignment());
+ LN0->isVolatile(), Alignment);
AddToWorkList(N);
CombineTo(N0.Val, Load, Load.getValue(1));
return SDOperand(N, 0); // Return N so it doesn't get rechecked!
N0.Val->hasOneUse() && isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
SDOperand V = N0.getOperand(0);
V = DAG.getNode(ISD::XOR, V.getValueType(), V,
- DAG.getConstant(V.getValueType(), 1));
+ DAG.getConstant(1, V.getValueType()));
AddToWorkList(V.Val);
return DAG.getNode(ISD::ZERO_EXTEND, VT, V);
}
return SDOperand();
}
+/// visitShiftByConstant - Handle transforms common to the three shifts, when
+/// the shift amount is a constant.
+SDOperand DAGCombiner::visitShiftByConstant(SDNode *N, unsigned Amt) {
+ SDNode *LHS = N->getOperand(0).Val;
+ if (!LHS->hasOneUse()) return SDOperand();
+
+ // We want to pull some binops through shifts, so that we have (and (shift))
+ // instead of (shift (and)), likewise for add, or, xor, etc. This sort of
+ // thing happens with address calculations, so it's important to canonicalize
+ // it.
+ bool HighBitSet = false; // Can we transform this if the high bit is set?
+
+ switch (LHS->getOpcode()) {
+ default: return SDOperand();
+ case ISD::OR:
+ case ISD::XOR:
+ HighBitSet = false; // We can only transform sra if the high bit is clear.
+ break;
+ case ISD::AND:
+ HighBitSet = true; // We can only transform sra if the high bit is set.
+ break;
+ case ISD::ADD:
+ if (N->getOpcode() != ISD::SHL)
+ return SDOperand(); // only shl(add) not sr[al](add).
+ HighBitSet = false; // We can only transform sra if the high bit is clear.
+ break;
+ }
+
+ // We require the RHS of the binop to be a constant as well.
+ ConstantSDNode *BinOpCst = dyn_cast<ConstantSDNode>(LHS->getOperand(1));
+ if (!BinOpCst) return SDOperand();
+
+
+ // FIXME: disable this for unless the input to the binop is a shift by a
+ // constant. If it is not a shift, it pessimizes some common cases like:
+ //
+ //void foo(int *X, int i) { X[i & 1235] = 1; }
+ //int bar(int *X, int i) { return X[i & 255]; }
+ SDNode *BinOpLHSVal = LHS->getOperand(0).Val;
+ if ((BinOpLHSVal->getOpcode() != ISD::SHL &&
+ BinOpLHSVal->getOpcode() != ISD::SRA &&
+ BinOpLHSVal->getOpcode() != ISD::SRL) ||
+ !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1)))
+ return SDOperand();
+
+ MVT::ValueType VT = N->getValueType(0);
+
+ // If this is a signed shift right, and the high bit is modified
+ // by the logical operation, do not perform the transformation.
+ // The highBitSet boolean indicates the value of the high bit of
+ // the constant which would cause it to be modified for this
+ // operation.
+ if (N->getOpcode() == ISD::SRA) {
+ uint64_t BinOpRHSSign = BinOpCst->getValue() >> MVT::getSizeInBits(VT)-1;
+ if ((bool)BinOpRHSSign != HighBitSet)
+ return SDOperand();
+ }
+
+ // Fold the constants, shifting the binop RHS by the shift amount.
+ SDOperand NewRHS = DAG.getNode(N->getOpcode(), N->getValueType(0),
+ LHS->getOperand(1), N->getOperand(1));
+
+ // Create the new shift.
+ SDOperand NewShift = DAG.getNode(N->getOpcode(), VT, LHS->getOperand(0),
+ N->getOperand(1));
+
+ // Create the new binop.
+ return DAG.getNode(LHS->getOpcode(), VT, NewShift, NewRHS);
+}
+
+
SDOperand DAGCombiner::visitSHL(SDNode *N) {
SDOperand N0 = N->getOperand(0);
SDOperand N1 = N->getOperand(1);
if (N1C && N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1))
return DAG.getNode(ISD::AND, VT, N0.getOperand(0),
DAG.getConstant(~0ULL << N1C->getValue(), VT));
- return SDOperand();
+
+ return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
}
SDOperand DAGCombiner::visitSRA(SDNode *N) {
// If the sign bit is known to be zero, switch this to a SRL.
if (DAG.MaskedValueIsZero(N0, MVT::getIntVTSignBit(VT)))
return DAG.getNode(ISD::SRL, VT, N0, N1);
- return SDOperand();
+
+ return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
}
SDOperand DAGCombiner::visitSRL(SDNode *N) {
if (N1C && SimplifyDemandedBits(SDOperand(N, 0)))
return SDOperand(N, 0);
- return SDOperand();
+ return N1C ? visitShiftByConstant(N, N1C->getValue()) : SDOperand();
}
SDOperand DAGCombiner::visitCTLZ(SDNode *N) {
return DAG.getNode(ISD::TRUNCATE, VT, XORNode);
}
// fold select C, 0, X -> ~C & X
- if (VT == VT0 && N1C && N1C->isNullValue()) {
+ if (VT == VT0 && VT == MVT::i1 && N1C && N1C->isNullValue()) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::AND, VT, XORNode, N2);
}
// fold select C, X, 1 -> ~C | X
- if (VT == VT0 && N2C && N2C->getValue() == 1) {
+ if (VT == VT0 && VT == MVT::i1 && N2C && N2C->getValue() == 1) {
SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT));
AddToWorkList(XORNode.Val);
return DAG.getNode(ISD::OR, VT, XORNode, N1);
cast<CondCodeSDNode>(N->getOperand(2))->get());
}
+// ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
+// "fold ({s|z}ext (load x)) -> ({s|z}ext (truncate ({s|z}extload x)))"
+// transformation. Returns true if extension are possible and the above
+// mentioned transformation is profitable.
+static bool ExtendUsesToFormExtLoad(SDNode *N, SDOperand N0,
+ unsigned ExtOpc,
+ SmallVector<SDNode*, 4> &ExtendNodes,
+ TargetLowering &TLI) {
+ bool HasCopyToRegUses = false;
+ bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
+ for (SDNode::use_iterator UI = N0.Val->use_begin(), UE = N0.Val->use_end();
+ UI != UE; ++UI) {
+ SDNode *User = *UI;
+ if (User == N)
+ continue;
+ // FIXME: Only extend SETCC N, N and SETCC N, c for now.
+ if (User->getOpcode() == ISD::SETCC) {
+ ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
+ if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
+ // Sign bits will be lost after a zext.
+ return false;
+ bool Add = false;
+ for (unsigned i = 0; i != 2; ++i) {
+ SDOperand UseOp = User->getOperand(i);
+ if (UseOp == N0)
+ continue;
+ if (!isa<ConstantSDNode>(UseOp))
+ return false;
+ Add = true;
+ }
+ if (Add)
+ ExtendNodes.push_back(User);
+ } else {
+ for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
+ SDOperand UseOp = User->getOperand(i);
+ if (UseOp == N0) {
+ // If truncate from extended type to original load type is free
+ // on this target, then it's ok to extend a CopyToReg.
+ if (isTruncFree && User->getOpcode() == ISD::CopyToReg)
+ HasCopyToRegUses = true;
+ else
+ return false;
+ }
+ }
+ }
+ }
+
+ if (HasCopyToRegUses) {
+ bool BothLiveOut = false;
+ for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
+ UI != UE; ++UI) {
+ SDNode *User = *UI;
+ for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
+ SDOperand UseOp = User->getOperand(i);
+ if (UseOp.Val == N && UseOp.ResNo == 0) {
+ BothLiveOut = true;
+ break;
+ }
+ }
+ }
+ if (BothLiveOut)
+ // Both unextended and extended values are live out. There had better be
+ // good a reason for the transformation.
+ return ExtendNodes.size();
+ }
+ return true;
+}
+
SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
SDOperand N0 = N->getOperand(0);
MVT::ValueType VT = N->getValueType(0);
}
// fold (sext (load x)) -> (sext (truncate (sextload x)))
- if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
+ if (ISD::isNON_EXTLoad(N0.Val) &&
(!AfterLegalize||TLI.isLoadXLegal(ISD::SEXTLOAD, N0.getValueType()))){
- LoadSDNode *LN0 = cast<LoadSDNode>(N0);
- SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
- LN0->getBasePtr(), LN0->getSrcValue(),
- LN0->getSrcValueOffset(),
- N0.getValueType(),
- LN0->isVolatile(),
- LN0->getAlignment());
- CombineTo(N, ExtLoad);
- CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
- ExtLoad.getValue(1));
- return SDOperand(N, 0); // Return N so it doesn't get rechecked!
+ bool DoXform = true;
+ SmallVector<SDNode*, 4> SetCCs;
+ if (!N0.hasOneUse())
+ DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
+ if (DoXform) {
+ LoadSDNode *LN0 = cast<LoadSDNode>(N0);
+ SDOperand ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, VT, LN0->getChain(),
+ LN0->getBasePtr(), LN0->getSrcValue(),
+ LN0->getSrcValueOffset(),
+ N0.getValueType(),
+ LN0->isVolatile(),
+ LN0->getAlignment());
+ CombineTo(N, ExtLoad);
+ SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
+ CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
+ // Extend SetCC uses if necessary.
+ for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
+ SDNode *SetCC = SetCCs[i];
+ SmallVector<SDOperand, 4> Ops;
+ for (unsigned j = 0; j != 2; ++j) {
+ SDOperand SOp = SetCC->getOperand(j);
+ if (SOp == Trunc)
+ Ops.push_back(ExtLoad);
+ else
+ Ops.push_back(DAG.getNode(ISD::SIGN_EXTEND, VT, SOp));
+ }
+ Ops.push_back(SetCC->getOperand(2));
+ CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
+ &Ops[0], Ops.size()));
+ }
+ return SDOperand(N, 0); // Return N so it doesn't get rechecked!
+ }
}
// fold (sext (sextload x)) -> (sext (truncate (sextload x)))
}
// fold (zext (load x)) -> (zext (truncate (zextload x)))
- if (ISD::isNON_EXTLoad(N0.Val) && N0.hasOneUse() &&
+ if (ISD::isNON_EXTLoad(N0.Val) &&
(!AfterLegalize||TLI.isLoadXLegal(ISD::ZEXTLOAD, N0.getValueType()))) {
- LoadSDNode *LN0 = cast<LoadSDNode>(N0);
- SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
- LN0->getBasePtr(), LN0->getSrcValue(),
- LN0->getSrcValueOffset(),
- N0.getValueType(),
- LN0->isVolatile(),
- LN0->getAlignment());
- CombineTo(N, ExtLoad);
- CombineTo(N0.Val, DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad),
- ExtLoad.getValue(1));
- return SDOperand(N, 0); // Return N so it doesn't get rechecked!
+ bool DoXform = true;
+ SmallVector<SDNode*, 4> SetCCs;
+ if (!N0.hasOneUse())
+ DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
+ if (DoXform) {
+ LoadSDNode *LN0 = cast<LoadSDNode>(N0);
+ SDOperand ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, VT, LN0->getChain(),
+ LN0->getBasePtr(), LN0->getSrcValue(),
+ LN0->getSrcValueOffset(),
+ N0.getValueType(),
+ LN0->isVolatile(),
+ LN0->getAlignment());
+ CombineTo(N, ExtLoad);
+ SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, N0.getValueType(), ExtLoad);
+ CombineTo(N0.Val, Trunc, ExtLoad.getValue(1));
+ // Extend SetCC uses if necessary.
+ for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
+ SDNode *SetCC = SetCCs[i];
+ SmallVector<SDOperand, 4> Ops;
+ for (unsigned j = 0; j != 2; ++j) {
+ SDOperand SOp = SetCC->getOperand(j);
+ if (SOp == Trunc)
+ Ops.push_back(ExtLoad);
+ else
+ Ops.push_back(DAG.getNode(ISD::ZERO_EXTEND, VT, SOp));
+ }
+ Ops.push_back(SetCC->getOperand(2));
+ CombineTo(SetCC, DAG.getNode(ISD::SETCC, SetCC->getValueType(0),
+ &Ops[0], Ops.size()));
+ }
+ return SDOperand(N, 0); // Return N so it doesn't get rechecked!
+ }
}
// fold (zext (zextload x)) -> (zext (truncate (zextload x)))
return SDOperand();
}
+/// GetDemandedBits - See if the specified operand can be simplified with the
+/// knowledge that only the bits specified by Mask are used. If so, return the
+/// simpler operand, otherwise return a null SDOperand.
+SDOperand DAGCombiner::GetDemandedBits(SDOperand V, uint64_t Mask) {
+ switch (V.getOpcode()) {
+ default: break;
+ case ISD::OR:
+ case ISD::XOR:
+ // If the LHS or RHS don't contribute bits to the or, drop them.
+ if (DAG.MaskedValueIsZero(V.getOperand(0), Mask))
+ return V.getOperand(1);
+ if (DAG.MaskedValueIsZero(V.getOperand(1), Mask))
+ return V.getOperand(0);
+ break;
+ case ISD::SRL:
+ // Only look at single-use SRLs.
+ if (!V.Val->hasOneUse())
+ break;
+ if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
+ // See if we can recursively simplify the LHS.
+ unsigned Amt = RHSC->getValue();
+ Mask = (Mask << Amt) & MVT::getIntVTBitMask(V.getValueType());
+ SDOperand SimplifyLHS = GetDemandedBits(V.getOperand(0), Mask);
+ if (SimplifyLHS.Val) {
+ return DAG.getNode(ISD::SRL, V.getValueType(),
+ SimplifyLHS, V.getOperand(1));
+ }
+ }
+ }
+ return SDOperand();
+}
+
/// ReduceLoadWidth - If the result of a wider load is shifted to right of N
/// bits and then truncated to a narrower type and where N is a multiple
/// of number of bits of the narrower type, transform it to a narrower load
MVT::ValueType PtrType = N0.getOperand(1).getValueType();
// For big endian targets, we need to adjust the offset to the pointer to
// load the correct bytes.
- if (!TLI.isLittleEndian())
- ShAmt = MVT::getSizeInBits(N0.getValueType()) - ShAmt - EVTBits;
+ if (!TLI.isLittleEndian()) {
+ unsigned LVTStoreBits = MVT::getStoreSizeInBits(N0.getValueType());
+ unsigned EVTStoreBits = MVT::getStoreSizeInBits(EVT);
+ ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
+ }
uint64_t PtrOff = ShAmt / 8;
+ unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
SDOperand NewPtr = DAG.getNode(ISD::ADD, PtrType, LN0->getBasePtr(),
DAG.getConstant(PtrOff, PtrType));
AddToWorkList(NewPtr.Val);
SDOperand Load = (ExtType == ISD::NON_EXTLOAD)
? DAG.getLoad(VT, LN0->getChain(), NewPtr,
LN0->getSrcValue(), LN0->getSrcValueOffset(),
- LN0->isVolatile(), LN0->getAlignment())
+ LN0->isVolatile(), NewAlign)
: DAG.getExtLoad(ExtType, VT, LN0->getChain(), NewPtr,
LN0->getSrcValue(), LN0->getSrcValueOffset(), EVT,
- LN0->isVolatile(), LN0->getAlignment());
+ LN0->isVolatile(), NewAlign);
AddToWorkList(N);
if (CombineSRL) {
- std::vector<SDNode*> NowDead;
- DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1), NowDead);
+ DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
CombineTo(N->getOperand(0).Val, Load);
} else
CombineTo(N0.Val, Load, Load.getValue(1));
return N0.getOperand(0);
}
+ // See if we can simplify the input to this truncate through knowledge that
+ // only the low bits are being used. For example "trunc (or (shl x, 8), y)"
+ // -> trunc y
+ SDOperand Shorter = GetDemandedBits(N0, MVT::getIntVTBitMask(VT));
+ if (Shorter.Val)
+ return DAG.getNode(ISD::TRUNCATE, VT, Shorter);
+
// fold (truncate (load x)) -> (smaller load x)
// fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
return ReduceLoadWidth(N);
}
// fold (fadd c1, c2) -> c1+c2
- if (N0CFP && N1CFP)
+ if (N0CFP && N1CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FADD, VT, N0, N1);
// canonicalize constant to RHS
if (N0CFP && !N1CFP)
}
// fold (fsub c1, c2) -> c1-c2
- if (N0CFP && N1CFP)
+ if (N0CFP && N1CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FSUB, VT, N0, N1);
// fold (0-B) -> -B
if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) {
}
// fold (fmul c1, c2) -> c1*c2
- if (N0CFP && N1CFP)
+ if (N0CFP && N1CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FMUL, VT, N0, N1);
// canonicalize constant to RHS
if (N0CFP && !N1CFP)
}
// fold (fdiv c1, c2) -> c1/c2
- if (N0CFP && N1CFP)
+ if (N0CFP && N1CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FDIV, VT, N0, N1);
MVT::ValueType VT = N->getValueType(0);
// fold (frem c1, c2) -> fmod(c1,c2)
- if (N0CFP && N1CFP)
+ if (N0CFP && N1CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FREM, VT, N0, N1);
return SDOperand();
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
MVT::ValueType VT = N->getValueType(0);
- if (N0CFP && N1CFP) // Constant fold
+ if (N0CFP && N1CFP && VT != MVT::ppcf128) // Constant fold
return DAG.getNode(ISD::FCOPYSIGN, VT, N0, N1);
if (N1CFP) {
MVT::ValueType VT = N->getValueType(0);
// fold (sint_to_fp c1) -> c1fp
- if (N0C)
+ if (N0C && N0.getValueType() != MVT::ppcf128)
return DAG.getNode(ISD::SINT_TO_FP, VT, N0);
return SDOperand();
}
MVT::ValueType VT = N->getValueType(0);
// fold (uint_to_fp c1) -> c1fp
- if (N0C)
+ if (N0C && N0.getValueType() != MVT::ppcf128)
return DAG.getNode(ISD::UINT_TO_FP, VT, N0);
return SDOperand();
}
MVT::ValueType VT = N->getValueType(0);
// fold (fp_to_uint c1fp) -> c1
- if (N0CFP)
+ if (N0CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FP_TO_UINT, VT, N0);
return SDOperand();
}
MVT::ValueType VT = N->getValueType(0);
// fold (fp_round c1fp) -> c1fp
- if (N0CFP)
+ if (N0CFP && N0.getValueType() != MVT::ppcf128)
return DAG.getNode(ISD::FP_ROUND, VT, N0);
// fold (fp_round (fp_extend x)) -> x
MVT::ValueType VT = N->getValueType(0);
// fold (fp_extend c1fp) -> c1fp
- if (N0CFP)
+ if (N0CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FP_EXTEND, VT, N0);
// fold (fpext (load x)) -> (fpext (fpround (extload x)))
MVT::ValueType VT = N->getValueType(0);
// fold (fabs c1) -> fabs(c1)
- if (N0CFP)
+ if (N0CFP && VT != MVT::ppcf128)
return DAG.getNode(ISD::FABS, VT, N0);
// fold (fabs (fabs x)) -> (fabs x)
if (N0.getOpcode() == ISD::FABS)
std::vector<SDNode*> NowDead;
if (isLoad) {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
- NowDead);
+ &NowDead);
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
- NowDead);
+ &NowDead);
} else {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
- NowDead);
+ &NowDead);
}
// Nodes can end up on the worklist more than once. Make sure we do
// Replace the uses of Ptr with uses of the updated base value.
DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0),
- NowDead);
+ &NowDead);
removeFromWorkList(Ptr.Val);
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
removeFromWorkList(NowDead[i]);
std::vector<SDNode*> NowDead;
if (isLoad) {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(0),
- NowDead);
+ &NowDead);
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 1), Result.getValue(2),
- NowDead);
+ &NowDead);
} else {
DAG.ReplaceAllUsesOfValueWith(SDOperand(N, 0), Result.getValue(1),
- NowDead);
+ &NowDead);
}
// Nodes can end up on the worklist more than once. Make sure we do
// Replace the uses of Use with uses of the updated base value.
DAG.ReplaceAllUsesOfValueWith(SDOperand(Op, 0),
Result.getValue(isLoad ? 1 : 0),
- NowDead);
+ &NowDead);
removeFromWorkList(Op);
for (unsigned i = 0, e = NowDead.size(); i != e; ++i)
removeFromWorkList(NowDead[i]);
// Replace the chain to void dependency.
if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
ReplLoad = DAG.getLoad(N->getValueType(0), BetterChain, Ptr,
- LD->getSrcValue(), LD->getSrcValueOffset(),
- LD->isVolatile(), LD->getAlignment());
+ LD->getSrcValue(), LD->getSrcValueOffset(),
+ LD->isVolatile(), LD->getAlignment());
} else {
ReplLoad = DAG.getExtLoad(LD->getExtensionType(),
LD->getValueType(0),
ST->getSrcValueOffset(), ST->isVolatile(),
ST->getAlignment());
} else if (TLI.isTypeLegal(MVT::i32)) {
- // Many FP stores are not make apparent until after legalize, e.g. for
+ // Many FP stores are not made apparent until after legalize, e.g. for
// argument passing. Since this is so common, custom legalize the
// 64-bit integer store into two 32-bit stores.
uint64_t Val = CFP->getValueAPF().convertToAPInt().getZExtValue();
Ptr = DAG.getNode(ISD::ADD, Ptr.getValueType(), Ptr,
DAG.getConstant(4, Ptr.getValueType()));
SVOffset += 4;
- if (Alignment > 4)
- Alignment = 4;
+ Alignment = MinAlign(Alignment, 4U);
SDOperand St1 = DAG.getStore(Chain, Hi, Ptr, ST->getSrcValue(),
SVOffset, isVolatile, Alignment);
return DAG.getNode(ISD::TokenFactor, MVT::Other, St0, St1);
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
return SDOperand(N, 0);
+ // FIXME: is there such a thing as a truncating indexed store?
+ if (ST->isTruncatingStore() && ST->getAddressingMode() == ISD::UNINDEXED &&
+ MVT::isInteger(Value.getValueType())) {
+ // See if we can simplify the input to this truncstore with knowledge that
+ // only the low bits are being used. For example:
+ // "truncstore (or (shl x, 8), y), i8" -> "truncstore y, i8"
+ SDOperand Shorter =
+ GetDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT()));
+ AddToWorkList(Value.Val);
+ if (Shorter.Val)
+ return DAG.getTruncStore(Chain, Shorter, Ptr, ST->getSrcValue(),
+ ST->getSrcValueOffset(), ST->getStoredVT(),
+ ST->isVolatile(), ST->getAlignment());
+
+ // Otherwise, see if we can simplify the operation with
+ // SimplifyDemandedBits, which only works if the value has a single use.
+ if (SimplifyDemandedBits(Value, MVT::getIntVTBitMask(ST->getStoredVT())))
+ return SDOperand(N, 0);
+ }
+
+ // If this is a load followed by a store to the same location, then the store
+ // is dead/noop.
+ if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
+ if (Chain.Val == Ld && Ld->getBasePtr() == Ptr &&
+ ST->getAddressingMode() == ISD::UNINDEXED &&
+ ST->getStoredVT() == Ld->getLoadedVT()) {
+ // The store is dead, remove it.
+ return Chain;
+ }
+ }
+
return SDOperand();
}
unsigned NumElts = MVT::getVectorNumElements(VT);
if (InVec.getOpcode() == ISD::BIT_CONVERT) {
MVT::ValueType BCVT = InVec.getOperand(0).getValueType();
- if (NumElts != MVT::getVectorNumElements(BCVT))
+ if (!MVT::isVector(BCVT) ||
+ NumElts != MVT::getVectorNumElements(BCVT))
return SDOperand();
InVec = InVec.getOperand(0);
EVT = MVT::getVectorElementType(BCVT);
projects / oota-llvm.git / blobdiff