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llvm-6502/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
Misha Brukman dedf2bd5a3 Convert tabs to spaces 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21439 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-22 04:01:18 +00:00

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//===-- SelectionDAG.cpp - Implement the SelectionDAG data structures -----===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements the SelectionDAG class.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Constants.h"
#include "llvm/GlobalValue.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/Target/TargetLowering.h"
#include <iostream>
#include <set>
#include <cmath>
#include <algorithm>
using namespace llvm;
static bool isCommutativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need commutative info for user ops!
}
}
static bool isAssociativeBinOp(unsigned Opcode) {
switch (Opcode) {
case ISD::ADD:
case ISD::MUL:
case ISD::AND:
case ISD::OR:
case ISD::XOR: return true;
default: return false; // FIXME: Need associative info for user ops!
}
}
static unsigned ExactLog2(uint64_t Val) {
unsigned Count = 0;
while (Val != 1) {
Val >>= 1;
++Count;
}
return Count;
}
// isInvertibleForFree - Return true if there is no cost to emitting the logical
// inverse of this node.
static bool isInvertibleForFree(SDOperand N) {
if (isa<ConstantSDNode>(N.Val)) return true;
if (isa<SetCCSDNode>(N.Val) && N.Val->hasOneUse())
return true;
return false;
}
/// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
/// when given the operation for (X op Y).
ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) {
// To perform this operation, we just need to swap the L and G bits of the
// operation.
unsigned OldL = (Operation >> 2) & 1;
unsigned OldG = (Operation >> 1) & 1;
return ISD::CondCode((Operation & ~6) | // Keep the N, U, E bits
(OldL << 1) | // New G bit
(OldG << 2)); // New L bit.
}
/// getSetCCInverse - Return the operation corresponding to !(X op Y), where
/// 'op' is a valid SetCC operation.
ISD::CondCode ISD::getSetCCInverse(ISD::CondCode Op, bool isInteger) {
unsigned Operation = Op;
if (isInteger)
Operation ^= 7; // Flip L, G, E bits, but not U.
else
Operation ^= 15; // Flip all of the condition bits.
if (Operation > ISD::SETTRUE2)
Operation &= ~8; // Don't let N and U bits get set.
return ISD::CondCode(Operation);
}
/// isSignedOp - For an integer comparison, return 1 if the comparison is a
/// signed operation and 2 if the result is an unsigned comparison. Return zero
/// if the operation does not depend on the sign of the input (setne and seteq).
static int isSignedOp(ISD::CondCode Opcode) {
switch (Opcode) {
default: assert(0 && "Illegal integer setcc operation!");
case ISD::SETEQ:
case ISD::SETNE: return 0;
case ISD::SETLT:
case ISD::SETLE:
case ISD::SETGT:
case ISD::SETGE: return 1;
case ISD::SETULT:
case ISD::SETULE:
case ISD::SETUGT:
case ISD::SETUGE: return 2;
}
}
/// getSetCCOrOperation - Return the result of a logical OR between different
/// comparisons of identical values: ((X op1 Y) | (X op2 Y)). This function
/// returns SETCC_INVALID if it is not possible to represent the resultant
/// comparison.
ISD::CondCode ISD::getSetCCOrOperation(ISD::CondCode Op1, ISD::CondCode Op2,
bool isInteger) {
if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3)
// Cannot fold a signed integer setcc with an unsigned integer setcc.
return ISD::SETCC_INVALID;
unsigned Op = Op1 | Op2; // Combine all of the condition bits.
// If the N and U bits get set then the resultant comparison DOES suddenly
// care about orderedness, and is true when ordered.
if (Op > ISD::SETTRUE2)
Op &= ~16; // Clear the N bit.
return ISD::CondCode(Op);
}
/// getSetCCAndOperation - Return the result of a logical AND between different
/// comparisons of identical values: ((X op1 Y) & (X op2 Y)). This
/// function returns zero if it is not possible to represent the resultant
/// comparison.
ISD::CondCode ISD::getSetCCAndOperation(ISD::CondCode Op1, ISD::CondCode Op2,
bool isInteger) {
if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3)
// Cannot fold a signed setcc with an unsigned setcc.
return ISD::SETCC_INVALID;
// Combine all of the condition bits.
return ISD::CondCode(Op1 & Op2);
}
const TargetMachine &SelectionDAG::getTarget() const {
return TLI.getTargetMachine();
}
/// RemoveDeadNodes - This method deletes all unreachable nodes in the
/// SelectionDAG, including nodes (like loads) that have uses of their token
/// chain but no other uses and no side effect. If a node is passed in as an
/// argument, it is used as the seed for node deletion.
void SelectionDAG::RemoveDeadNodes(SDNode *N) {
std::set<SDNode*> AllNodeSet(AllNodes.begin(), AllNodes.end());
// Create a dummy node (which is not added to allnodes), that adds a reference
// to the root node, preventing it from being deleted.
SDNode *DummyNode = new SDNode(ISD::EntryToken, getRoot());
DeleteNodeIfDead(N, &AllNodeSet);
Restart:
unsigned NumNodes = AllNodeSet.size();
for (std::set<SDNode*>::iterator I = AllNodeSet.begin(), E = AllNodeSet.end();
I != E; ++I) {
// Try to delete this node.
DeleteNodeIfDead(*I, &AllNodeSet);
// If we actually deleted any nodes, do not use invalid iterators in
// AllNodeSet.
if (AllNodeSet.size() != NumNodes)
goto Restart;
}
// Restore AllNodes.
if (AllNodes.size() != NumNodes)
AllNodes.assign(AllNodeSet.begin(), AllNodeSet.end());
// If the root changed (e.g. it was a dead load, update the root).
setRoot(DummyNode->getOperand(0));
// Now that we are done with the dummy node, delete it.
DummyNode->getOperand(0).Val->removeUser(DummyNode);
delete DummyNode;
}
void SelectionDAG::DeleteNodeIfDead(SDNode *N, void *NodeSet) {
if (!N->use_empty())
return;
// Okay, we really are going to delete this node. First take this out of the
// appropriate CSE map.
switch (N->getOpcode()) {
case ISD::Constant:
Constants.erase(std::make_pair(cast<ConstantSDNode>(N)->getValue(),
N->getValueType(0)));
break;
case ISD::ConstantFP: {
union {
double DV;
uint64_t IV;
};
DV = cast<ConstantFPSDNode>(N)->getValue();
ConstantFPs.erase(std::make_pair(IV, N->getValueType(0)));
break;
}
case ISD::GlobalAddress:
GlobalValues.erase(cast<GlobalAddressSDNode>(N)->getGlobal());
break;
case ISD::FrameIndex:
FrameIndices.erase(cast<FrameIndexSDNode>(N)->getIndex());
break;
case ISD::ConstantPool:
ConstantPoolIndices.erase(cast<ConstantPoolSDNode>(N)->getIndex());
break;
case ISD::BasicBlock:
BBNodes.erase(cast<BasicBlockSDNode>(N)->getBasicBlock());
break;
case ISD::ExternalSymbol:
ExternalSymbols.erase(cast<ExternalSymbolSDNode>(N)->getSymbol());
break;
case ISD::LOAD:
Loads.erase(std::make_pair(N->getOperand(1),
std::make_pair(N->getOperand(0),
N->getValueType(0))));
break;
case ISD::SETCC:
SetCCs.erase(std::make_pair(std::make_pair(N->getOperand(0),
N->getOperand(1)),
std::make_pair(
cast<SetCCSDNode>(N)->getCondition(),
N->getValueType(0))));
break;
case ISD::TRUNCSTORE:
case ISD::SIGN_EXTEND_INREG:
case ISD::FP_ROUND_INREG:
case ISD::EXTLOAD:
case ISD::SEXTLOAD:
case ISD::ZEXTLOAD: {
EVTStruct NN;
NN.Opcode = N->getOpcode();
NN.VT = N->getValueType(0);
NN.EVT = cast<MVTSDNode>(N)->getExtraValueType();
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
NN.Ops.push_back(N->getOperand(i));
MVTSDNodes.erase(NN);
break;
}
default:
if (N->getNumOperands() == 1)
UnaryOps.erase(std::make_pair(N->getOpcode(),
std::make_pair(N->getOperand(0),
N->getValueType(0))));
else if (N->getNumOperands() == 2)
BinaryOps.erase(std::make_pair(N->getOpcode(),
std::make_pair(N->getOperand(0),
N->getOperand(1))));
break;
}
// Next, brutally remove the operand list.
while (!N->Operands.empty()) {
SDNode *O = N->Operands.back().Val;
N->Operands.pop_back();
O->removeUser(N);
// Now that we removed this operand, see if there are no uses of it left.
DeleteNodeIfDead(O, NodeSet);
}
// Remove the node from the nodes set and delete it.
std::set<SDNode*> &AllNodeSet = *(std::set<SDNode*>*)NodeSet;
AllNodeSet.erase(N);
// Now that the node is gone, check to see if any of the operands of this node
// are dead now.
delete N;
}
SelectionDAG::~SelectionDAG() {
for (unsigned i = 0, e = AllNodes.size(); i != e; ++i)
delete AllNodes[i];
}
SDOperand SelectionDAG::getZeroExtendInReg(SDOperand Op, MVT::ValueType VT) {
if (Op.getValueType() == VT) return Op;
int64_t Imm = ~0ULL >> 64-MVT::getSizeInBits(VT);
return getNode(ISD::AND, Op.getValueType(), Op,
getConstant(Imm, Op.getValueType()));
}
SDOperand SelectionDAG::getConstant(uint64_t Val, MVT::ValueType VT) {
assert(MVT::isInteger(VT) && "Cannot create FP integer constant!");
// Mask out any bits that are not valid for this constant.
if (VT != MVT::i64)
Val &= ((uint64_t)1 << MVT::getSizeInBits(VT)) - 1;
SDNode *&N = Constants[std::make_pair(Val, VT)];
if (N) return SDOperand(N, 0);
N = new ConstantSDNode(Val, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getConstantFP(double Val, MVT::ValueType VT) {
assert(MVT::isFloatingPoint(VT) && "Cannot create integer FP constant!");
if (VT == MVT::f32)
Val = (float)Val; // Mask out extra precision.
// Do the map lookup using the actual bit pattern for the floating point
// value, so that we don't have problems with 0.0 comparing equal to -0.0, and
// we don't have issues with SNANs.
union {
double DV;
uint64_t IV;
};
DV = Val;
SDNode *&N = ConstantFPs[std::make_pair(IV, VT)];
if (N) return SDOperand(N, 0);
N = new ConstantFPSDNode(Val, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getGlobalAddress(const GlobalValue *GV,
MVT::ValueType VT) {
SDNode *&N = GlobalValues[GV];
if (N) return SDOperand(N, 0);
N = new GlobalAddressSDNode(GV,VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getFrameIndex(int FI, MVT::ValueType VT) {
SDNode *&N = FrameIndices[FI];
if (N) return SDOperand(N, 0);
N = new FrameIndexSDNode(FI, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getConstantPool(unsigned CPIdx, MVT::ValueType VT) {
SDNode *N = ConstantPoolIndices[CPIdx];
if (N) return SDOperand(N, 0);
N = new ConstantPoolSDNode(CPIdx, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getBasicBlock(MachineBasicBlock *MBB) {
SDNode *&N = BBNodes[MBB];
if (N) return SDOperand(N, 0);
N = new BasicBlockSDNode(MBB);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getExternalSymbol(const char *Sym, MVT::ValueType VT) {
SDNode *&N = ExternalSymbols[Sym];
if (N) return SDOperand(N, 0);
N = new ExternalSymbolSDNode(Sym, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getSetCC(ISD::CondCode Cond, MVT::ValueType VT,
SDOperand N1, SDOperand N2) {
// These setcc operations always fold.
switch (Cond) {
default: break;
case ISD::SETFALSE:
case ISD::SETFALSE2: return getConstant(0, VT);
case ISD::SETTRUE:
case ISD::SETTRUE2: return getConstant(1, VT);
}
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val)) {
uint64_t C2 = N2C->getValue();
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
uint64_t C1 = N1C->getValue();
// Sign extend the operands if required
if (ISD::isSignedIntSetCC(Cond)) {
C1 = N1C->getSignExtended();
C2 = N2C->getSignExtended();
}
switch (Cond) {
default: assert(0 && "Unknown integer setcc!");
case ISD::SETEQ: return getConstant(C1 == C2, VT);
case ISD::SETNE: return getConstant(C1 != C2, VT);
case ISD::SETULT: return getConstant(C1 < C2, VT);
case ISD::SETUGT: return getConstant(C1 > C2, VT);
case ISD::SETULE: return getConstant(C1 <= C2, VT);
case ISD::SETUGE: return getConstant(C1 >= C2, VT);
case ISD::SETLT: return getConstant((int64_t)C1 < (int64_t)C2, VT);
case ISD::SETGT: return getConstant((int64_t)C1 > (int64_t)C2, VT);
case ISD::SETLE: return getConstant((int64_t)C1 <= (int64_t)C2, VT);
case ISD::SETGE: return getConstant((int64_t)C1 >= (int64_t)C2, VT);
}
} else {
// If the LHS is a ZERO_EXTEND and if this is an ==/!= comparison, perform
// the comparison on the input.
if (N1.getOpcode() == ISD::ZERO_EXTEND) {
unsigned InSize = MVT::getSizeInBits(N1.getOperand(0).getValueType());
// If the comparison constant has bits in the upper part, the
// zero-extended value could never match.
if (C2 & (~0ULL << InSize)) {
unsigned VSize = MVT::getSizeInBits(N1.getValueType());
switch (Cond) {
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETEQ: return getConstant(0, VT);
case ISD::SETULT:
case ISD::SETULE:
case ISD::SETNE: return getConstant(1, VT);
case ISD::SETGT:
case ISD::SETGE:
// True if the sign bit of C2 is set.
return getConstant((C2 & (1ULL << VSize)) != 0, VT);
case ISD::SETLT:
case ISD::SETLE:
// True if the sign bit of C2 isn't set.
return getConstant((C2 & (1ULL << VSize)) == 0, VT);
default:
break;
}
}
// Otherwise, we can perform the comparison with the low bits.
switch (Cond) {
case ISD::SETEQ:
case ISD::SETNE:
case ISD::SETUGT:
case ISD::SETUGE:
case ISD::SETULT:
case ISD::SETULE:
return getSetCC(Cond, VT, N1.getOperand(0),
getConstant(C2, N1.getOperand(0).getValueType()));
default:
break; // todo, be more careful with signed comparisons
}
}
uint64_t MinVal, MaxVal;
unsigned OperandBitSize = MVT::getSizeInBits(N2C->getValueType(0));
if (ISD::isSignedIntSetCC(Cond)) {
MinVal = 1ULL << (OperandBitSize-1);
if (OperandBitSize != 1) // Avoid X >> 64, which is undefined.
MaxVal = ~0ULL >> (65-OperandBitSize);
else
MaxVal = 0;
} else {
MinVal = 0;
MaxVal = ~0ULL >> (64-OperandBitSize);
}
// Canonicalize GE/LE comparisons to use GT/LT comparisons.
if (Cond == ISD::SETGE || Cond == ISD::SETUGE) {
if (C2 == MinVal) return getConstant(1, VT); // X >= MIN --> true
--C2; // X >= C1 --> X > (C1-1)
Cond = (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT;
N2 = getConstant(C2, N2.getValueType());
N2C = cast<ConstantSDNode>(N2.Val);
}
if (Cond == ISD::SETLE || Cond == ISD::SETULE) {
if (C2 == MaxVal) return getConstant(1, VT); // X <= MAX --> true
++C2; // X <= C1 --> X < (C1+1)
Cond = (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT;
N2 = getConstant(C2, N2.getValueType());
N2C = cast<ConstantSDNode>(N2.Val);
}
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal)
return getConstant(0, VT); // X < MIN --> false
// Canonicalize setgt X, Min --> setne X, Min
if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MinVal)
return getSetCC(ISD::SETNE, VT, N1, N2);
// If we have setult X, 1, turn it into seteq X, 0
if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal+1)
return getSetCC(ISD::SETEQ, VT, N1,
getConstant(MinVal, N1.getValueType()));
// If we have setugt X, Max-1, turn it into seteq X, Max
else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MaxVal-1)
return getSetCC(ISD::SETEQ, VT, N1,
getConstant(MaxVal, N1.getValueType()));
// If we have "setcc X, C1", check to see if we can shrink the immediate
// by changing cc.
// SETUGT X, SINTMAX -> SETLT X, 0
if (Cond == ISD::SETUGT && OperandBitSize != 1 &&
C2 == (~0ULL >> (65-OperandBitSize)))
return getSetCC(ISD::SETLT, VT, N1, getConstant(0, N2.getValueType()));
// FIXME: Implement the rest of these.
// Fold bit comparisons when we can.
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
VT == N1.getValueType() && N1.getOpcode() == ISD::AND)
if (ConstantSDNode *AndRHS =
dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
if (Cond == ISD::SETNE && C2 == 0) {// (X & 8) != 0 --> (X & 8) >> 3
// Perform the xform if the AND RHS is a single bit.
if ((AndRHS->getValue() & (AndRHS->getValue()-1)) == 0) {
return getNode(ISD::SRL, VT, N1,
getConstant(ExactLog2(AndRHS->getValue()),
TLI.getShiftAmountTy()));
}
} else if (Cond == ISD::SETEQ && C2 == AndRHS->getValue()) {
// (X & 8) == 8 --> (X & 8) >> 3
// Perform the xform if C2 is a single bit.
if ((C2 & (C2-1)) == 0) {
return getNode(ISD::SRL, VT, N1,
getConstant(ExactLog2(C2),TLI.getShiftAmountTy()));
}
}
}
}
} else if (isa<ConstantSDNode>(N1.Val)) {
// Ensure that the constant occurs on the RHS.
return getSetCC(ISD::getSetCCSwappedOperands(Cond), VT, N2, N1);
}
if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1.Val))
if (ConstantFPSDNode *N2C = dyn_cast<ConstantFPSDNode>(N2.Val)) {
double C1 = N1C->getValue(), C2 = N2C->getValue();
switch (Cond) {
default: break; // FIXME: Implement the rest of these!
case ISD::SETEQ: return getConstant(C1 == C2, VT);
case ISD::SETNE: return getConstant(C1 != C2, VT);
case ISD::SETLT: return getConstant(C1 < C2, VT);
case ISD::SETGT: return getConstant(C1 > C2, VT);
case ISD::SETLE: return getConstant(C1 <= C2, VT);
case ISD::SETGE: return getConstant(C1 >= C2, VT);
}
} else {
// Ensure that the constant occurs on the RHS.
Cond = ISD::getSetCCSwappedOperands(Cond);
std::swap(N1, N2);
}
if (N1 == N2) {
// We can always fold X == Y for integer setcc's.
if (MVT::isInteger(N1.getValueType()))
return getConstant(ISD::isTrueWhenEqual(Cond), VT);
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return getConstant(ISD::isTrueWhenEqual(Cond), VT);
if (UOF == ISD::isTrueWhenEqual(Cond))
return getConstant(UOF, VT);
// Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO
// if it is not already.
Cond = UOF == 0 ? ISD::SETUO : ISD::SETO;
}
if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) &&
MVT::isInteger(N1.getValueType())) {
if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB ||
N1.getOpcode() == ISD::XOR) {
// Simplify (X+Y) == (X+Z) --> Y == Z
if (N1.getOpcode() == N2.getOpcode()) {
if (N1.getOperand(0) == N2.getOperand(0))
return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(1));
if (N1.getOperand(1) == N2.getOperand(1))
return getSetCC(Cond, VT, N1.getOperand(0), N2.getOperand(0));
if (isCommutativeBinOp(N1.getOpcode())) {
// If X op Y == Y op X, try other combinations.
if (N1.getOperand(0) == N2.getOperand(1))
return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(0));
if (N1.getOperand(1) == N2.getOperand(0))
return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(1));
}
}
// FIXME: move this stuff to the DAG Combiner when it exists!
// Simplify (X+Z) == X --> Z == 0
if (N1.getOperand(0) == N2)
return getSetCC(Cond, VT, N1.getOperand(1),
getConstant(0, N1.getValueType()));
if (N1.getOperand(1) == N2) {
if (isCommutativeBinOp(N1.getOpcode()))
return getSetCC(Cond, VT, N1.getOperand(0),
getConstant(0, N1.getValueType()));
else {
assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
// (Z-X) == X --> Z == X<<1
return getSetCC(Cond, VT, N1.getOperand(0),
getNode(ISD::SHL, N2.getValueType(),
N2, getConstant(1, TLI.getShiftAmountTy())));
}
}
}
if (N2.getOpcode() == ISD::ADD || N2.getOpcode() == ISD::SUB ||
N2.getOpcode() == ISD::XOR) {
// Simplify X == (X+Z) --> Z == 0
if (N2.getOperand(0) == N1)
return getSetCC(Cond, VT, N2.getOperand(1),
getConstant(0, N2.getValueType()));
else if (N2.getOperand(1) == N1)
return getSetCC(Cond, VT, N2.getOperand(0),
getConstant(0, N2.getValueType()));
}
}
// Fold away ALL boolean setcc's.
if (N1.getValueType() == MVT::i1) {
switch (Cond) {
default: assert(0 && "Unknown integer setcc!");
case ISD::SETEQ: // X == Y -> (X^Y)^1
N1 = getNode(ISD::XOR, MVT::i1,
getNode(ISD::XOR, MVT::i1, N1, N2),
getConstant(1, MVT::i1));
break;
case ISD::SETNE: // X != Y --> (X^Y)
N1 = getNode(ISD::XOR, MVT::i1, N1, N2);
break;
case ISD::SETGT: // X >s Y --> X == 0 & Y == 1 --> X^1 & Y
case ISD::SETULT: // X <u Y --> X == 0 & Y == 1 --> X^1 & Y
N1 = getNode(ISD::AND, MVT::i1, N2,
getNode(ISD::XOR, MVT::i1, N1, getConstant(1, MVT::i1)));
break;
case ISD::SETLT: // X <s Y --> X == 1 & Y == 0 --> Y^1 & X
case ISD::SETUGT: // X >u Y --> X == 1 & Y == 0 --> Y^1 & X
N1 = getNode(ISD::AND, MVT::i1, N1,
getNode(ISD::XOR, MVT::i1, N2, getConstant(1, MVT::i1)));
break;
case ISD::SETULE: // X <=u Y --> X == 0 | Y == 1 --> X^1 | Y
case ISD::SETGE: // X >=s Y --> X == 0 | Y == 1 --> X^1 | Y
N1 = getNode(ISD::OR, MVT::i1, N2,
getNode(ISD::XOR, MVT::i1, N1, getConstant(1, MVT::i1)));
break;
case ISD::SETUGE: // X >=u Y --> X == 1 | Y == 0 --> Y^1 | X
case ISD::SETLE: // X <=s Y --> X == 1 | Y == 0 --> Y^1 | X
N1 = getNode(ISD::OR, MVT::i1, N1,
getNode(ISD::XOR, MVT::i1, N2, getConstant(1, MVT::i1)));
break;
}
if (VT != MVT::i1)
N1 = getNode(ISD::ZERO_EXTEND, VT, N1);
return N1;
}
SetCCSDNode *&N = SetCCs[std::make_pair(std::make_pair(N1, N2),
std::make_pair(Cond, VT))];
if (N) return SDOperand(N, 0);
N = new SetCCSDNode(Cond, N1, N2);
N->setValueTypes(VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
/// getNode - Gets or creates the specified node.
///
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) {
SDNode *N = new SDNode(Opcode, VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Operand) {
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Operand.Val)) {
uint64_t Val = C->getValue();
switch (Opcode) {
default: break;
case ISD::SIGN_EXTEND: return getConstant(C->getSignExtended(), VT);
case ISD::ZERO_EXTEND: return getConstant(Val, VT);
case ISD::TRUNCATE: return getConstant(Val, VT);
case ISD::SINT_TO_FP: return getConstantFP(C->getSignExtended(), VT);
case ISD::UINT_TO_FP: return getConstantFP(C->getValue(), VT);
}
}
if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Operand.Val))
switch (Opcode) {
case ISD::FNEG:
return getConstantFP(-C->getValue(), VT);
case ISD::FP_ROUND:
case ISD::FP_EXTEND:
return getConstantFP(C->getValue(), VT);
case ISD::FP_TO_SINT:
return getConstant((int64_t)C->getValue(), VT);
case ISD::FP_TO_UINT:
return getConstant((uint64_t)C->getValue(), VT);
}
unsigned OpOpcode = Operand.Val->getOpcode();
switch (Opcode) {
case ISD::TokenFactor:
return Operand; // Factor of one node? No factor.
case ISD::SIGN_EXTEND:
if (Operand.getValueType() == VT) return Operand; // noop extension
if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND)
return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
break;
case ISD::ZERO_EXTEND:
if (Operand.getValueType() == VT) return Operand; // noop extension
if (OpOpcode == ISD::ZERO_EXTEND) // (zext (zext x)) -> (zext x)
return getNode(ISD::ZERO_EXTEND, VT, Operand.Val->getOperand(0));
break;
case ISD::TRUNCATE:
if (Operand.getValueType() == VT) return Operand; // noop truncate
if (OpOpcode == ISD::TRUNCATE)
return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
else if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND) {
// If the source is smaller than the dest, we still need an extend.
if (Operand.Val->getOperand(0).getValueType() < VT)
return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
else if (Operand.Val->getOperand(0).getValueType() > VT)
return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0));
else
return Operand.Val->getOperand(0);
}
break;
case ISD::FNEG:
if (OpOpcode == ISD::SUB) // -(X-Y) -> (Y-X)
return getNode(ISD::SUB, VT, Operand.Val->getOperand(1),
Operand.Val->getOperand(0));
if (OpOpcode == ISD::FNEG) // --X -> X
return Operand.Val->getOperand(0);
break;
case ISD::FABS:
if (OpOpcode == ISD::FNEG) // abs(-X) -> abs(X)
return getNode(ISD::FABS, VT, Operand.Val->getOperand(0));
break;
}
SDNode *&N = UnaryOps[std::make_pair(Opcode, std::make_pair(Operand, VT))];
if (N) return SDOperand(N, 0);
N = new SDNode(Opcode, Operand);
N->setValueTypes(VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
/// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero. We use
/// this predicate to simplify operations downstream. V and Mask are known to
/// be the same type.
static bool MaskedValueIsZero(const SDOperand &Op, uint64_t Mask,
const TargetLowering &TLI) {
unsigned SrcBits;
if (Mask == 0) return true;
// If we know the result of a setcc has the top bits zero, use this info.
switch (Op.getOpcode()) {
case ISD::UNDEF:
return true;
case ISD::Constant:
return (cast<ConstantSDNode>(Op)->getValue() & Mask) == 0;
case ISD::SETCC:
return ((Mask & 1) == 0) &&
TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult;
case ISD::ZEXTLOAD:
SrcBits = MVT::getSizeInBits(cast<MVTSDNode>(Op)->getExtraValueType());
return (Mask & ((1ULL << SrcBits)-1)) == 0; // Returning only the zext bits.
case ISD::ZERO_EXTEND:
SrcBits = MVT::getSizeInBits(Op.getOperand(0).getValueType());
return MaskedValueIsZero(Op.getOperand(0),Mask & ((1ULL << SrcBits)-1),TLI);
case ISD::AND:
// (X & C1) & C2 == 0 iff C1 & C2 == 0.
if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
return MaskedValueIsZero(Op.getOperand(0),AndRHS->getValue() & Mask, TLI);
// FALL THROUGH
case ISD::OR:
case ISD::XOR:
return MaskedValueIsZero(Op.getOperand(0), Mask, TLI) &&
MaskedValueIsZero(Op.getOperand(1), Mask, TLI);
case ISD::SELECT:
return MaskedValueIsZero(Op.getOperand(1), Mask, TLI) &&
MaskedValueIsZero(Op.getOperand(2), Mask, TLI);
case ISD::SRL:
// (ushr X, C1) & C2 == 0 iff X & (C2 << C1) == 0
if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
uint64_t NewVal = Mask << ShAmt->getValue();
SrcBits = MVT::getSizeInBits(Op.getValueType());
if (SrcBits != 64) NewVal &= (1ULL << SrcBits)-1;
return MaskedValueIsZero(Op.getOperand(0), NewVal, TLI);
}
return false;
case ISD::SHL:
// (ushl X, C1) & C2 == 0 iff X & (C2 >> C1) == 0
if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
uint64_t NewVal = Mask >> ShAmt->getValue();
return MaskedValueIsZero(Op.getOperand(0), NewVal, TLI);
}
return false;
default: break;
}
return false;
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2) {
#ifndef NDEBUG
switch (Opcode) {
case ISD::TokenFactor:
assert(VT == MVT::Other && N1.getValueType() == MVT::Other &&
N2.getValueType() == MVT::Other && "Invalid token factor!");
break;
case ISD::AND:
case ISD::OR:
case ISD::XOR:
case ISD::UDIV:
case ISD::UREM:
assert(MVT::isInteger(VT) && "This operator does not apply to FP types!");
// fall through
case ISD::ADD:
case ISD::SUB:
case ISD::MUL:
case ISD::SDIV:
case ISD::SREM:
assert(N1.getValueType() == N2.getValueType() &&
N1.getValueType() == VT && "Binary operator types must match!");
break;
case ISD::SHL:
case ISD::SRA:
case ISD::SRL:
assert(VT == N1.getValueType() &&
"Shift operators return type must be the same as their first arg");
assert(MVT::isInteger(VT) && MVT::isInteger(N2.getValueType()) &&
VT != MVT::i1 && "Shifts only work on integers");
break;
default: break;
}
#endif
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
if (N1C) {
if (N2C) {
uint64_t C1 = N1C->getValue(), C2 = N2C->getValue();
switch (Opcode) {
case ISD::ADD: return getConstant(C1 + C2, VT);
case ISD::SUB: return getConstant(C1 - C2, VT);
case ISD::MUL: return getConstant(C1 * C2, VT);
case ISD::UDIV:
if (C2) return getConstant(C1 / C2, VT);
break;
case ISD::UREM :
if (C2) return getConstant(C1 % C2, VT);
break;
case ISD::SDIV :
if (C2) return getConstant(N1C->getSignExtended() /
N2C->getSignExtended(), VT);
break;
case ISD::SREM :
if (C2) return getConstant(N1C->getSignExtended() %
N2C->getSignExtended(), VT);
break;
case ISD::AND : return getConstant(C1 & C2, VT);
case ISD::OR : return getConstant(C1 | C2, VT);
case ISD::XOR : return getConstant(C1 ^ C2, VT);
case ISD::SHL : return getConstant(C1 << (int)C2, VT);
case ISD::SRL : return getConstant(C1 >> (unsigned)C2, VT);
case ISD::SRA : return getConstant(N1C->getSignExtended() >>(int)C2, VT);
default: break;
}
} else { // Cannonicalize constant to RHS if commutative
if (isCommutativeBinOp(Opcode)) {
std::swap(N1C, N2C);
std::swap(N1, N2);
}
}
switch (Opcode) {
default: break;
case ISD::SHL: // shl 0, X -> 0
if (N1C->isNullValue()) return N1;
break;
case ISD::SRL: // srl 0, X -> 0
if (N1C->isNullValue()) return N1;
break;
case ISD::SRA: // sra -1, X -> -1
if (N1C->isAllOnesValue()) return N1;
break;
}
}
if (N2C) {
uint64_t C2 = N2C->getValue();
switch (Opcode) {
case ISD::ADD:
if (!C2) return N1; // add X, 0 -> X
break;
case ISD::SUB:
if (!C2) return N1; // sub X, 0 -> X
break;
case ISD::MUL:
if (!C2) return N2; // mul X, 0 -> 0
if (N2C->isAllOnesValue()) // mul X, -1 -> 0-X
return getNode(ISD::SUB, VT, getConstant(0, VT), N1);
// FIXME: Move this to the DAG combiner when it exists.
if ((C2 & C2-1) == 0) {
SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy());
return getNode(ISD::SHL, VT, N1, ShAmt);
}
break;
case ISD::UDIV:
// FIXME: Move this to the DAG combiner when it exists.
if ((C2 & C2-1) == 0 && C2) {
SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy());
return getNode(ISD::SRL, VT, N1, ShAmt);
}
break;
case ISD::SHL:
case ISD::SRL:
case ISD::SRA:
// If the shift amount is bigger than the size of the data, then all the
// bits are shifted out. Simplify to undef.
if (C2 >= MVT::getSizeInBits(N1.getValueType())) {
return getNode(ISD::UNDEF, N1.getValueType());
}
if (C2 == 0) return N1;
break;
case ISD::AND:
if (!C2) return N2; // X and 0 -> 0
if (N2C->isAllOnesValue())
return N1; // X and -1 -> X
if (MaskedValueIsZero(N1, C2, TLI)) // X and 0 -> 0
return getConstant(0, VT);
{
uint64_t NotC2 = ~C2;
if (VT != MVT::i64)
NotC2 &= (1ULL << MVT::getSizeInBits(VT))-1;
if (MaskedValueIsZero(N1, NotC2, TLI))
return N1; // if (X & ~C2) -> 0, the and is redundant
}
// FIXME: Should add a corresponding version of this for
// ZERO_EXTEND/SIGN_EXTEND by converting them to an ANY_EXTEND node which
// we don't have yet.
// and (sign_extend_inreg x:16:32), 1 -> and x, 1
if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
// If we are masking out the part of our input that was extended, just
// mask the input to the extension directly.
unsigned ExtendBits =
MVT::getSizeInBits(cast<MVTSDNode>(N1)->getExtraValueType());
if ((C2 & (~0ULL << ExtendBits)) == 0)
return getNode(ISD::AND, VT, N1.getOperand(0), N2);
}
break;
case ISD::OR:
if (!C2)return N1; // X or 0 -> X
if (N2C->isAllOnesValue())
return N2; // X or -1 -> -1
break;
case ISD::XOR:
if (!C2) return N1; // X xor 0 -> X
if (N2C->isAllOnesValue()) {
if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(N1.Val)){
// !(X op Y) -> (X !op Y)
bool isInteger = MVT::isInteger(SetCC->getOperand(0).getValueType());
return getSetCC(ISD::getSetCCInverse(SetCC->getCondition(),isInteger),
SetCC->getValueType(0),
SetCC->getOperand(0), SetCC->getOperand(1));
} else if (N1.getOpcode() == ISD::AND || N1.getOpcode() == ISD::OR) {
SDNode *Op = N1.Val;
// !(X or Y) -> (!X and !Y) iff X or Y are freely invertible
// !(X and Y) -> (!X or !Y) iff X or Y are freely invertible
SDOperand LHS = Op->getOperand(0), RHS = Op->getOperand(1);
if (isInvertibleForFree(RHS) || isInvertibleForFree(LHS)) {
LHS = getNode(ISD::XOR, VT, LHS, N2); // RHS = ~LHS
RHS = getNode(ISD::XOR, VT, RHS, N2); // RHS = ~RHS
if (Op->getOpcode() == ISD::AND)
return getNode(ISD::OR, VT, LHS, RHS);
return getNode(ISD::AND, VT, LHS, RHS);
}
}
// X xor -1 -> not(x) ?
}
break;
}
// Reassociate ((X op C1) op C2) if possible.
if (N1.getOpcode() == Opcode && isAssociativeBinOp(Opcode))
if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N1.Val->getOperand(1)))
return getNode(Opcode, VT, N1.Val->getOperand(0),
getNode(Opcode, VT, N2, N1.Val->getOperand(1)));
}
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1.Val);
ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2.Val);
if (N1CFP)
if (N2CFP) {
double C1 = N1CFP->getValue(), C2 = N2CFP->getValue();
switch (Opcode) {
case ISD::ADD: return getConstantFP(C1 + C2, VT);
case ISD::SUB: return getConstantFP(C1 - C2, VT);
case ISD::MUL: return getConstantFP(C1 * C2, VT);
case ISD::SDIV:
if (C2) return getConstantFP(C1 / C2, VT);
break;
case ISD::SREM :
if (C2) return getConstantFP(fmod(C1, C2), VT);
break;
default: break;
}
} else { // Cannonicalize constant to RHS if commutative
if (isCommutativeBinOp(Opcode)) {
std::swap(N1CFP, N2CFP);
std::swap(N1, N2);
}
}
// Finally, fold operations that do not require constants.
switch (Opcode) {
case ISD::TokenFactor:
if (N1.getOpcode() == ISD::EntryToken)
return N2;
if (N2.getOpcode() == ISD::EntryToken)
return N1;
break;
case ISD::AND:
case ISD::OR:
if (SetCCSDNode *LHS = dyn_cast<SetCCSDNode>(N1.Val))
if (SetCCSDNode *RHS = dyn_cast<SetCCSDNode>(N2.Val)) {
SDOperand LL = LHS->getOperand(0), RL = RHS->getOperand(0);
SDOperand LR = LHS->getOperand(1), RR = RHS->getOperand(1);
ISD::CondCode Op2 = RHS->getCondition();
// (X != 0) | (Y != 0) -> (X|Y != 0)
// (X == 0) & (Y == 0) -> (X|Y == 0)
if (LR == RR && isa<ConstantSDNode>(LR) &&
cast<ConstantSDNode>(LR)->getValue() == 0 &&
Op2 == LHS->getCondition() && MVT::isInteger(LL.getValueType())) {
if ((Op2 == ISD::SETEQ && Opcode == ISD::AND) ||
(Op2 == ISD::SETNE && Opcode == ISD::OR))
return getSetCC(Op2, VT,
getNode(ISD::OR, LR.getValueType(), LL, RL), LR);
}
// (X op1 Y) | (Y op2 X) -> (X op1 Y) | (X swapop2 Y)
if (LL == RR && LR == RL) {
Op2 = ISD::getSetCCSwappedOperands(Op2);
goto MatchedBackwards;
}
if (LL == RL && LR == RR) {
MatchedBackwards:
ISD::CondCode Result;
bool isInteger = MVT::isInteger(LL.getValueType());
if (Opcode == ISD::OR)
Result = ISD::getSetCCOrOperation(LHS->getCondition(), Op2,
isInteger);
else
Result = ISD::getSetCCAndOperation(LHS->getCondition(), Op2,
isInteger);
if (Result != ISD::SETCC_INVALID)
return getSetCC(Result, LHS->getValueType(0), LL, LR);
}
}
// and/or zext(a), zext(b) -> zext(and/or a, b)
if (N1.getOpcode() == ISD::ZERO_EXTEND &&
N2.getOpcode() == ISD::ZERO_EXTEND &&
N1.getOperand(0).getValueType() == N2.getOperand(0).getValueType())
return getNode(ISD::ZERO_EXTEND, VT,
getNode(Opcode, N1.getOperand(0).getValueType(),
N1.getOperand(0), N2.getOperand(0)));
break;
case ISD::XOR:
if (N1 == N2) return getConstant(0, VT); // xor X, Y -> 0
break;
case ISD::ADD:
if (N2.getOpcode() == ISD::FNEG) // (A+ (-B) -> A-B
return getNode(ISD::SUB, VT, N1, N2.getOperand(0));
if (N1.getOpcode() == ISD::FNEG) // ((-A)+B) -> B-A
return getNode(ISD::SUB, VT, N2, N1.getOperand(0));
if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) &&
cast<ConstantSDNode>(N1.getOperand(0))->getValue() == 0)
return getNode(ISD::SUB, VT, N2, N1.getOperand(1)); // (0-A)+B -> B-A
if (N2.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N2.getOperand(0)) &&
cast<ConstantSDNode>(N2.getOperand(0))->getValue() == 0)
return getNode(ISD::SUB, VT, N1, N2.getOperand(1)); // A+(0-B) -> A-B
break;
case ISD::SUB:
if (N1.getOpcode() == ISD::ADD) {
if (N1.Val->getOperand(0) == N2)
return N1.Val->getOperand(1); // (A+B)-A == B
if (N1.Val->getOperand(1) == N2)
return N1.Val->getOperand(0); // (A+B)-B == A
}
if (N2.getOpcode() == ISD::FNEG) // (A- (-B) -> A+B
return getNode(ISD::ADD, VT, N1, N2.getOperand(0));
break;
// FIXME: figure out how to safely handle things like
// int foo(int x) { return 1 << (x & 255); }
// int bar() { return foo(256); }
#if 0
case ISD::SHL:
case ISD::SRL:
case ISD::SRA:
if (N2.getOpcode() == ISD::SIGN_EXTEND_INREG &&
cast<MVTSDNode>(N2)->getExtraValueType() != MVT::i1)
return getNode(Opcode, VT, N1, N2.getOperand(0));
else if (N2.getOpcode() == ISD::AND)
if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N2.getOperand(1))) {
// If the and is only masking out bits that cannot effect the shift,
// eliminate the and.
unsigned NumBits = MVT::getSizeInBits(VT);
if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
return getNode(Opcode, VT, N1, N2.getOperand(0));
}
break;
#endif
}
SDNode *&N = BinaryOps[std::make_pair(Opcode, std::make_pair(N1, N2))];
if (N) return SDOperand(N, 0);
N = new SDNode(Opcode, N1, N2);
N->setValueTypes(VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getLoad(MVT::ValueType VT,
SDOperand Chain, SDOperand Ptr) {
SDNode *&N = Loads[std::make_pair(Ptr, std::make_pair(Chain, VT))];
if (N) return SDOperand(N, 0);
N = new SDNode(ISD::LOAD, Chain, Ptr);
// Loads have a token chain.
N->setValueTypes(VT, MVT::Other);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3) {
// Perform various simplifications.
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val);
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val);
ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val);
switch (Opcode) {
case ISD::SELECT:
if (N1C)
if (N1C->getValue())
return N2; // select true, X, Y -> X
else
return N3; // select false, X, Y -> Y
if (N2 == N3) return N2; // select C, X, X -> X
if (VT == MVT::i1) { // Boolean SELECT
if (N2C) {
if (N2C->getValue()) // select C, 1, X -> C | X
return getNode(ISD::OR, VT, N1, N3);
else // select C, 0, X -> ~C & X
return getNode(ISD::AND, VT,
getNode(ISD::XOR, N1.getValueType(), N1,
getConstant(1, N1.getValueType())), N3);
} else if (N3C) {
if (N3C->getValue()) // select C, X, 1 -> ~C | X
return getNode(ISD::OR, VT,
getNode(ISD::XOR, N1.getValueType(), N1,
getConstant(1, N1.getValueType())), N2);
else // select C, X, 0 -> C & X
return getNode(ISD::AND, VT, N1, N2);
}
if (N1 == N2) // X ? X : Y --> X ? 1 : Y --> X | Y
return getNode(ISD::OR, VT, N1, N3);
if (N1 == N3) // X ? Y : X --> X ? Y : 0 --> X & Y
return getNode(ISD::AND, VT, N1, N2);
}
// If this is a selectcc, check to see if we can simplify the result.
if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(N1)) {
if (ConstantFPSDNode *CFP =
dyn_cast<ConstantFPSDNode>(SetCC->getOperand(1)))
if (CFP->getValue() == 0.0) { // Allow either -0.0 or 0.0
// select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
if ((SetCC->getCondition() == ISD::SETGE ||
SetCC->getCondition() == ISD::SETGT) &&
N2 == SetCC->getOperand(0) && N3.getOpcode() == ISD::FNEG &&
N3.getOperand(0) == N2)
return getNode(ISD::FABS, VT, N2);
// select (setl[te] X, +/-0.0), fneg(X), X -> fabs
if ((SetCC->getCondition() == ISD::SETLT ||
SetCC->getCondition() == ISD::SETLE) &&
N3 == SetCC->getOperand(0) && N2.getOpcode() == ISD::FNEG &&
N2.getOperand(0) == N3)
return getNode(ISD::FABS, VT, N3);
}
// select (setlt X, 0), A, 0 -> and (sra X, size(X)-1, A)
if (ConstantSDNode *CN =
dyn_cast<ConstantSDNode>(SetCC->getOperand(1)))
if (CN->getValue() == 0 && N3C && N3C->getValue() == 0)
if (SetCC->getCondition() == ISD::SETLT) {
MVT::ValueType XType = SetCC->getOperand(0).getValueType();
MVT::ValueType AType = N2.getValueType();
if (XType >= AType) {
SDOperand Shift = getNode(ISD::SRA, XType, SetCC->getOperand(0),
getConstant(MVT::getSizeInBits(XType)-1,
TLI.getShiftAmountTy()));
if (XType > AType)
Shift = getNode(ISD::TRUNCATE, AType, Shift);
return getNode(ISD::AND, AType, Shift, N2);
}
}
}
break;
case ISD::BRCOND:
if (N2C)
if (N2C->getValue()) // Unconditional branch
return getNode(ISD::BR, MVT::Other, N1, N3);
else
return N1; // Never-taken branch
break;
// FIXME: figure out how to safely handle things like
// int foo(int x) { return 1 << (x & 255); }
// int bar() { return foo(256); }
#if 0
case ISD::SRA_PARTS:
case ISD::SRL_PARTS:
case ISD::SHL_PARTS:
if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG &&
cast<MVTSDNode>(N3)->getExtraValueType() != MVT::i1)
return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
else if (N3.getOpcode() == ISD::AND)
if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) {
// If the and is only masking out bits that cannot effect the shift,
// eliminate the and.
unsigned NumBits = MVT::getSizeInBits(VT)*2;
if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1)
return getNode(Opcode, VT, N1, N2, N3.getOperand(0));
}
break;
#endif
}
SDNode *N = new SDNode(Opcode, N1, N2, N3);
switch (Opcode) {
default:
N->setValueTypes(VT);
break;
case ISD::DYNAMIC_STACKALLOC: // DYNAMIC_STACKALLOC produces pointer and chain
N->setValueTypes(VT, MVT::Other);
break;
case ISD::SRA_PARTS:
case ISD::SRL_PARTS:
case ISD::SHL_PARTS: {
std::vector<MVT::ValueType> V(N->getNumOperands()-1, VT);
N->setValueTypes(V);
break;
}
}
// FIXME: memoize NODES
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
std::vector<SDOperand> &Children) {
switch (Children.size()) {
case 0: return getNode(Opcode, VT);
case 1: return getNode(Opcode, VT, Children[0]);
case 2: return getNode(Opcode, VT, Children[0], Children[1]);
case 3: return getNode(Opcode, VT, Children[0], Children[1], Children[2]);
default: break;
}
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(Children[1].Val);
switch (Opcode) {
default: break;
case ISD::BRCONDTWOWAY:
if (N1C)
if (N1C->getValue()) // Unconditional branch to true dest.
return getNode(ISD::BR, MVT::Other, Children[0], Children[2]);
else // Unconditional branch to false dest.
return getNode(ISD::BR, MVT::Other, Children[0], Children[3]);
break;
}
// FIXME: MEMOIZE!!
SDNode *N = new SDNode(Opcode, Children);
if (Opcode != ISD::ADD_PARTS && Opcode != ISD::SUB_PARTS) {
N->setValueTypes(VT);
} else {
std::vector<MVT::ValueType> V(N->getNumOperands()/2, VT);
N->setValueTypes(V);
}
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1,
MVT::ValueType EVT) {
switch (Opcode) {
default: assert(0 && "Bad opcode for this accessor!");
case ISD::FP_ROUND_INREG:
assert(VT == N1.getValueType() && "Not an inreg round!");
assert(MVT::isFloatingPoint(VT) && MVT::isFloatingPoint(EVT) &&
"Cannot FP_ROUND_INREG integer types");
if (EVT == VT) return N1; // Not actually rounding
assert(EVT < VT && "Not rounding down!");
if (isa<ConstantFPSDNode>(N1))
return getNode(ISD::FP_EXTEND, VT, getNode(ISD::FP_ROUND, EVT, N1));
break;
case ISD::SIGN_EXTEND_INREG:
assert(VT == N1.getValueType() && "Not an inreg extend!");
assert(MVT::isInteger(VT) && MVT::isInteger(EVT) &&
"Cannot *_EXTEND_INREG FP types");
if (EVT == VT) return N1; // Not actually extending
assert(EVT < VT && "Not extending!");
// Extending a constant? Just return the extended constant.
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) {
SDOperand Tmp = getNode(ISD::TRUNCATE, EVT, N1);
return getNode(ISD::SIGN_EXTEND, VT, Tmp);
}
// If we are sign extending an extension, use the original source.
if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG)
if (cast<MVTSDNode>(N1)->getExtraValueType() <= EVT)
return N1;
// If we are sign extending a sextload, return just the load.
if (N1.getOpcode() == ISD::SEXTLOAD && Opcode == ISD::SIGN_EXTEND_INREG)
if (cast<MVTSDNode>(N1)->getExtraValueType() <= EVT)
return N1;
// If we are extending the result of a setcc, and we already know the
// contents of the top bits, eliminate the extension.
if (N1.getOpcode() == ISD::SETCC &&
TLI.getSetCCResultContents() ==
TargetLowering::ZeroOrNegativeOneSetCCResult)
return N1;
// If we are sign extending the result of an (and X, C) operation, and we
// know the extended bits are zeros already, don't do the extend.
if (N1.getOpcode() == ISD::AND)
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
uint64_t Mask = N1C->getValue();
unsigned NumBits = MVT::getSizeInBits(EVT);
if ((Mask & (~0ULL << (NumBits-1))) == 0)
return N1;
}
break;
}
EVTStruct NN;
NN.Opcode = Opcode;
NN.VT = VT;
NN.EVT = EVT;
NN.Ops.push_back(N1);
SDNode *&N = MVTSDNodes[NN];
if (N) return SDOperand(N, 0);
N = new MVTSDNode(Opcode, VT, N1, EVT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1,
SDOperand N2, MVT::ValueType EVT) {
switch (Opcode) {
default: assert(0 && "Bad opcode for this accessor!");
case ISD::EXTLOAD:
case ISD::SEXTLOAD:
case ISD::ZEXTLOAD:
// If they are asking for an extending load from/to the same thing, return a
// normal load.
if (VT == EVT)
return getNode(ISD::LOAD, VT, N1, N2);
assert(EVT < VT && "Should only be an extending load, not truncating!");
assert((Opcode == ISD::EXTLOAD || MVT::isInteger(VT)) &&
"Cannot sign/zero extend a FP load!");
assert(MVT::isInteger(VT) == MVT::isInteger(EVT) &&
"Cannot convert from FP to Int or Int -> FP!");
break;
}
EVTStruct NN;
NN.Opcode = Opcode;
NN.VT = VT;
NN.EVT = EVT;
NN.Ops.push_back(N1);
NN.Ops.push_back(N2);
SDNode *&N = MVTSDNodes[NN];
if (N) return SDOperand(N, 0);
N = new MVTSDNode(Opcode, VT, MVT::Other, N1, N2, EVT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1,
SDOperand N2, SDOperand N3, MVT::ValueType EVT) {
switch (Opcode) {
default: assert(0 && "Bad opcode for this accessor!");
case ISD::TRUNCSTORE:
#if 0 // FIXME: If the target supports EVT natively, convert to a truncate/store
// If this is a truncating store of a constant, convert to the desired type
// and store it instead.
if (isa<Constant>(N1)) {
SDOperand Op = getNode(ISD::TRUNCATE, EVT, N1);
if (isa<Constant>(Op))
N1 = Op;
}
// Also for ConstantFP?
#endif
if (N1.getValueType() == EVT) // Normal store?
return getNode(ISD::STORE, VT, N1, N2, N3);
assert(N2.getValueType() > EVT && "Not a truncation?");
assert(MVT::isInteger(N2.getValueType()) == MVT::isInteger(EVT) &&
"Can't do FP-INT conversion!");
break;
}
EVTStruct NN;
NN.Opcode = Opcode;
NN.VT = VT;
NN.EVT = EVT;
NN.Ops.push_back(N1);
NN.Ops.push_back(N2);
NN.Ops.push_back(N3);
SDNode *&N = MVTSDNodes[NN];
if (N) return SDOperand(N, 0);
N = new MVTSDNode(Opcode, VT, N1, N2, N3, EVT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
/// hasNUsesOfValue - Return true if there are exactly NUSES uses of the
/// indicated value. This method ignores uses of other values defined by this
/// operation.
bool SDNode::hasNUsesOfValue(unsigned NUses, unsigned Value) {
assert(Value < getNumValues() && "Bad value!");
// If there is only one value, this is easy.
if (getNumValues() == 1)
return use_size() == NUses;
if (Uses.size() < NUses) return false;
SDOperand TheValue(this, Value);
std::set<SDNode*> UsersHandled;
for (std::vector<SDNode*>::iterator UI = Uses.begin(), E = Uses.end();
UI != E; ++UI) {
SDNode *User = *UI;
if (User->getNumOperands() == 1 ||
UsersHandled.insert(User).second) // First time we've seen this?
for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i)
if (User->getOperand(i) == TheValue) {
if (NUses == 0)
return false; // too many uses
--NUses;
}
}
// Found exactly the right number of uses?
return NUses == 0;
}
const char *SDNode::getOperationName() const {
switch (getOpcode()) {
default: return "<<Unknown>>";
case ISD::PCMARKER: return "PCMarker";
case ISD::EntryToken: return "EntryToken";
case ISD::TokenFactor: return "TokenFactor";
case ISD::Constant: return "Constant";
case ISD::ConstantFP: return "ConstantFP";
case ISD::GlobalAddress: return "GlobalAddress";
case ISD::FrameIndex: return "FrameIndex";
case ISD::BasicBlock: return "BasicBlock";
case ISD::ExternalSymbol: return "ExternalSymbol";
case ISD::ConstantPool: return "ConstantPoolIndex";
case ISD::CopyToReg: return "CopyToReg";
case ISD::CopyFromReg: return "CopyFromReg";
case ISD::ImplicitDef: return "ImplicitDef";
case ISD::UNDEF: return "undef";
// Unary operators
case ISD::FABS: return "fabs";
case ISD::FNEG: return "fneg";
// Binary operators
case ISD::ADD: return "add";
case ISD::SUB: return "sub";
case ISD::MUL: return "mul";
case ISD::MULHU: return "mulhu";
case ISD::MULHS: return "mulhs";
case ISD::SDIV: return "sdiv";
case ISD::UDIV: return "udiv";
case ISD::SREM: return "srem";
case ISD::UREM: return "urem";
case ISD::AND: return "and";
case ISD::OR: return "or";
case ISD::XOR: return "xor";
case ISD::SHL: return "shl";
case ISD::SRA: return "sra";
case ISD::SRL: return "srl";
case ISD::SELECT: return "select";
case ISD::ADD_PARTS: return "add_parts";
case ISD::SUB_PARTS: return "sub_parts";
case ISD::SHL_PARTS: return "shl_parts";
case ISD::SRA_PARTS: return "sra_parts";
case ISD::SRL_PARTS: return "srl_parts";
// Conversion operators.
case ISD::SIGN_EXTEND: return "sign_extend";
case ISD::ZERO_EXTEND: return "zero_extend";
case ISD::SIGN_EXTEND_INREG: return "sign_extend_inreg";
case ISD::TRUNCATE: return "truncate";
case ISD::FP_ROUND: return "fp_round";
case ISD::FP_ROUND_INREG: return "fp_round_inreg";
case ISD::FP_EXTEND: return "fp_extend";
case ISD::SINT_TO_FP: return "sint_to_fp";
case ISD::UINT_TO_FP: return "uint_to_fp";
case ISD::FP_TO_SINT: return "fp_to_sint";
case ISD::FP_TO_UINT: return "fp_to_uint";
// Control flow instructions
case ISD::BR: return "br";
case ISD::BRCOND: return "brcond";
case ISD::BRCONDTWOWAY: return "brcondtwoway";
case ISD::RET: return "ret";
case ISD::CALL: return "call";
case ISD::ADJCALLSTACKDOWN: return "adjcallstackdown";
case ISD::ADJCALLSTACKUP: return "adjcallstackup";
// Other operators
case ISD::LOAD: return "load";
case ISD::STORE: return "store";
case ISD::EXTLOAD: return "extload";
case ISD::SEXTLOAD: return "sextload";
case ISD::ZEXTLOAD: return "zextload";
case ISD::TRUNCSTORE: return "truncstore";
case ISD::DYNAMIC_STACKALLOC: return "dynamic_stackalloc";
case ISD::EXTRACT_ELEMENT: return "extract_element";
case ISD::BUILD_PAIR: return "build_pair";
case ISD::MEMSET: return "memset";
case ISD::MEMCPY: return "memcpy";
case ISD::MEMMOVE: return "memmove";
case ISD::SETCC:
const SetCCSDNode *SetCC = cast<SetCCSDNode>(this);
switch (SetCC->getCondition()) {
default: assert(0 && "Unknown setcc condition!");
case ISD::SETOEQ: return "setcc:setoeq";
case ISD::SETOGT: return "setcc:setogt";
case ISD::SETOGE: return "setcc:setoge";
case ISD::SETOLT: return "setcc:setolt";
case ISD::SETOLE: return "setcc:setole";
case ISD::SETONE: return "setcc:setone";
case ISD::SETO: return "setcc:seto";
case ISD::SETUO: return "setcc:setuo";
case ISD::SETUEQ: return "setcc:setue";
case ISD::SETUGT: return "setcc:setugt";
case ISD::SETUGE: return "setcc:setuge";
case ISD::SETULT: return "setcc:setult";
case ISD::SETULE: return "setcc:setule";
case ISD::SETUNE: return "setcc:setune";
case ISD::SETEQ: return "setcc:seteq";
case ISD::SETGT: return "setcc:setgt";
case ISD::SETGE: return "setcc:setge";
case ISD::SETLT: return "setcc:setlt";
case ISD::SETLE: return "setcc:setle";
case ISD::SETNE: return "setcc:setne";
}
}
}
void SDNode::dump() const {
std::cerr << (void*)this << ": ";
for (unsigned i = 0, e = getNumValues(); i != e; ++i) {
if (i) std::cerr << ",";
if (getValueType(i) == MVT::Other)
std::cerr << "ch";
else
std::cerr << MVT::getValueTypeString(getValueType(i));
}
std::cerr << " = " << getOperationName();
std::cerr << " ";
for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
if (i) std::cerr << ", ";
std::cerr << (void*)getOperand(i).Val;
if (unsigned RN = getOperand(i).ResNo)
std::cerr << ":" << RN;
}
if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(this)) {
std::cerr << "<" << CSDN->getValue() << ">";
} else if (const ConstantFPSDNode *CSDN = dyn_cast<ConstantFPSDNode>(this)) {
std::cerr << "<" << CSDN->getValue() << ">";
} else if (const GlobalAddressSDNode *GADN =
dyn_cast<GlobalAddressSDNode>(this)) {
std::cerr << "<";
WriteAsOperand(std::cerr, GADN->getGlobal()) << ">";
} else if (const FrameIndexSDNode *FIDN = dyn_cast<FrameIndexSDNode>(this)) {
std::cerr << "<" << FIDN->getIndex() << ">";
} else if (const ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(this)){
std::cerr << "<" << CP->getIndex() << ">";
} else if (const BasicBlockSDNode *BBDN = dyn_cast<BasicBlockSDNode>(this)) {
std::cerr << "<";
const Value *LBB = (const Value*)BBDN->getBasicBlock()->getBasicBlock();
if (LBB)
std::cerr << LBB->getName() << " ";
std::cerr << (const void*)BBDN->getBasicBlock() << ">";
} else if (const RegSDNode *C2V = dyn_cast<RegSDNode>(this)) {
std::cerr << "<reg #" << C2V->getReg() << ">";
} else if (const ExternalSymbolSDNode *ES =
dyn_cast<ExternalSymbolSDNode>(this)) {
std::cerr << "'" << ES->getSymbol() << "'";
} else if (const MVTSDNode *M = dyn_cast<MVTSDNode>(this)) {
std::cerr << " - Ty = " << MVT::getValueTypeString(M->getExtraValueType());
}
}
static void DumpNodes(SDNode *N, unsigned indent) {
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
if (N->getOperand(i).Val->hasOneUse())
DumpNodes(N->getOperand(i).Val, indent+2);
else
std::cerr << "\n" << std::string(indent+2, ' ')
<< (void*)N->getOperand(i).Val << ": <multiple use>";
std::cerr << "\n" << std::string(indent, ' ');
N->dump();
}
void SelectionDAG::dump() const {
std::cerr << "SelectionDAG has " << AllNodes.size() << " nodes:";
std::vector<SDNode*> Nodes(AllNodes);
std::sort(Nodes.begin(), Nodes.end());
for (unsigned i = 0, e = Nodes.size(); i != e; ++i) {
if (!Nodes[i]->hasOneUse() && Nodes[i] != getRoot().Val)
DumpNodes(Nodes[i], 2);
}
DumpNodes(getRoot().Val, 2);
std::cerr << "\n\n";
}
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