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llvm-6502/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
Chris Lattner a8d9cc8705 shift X, 0 -> X 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19453 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-11 04:25:13 +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 <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);
}
/// 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:
ConstantFPs.erase(std::make_pair(cast<ConstantFPSDNode>(N)->getValue(),
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)),
cast<SetCCSDNode>(N)->getCondition()));
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::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.
SDNode *&N = ConstantFPs[std::make_pair(Val, 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, SDOperand N1,
SDOperand N2) {
// These setcc operations always fold.
switch (Cond) {
default: break;
case ISD::SETFALSE:
case ISD::SETFALSE2: return getConstant(0, MVT::i1);
case ISD::SETTRUE:
case ISD::SETTRUE2: return getConstant(1, MVT::i1);
}
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val))
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val)) {
uint64_t C1 = N1C->getValue(), C2 = N2C->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, MVT::i1);
case ISD::SETNE: return getConstant(C1 != C2, MVT::i1);
case ISD::SETULT: return getConstant(C1 < C2, MVT::i1);
case ISD::SETUGT: return getConstant(C1 > C2, MVT::i1);
case ISD::SETULE: return getConstant(C1 <= C2, MVT::i1);
case ISD::SETUGE: return getConstant(C1 >= C2, MVT::i1);
case ISD::SETLT: return getConstant((int64_t)C1 < (int64_t)C2, MVT::i1);
case ISD::SETGT: return getConstant((int64_t)C1 > (int64_t)C2, MVT::i1);
case ISD::SETLE: return getConstant((int64_t)C1 <= (int64_t)C2, MVT::i1);
case ISD::SETGE: return getConstant((int64_t)C1 >= (int64_t)C2, MVT::i1);
}
} else {
// Ensure that the constant occurs on the RHS.
Cond = ISD::getSetCCSwappedOperands(Cond);
std::swap(N1, N2);
}
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, MVT::i1);
case ISD::SETNE: return getConstant(C1 != C2, MVT::i1);
case ISD::SETLT: return getConstant((int64_t)C1 < (int64_t)C2, MVT::i1);
case ISD::SETGT: return getConstant((int64_t)C1 < (int64_t)C2, MVT::i1);
case ISD::SETLE: return getConstant((int64_t)C1 < (int64_t)C2, MVT::i1);
case ISD::SETGE: return getConstant((int64_t)C1 < (int64_t)C2, MVT::i1);
}
} 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), MVT::i1);
unsigned UOF = ISD::getUnorderedFlavor(Cond);
if (UOF == 2) // FP operators that are undefined on NaNs.
return getConstant(ISD::isTrueWhenEqual(Cond), MVT::i1);
if (UOF == ISD::isTrueWhenEqual(Cond))
return getConstant(UOF, MVT::i1);
// 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, N1.getOperand(1), N2.getOperand(1));
if (N1.getOperand(1) == N2.getOperand(1))
return getSetCC(Cond, 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, N1.getOperand(1), N2.getOperand(0));
if (N1.getOperand(1) == N2.getOperand(0))
return getSetCC(Cond, N1.getOperand(1), N2.getOperand(1));
}
}
// Simplify (X+Z) == X --> Z == 0
if (N1.getOperand(0) == N2)
return getSetCC(Cond, N1.getOperand(1),
getConstant(0, N1.getValueType()));
if (N1.getOperand(1) == N2) {
if (isCommutativeBinOp(N1.getOpcode()))
return getSetCC(Cond, N1.getOperand(0),
getConstant(0, N1.getValueType()));
else {
assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!");
// (Z-X) == X --> Z == X<<1
return getSetCC(Cond, N1.getOperand(0),
getNode(ISD::SHL, N2.getValueType(),
N2, getConstant(1, MVT::i8)));
}
}
}
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, N2.getOperand(1),
getConstant(0, N2.getValueType()));
else if (N2.getOperand(1) == N1)
return getSetCC(Cond, N2.getOperand(0),
getConstant(0, N2.getValueType()));
}
}
SetCCSDNode *&N = SetCCs[std::make_pair(std::make_pair(N1, N2), Cond)];
if (N) return SDOperand(N, 0);
N = new SetCCSDNode(Cond, N1, N2);
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);
}
static const Type *getTypeFor(MVT::ValueType VT) {
switch (VT) {
default: assert(0 && "Unknown MVT!");
case MVT::i1: return Type::BoolTy;
case MVT::i8: return Type::UByteTy;
case MVT::i16: return Type::UShortTy;
case MVT::i32: return Type::UIntTy;
case MVT::i64: return Type::ULongTy;
case MVT::f32: return Type::FloatTy;
case MVT::f64: return Type::DoubleTy;
}
}
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::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::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::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND)
return getNode(OpOpcode, 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;
}
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);
}
SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2) {
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);
}
}
}
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: This should only be done if the target supports shift
// operations.
if ((C2 & C2-1) == 0) {
SDOperand ShAmt = getConstant(ExactLog2(C2), MVT::i8);
return getNode(ISD::SHL, VT, N1, ShAmt);
}
break;
case ISD::UDIV:
// FIXME: This should only be done if the target supports shift
// operations.
if ((C2 & C2-1) == 0 && C2) {
SDOperand ShAmt = getConstant(ExactLog2(C2), MVT::i8);
return getNode(ISD::SRL, VT, N1, ShAmt);
}
break;
case ISD::SHL:
case ISD::SRL:
case ISD::SRA:
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
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->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::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 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, LL, LR);
}
}
break;
case ISD::XOR:
if (N1 == N2) return getConstant(0, VT); // xor X, Y -> 0
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
}
break;
}
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 (N3C) {
if (N2C->getValue()) // select C, 1, 0 -> C
return N1;
return getNode(ISD::XOR, VT, N1, N3); // select C, 0, 1 -> ~C
}
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);
}
}
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;
}
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;
}
// 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:
// FIXME: MEMOIZE!!
SDNode *N = new SDNode(Opcode, Children);
N->setValueTypes(VT);
AllNodes.push_back(N);
return SDOperand(N, 0);
}
}
const char *SDNode::getOperationName() const {
switch (getOpcode()) {
default: return "<<Unknown>>";
case ISD::EntryToken: return "EntryToken";
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::ADD: return "add";
case ISD::SUB: return "sub";
case ISD::MUL: return "mul";
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::ADDC: return "addc";
case ISD::SUBB: return "subb";
// Conversion operators.
case ISD::SIGN_EXTEND: return "sign_extend";
case ISD::ZERO_EXTEND: return "zero_extend";
case ISD::TRUNCATE: return "truncate";
case ISD::FP_ROUND: return "fp_round";
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::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::DYNAMIC_STACKALLOC: return "dynamic_stackalloc";
case ISD::EXTRACT_ELEMENT: return "extract_element";
case ISD::BUILD_PAIR: return "build_pair";
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 << ",";
switch (getValueType(i)) {
default: assert(0 && "Unknown value type!");
case MVT::i1: std::cerr << "i1"; break;
case MVT::i8: std::cerr << "i8"; break;
case MVT::i16: std::cerr << "i16"; break;
case MVT::i32: std::cerr << "i32"; break;
case MVT::i64: std::cerr << "i64"; break;
case MVT::f32: std::cerr << "f32"; break;
case MVT::f64: std::cerr << "f64"; break;
case MVT::Other: std::cerr << "ch"; break;
}
}
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 CopyRegSDNode *C2V = dyn_cast<CopyRegSDNode>(this)) {
std::cerr << "<reg #" << C2V->getReg() << ">";
} else if (const ExternalSymbolSDNode *ES =
dyn_cast<ExternalSymbolSDNode>(this)) {
std::cerr << "'" << ES->getSymbol() << "'";
}
}
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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