// CalculateComputableValues - Fill in the ComputableValues map through
// analysis of the patterns we are playing with.
void InstrSelectorEmitter::CalculateComputableValues() {
// Loop over all of the patterns, adding them to the ComputableValues map
for (std::map<Record*, Pattern*>::iterator I = Patterns.begin(),
E = Patterns.end(); I != E; ++I)
if (I->second->isResolved()) {
// We don't want to add patterns like R32 = R32. This is a hack working
// around a special case of a general problem, but for now we explicitly
// forbid these patterns. They can never match anyway.
Pattern *P = I->second;
if (!P->getResult() || !P->getTree()->isLeaf() ||
P->getResult() != P->getTree()->getValueRecord())
ComputableValues.addPattern(P);
}
}
/// InstantiateNonterminal - This method takes the nonterminal specified by
/// NT, which should not be completely resolved, clones it, applies ResultTy
/// to its root, then runs the type inference stuff on it. This should
/// produce a newly resolved nonterminal, which we make a record for and
/// return. To be extra fancy and efficient, this only makes one clone for
/// each type it is instantiated with.
Record *InstrSelectorEmitter::InstantiateNonterminal(Pattern *NT,
MVT::ValueType ResultTy) {
assert(!NT->isResolved() && "Nonterminal is already resolved!");
// Check to see if we have already instantiated this pair...
Record* &Slot = InstantiatedNTs[std::make_pair(NT, ResultTy)];
if (Slot) return Slot;
Record *New = new Record(NT->getRecord()->getName()+"_"+getName(ResultTy));
// Copy over the superclasses...
const std::vector<Record*> &SCs = NT->getRecord()->getSuperClasses();
for (unsigned i = 0, e = SCs.size(); i != e; ++i)
New->addSuperClass(SCs[i]);
DEBUG(std::cerr << " Nonterminal '" << NT->getRecord()->getName()
<< "' for type '" << getName(ResultTy) << "', producing '"
<< New->getName() << "'\n");
// Copy the pattern...
Pattern *NewPat = NT->clone(New);
// Apply the type to the root...
NewPat->getTree()->updateNodeType(ResultTy, New->getName());
// Infer types...
NewPat->InferAllTypes();
// Make sure everything is good to go now...
if (!NewPat->isResolved())
NewPat->error("Instantiating nonterminal did not resolve all types!");
// Add the pattern to the patterns map, add the record to the RecordKeeper,
// return the new record.
Patterns[New] = NewPat;
Records.addDef(New);
return Slot = New;
}
void InstrSelectorEmitter::run(std::ostream &OS) {
// Type-check all of the node types to ensure we "understand" them.
ReadNodeTypes();
// Read in all of the nonterminals, instructions, and expanders...
ReadNonterminals();
ReadInstructionPatterns();
ReadExpanderPatterns();
// Instantiate any unresolved nonterminals with information from the context
// that they are used in.
InstantiateNonterminals();
// Clear InstantiatedNTs, we don't need it anymore...
InstantiatedNTs.clear();
DEBUG(std::cerr << "Patterns acquired:\n");
for (std::map<Record*, Pattern*>::iterator I = Patterns.begin(),
E = Patterns.end(); I != E; ++I)
if (I->second->isResolved())
DEBUG(std::cerr << " " << *I->second << "\n");
CalculateComputableValues();
OS << "#include \"llvm/CodeGen/MachineInstrBuilder.h\"\n";
EmitSourceFileHeader("Instruction Selector for the " + Target.getName() +
" target", OS);
// Output the slot number enums...
OS << "\nenum { // Slot numbers...\n"
<< " LastBuiltinSlot = ISD::NumBuiltinSlots-1, // Start numbering here\n";
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I)
OS << " " << I->first << "_Slot,\n";
OS << " NumSlots\n};\n\n// Reduction value typedefs...\n";
// Output the reduction value typedefs...
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I) {
OS << "typedef ReducedValue<unsigned, " << I->first
<< "_Slot> ReducedValue_" << I->first << ";\n";
}
// Output the pattern enums...
OS << "\n\n"
<< "enum { // Patterns...\n"
<< " NotComputed = 0,\n"
<< " NoMatchPattern, \n";
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I) {
OS << " // " << I->first << " patterns...\n";
for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
E = I->second.end(); J != E; ++J)
for (unsigned i = 0, e = J->second.size(); i != e; ++i)
OS << " " << J->second[i]->getRecord()->getName() << "_Pattern,\n";
}
OS << "};\n\n";
//===--------------------------------------------------------------------===//
// Emit the class definition...
//
OS << "namespace {\n"
<< " class " << Target.getName() << "ISel {\n"
<< " SelectionDAG &DAG;\n"
<< " public:\n"
<< " " << Target.getName () << "ISel(SelectionDAG &D) : DAG(D) {}\n"
<< " void generateCode();\n"
<< " private:\n"
<< " unsigned makeAnotherReg(const TargetRegisterClass *RC) {\n"
<< " return DAG.getMachineFunction().getSSARegMap()->createVirt"
"ualRegister(RC);\n"
<< " }\n\n"
<< " // DAG matching methods for classes... all of these methods"
" return the cost\n"
<< " // of producing a value of the specified class and type, which"
" also gets\n"
<< " // added to the DAG node.\n";
// Output all of the matching prototypes for slots...
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I)
OS << " unsigned Match_" << I->first << "(SelectionDAGNode *N);\n";
OS << "\n // DAG matching methods for DAG nodes...\n";
// Output all of the matching prototypes for slot/node pairs
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I)
for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
E = I->second.end(); J != E; ++J)
OS << " unsigned Match_" << I->first << "_" << getNodeName(J->first)
<< "(SelectionDAGNode *N);\n";
// Output all of the dag reduction methods prototypes...
OS << "\n // DAG reduction methods...\n";
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I)
OS << " ReducedValue_" << I->first << " *Reduce_" << I->first
<< "(SelectionDAGNode *N,\n" << std::string(27+2*I->first.size(), ' ')
<< "MachineBasicBlock *MBB);\n";
OS << " };\n}\n\n";
// Emit the generateCode entry-point...
OS << "void " << Target.getName () << "ISel::generateCode() {\n"
<< " SelectionDAGNode *Root = DAG.getRoot();\n"
<< " assert(Root->getValueType() == MVT::isVoid && "
"\"Root of DAG produces value??\");\n\n"
<< " std::cerr << \"\\n\";\n"
<< " unsigned Cost = Match_Void_void(Root);\n"
<< " if (Cost >= ~0U >> 1) {\n"
<< " std::cerr << \"Match failed!\\n\";\n"
<< " Root->dump();\n"
<< " abort();\n"
<< " }\n\n"
<< " std::cerr << \"Total DAG Cost: \" << Cost << \"\\n\\n\";\n\n"
<< " Reduce_Void_void(Root, 0);\n"
<< "}\n\n"
<< "//===" << std::string(70, '-') << "===//\n"
<< "// Matching methods...\n"
<< "//\n\n";
//===--------------------------------------------------------------------===//
// Emit all of the matcher methods...
//
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I) {
const std::string &SlotName = I->first;
OS << "unsigned " << Target.getName() << "ISel::Match_" << SlotName
<< "(SelectionDAGNode *N) {\n"
<< " assert(N->getValueType() == MVT::"
<< getEnumName((*I->second.begin()).second[0]->getTree()->getType())
<< ");\n" << " // If we already have a cost available for " << SlotName
<< " use it!\n"
<< " if (N->getPatternFor(" << SlotName << "_Slot))\n"
<< " return N->getCostFor(" << SlotName << "_Slot);\n\n"
<< " unsigned Cost;\n"
<< " switch (N->getNodeType()) {\n"
<< " default: Cost = ~0U >> 1; // Match failed\n"
<< " N->setPatternCostFor(" << SlotName << "_Slot, NoMatchPattern, Cost, NumSlots);\n"
<< " break;\n";
for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
E = I->second.end(); J != E; ++J)
if (!J->first->isSubClassOf("Nonterminal"))
OS << " case ISD::" << getNodeName(J->first) << ":\tCost = Match_"
<< SlotName << "_" << getNodeName(J->first) << "(N); break;\n";
OS << " }\n"; // End of the switch statement
// Emit any patterns which have a nonterminal leaf as the RHS. These may
// match multiple root nodes, so they cannot be handled with the switch...
for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
E = I->second.end(); J != E; ++J)
if (J->first->isSubClassOf("Nonterminal")) {
OS << " unsigned " << J->first->getName() << "_Cost = Match_"
<< getNodeName(J->first) << "(N);\n"
<< " if (" << getNodeName(J->first) << "_Cost < Cost) Cost = "
<< getNodeName(J->first) << "_Cost;\n";
}
OS << " return Cost;\n}\n\n";
for (PatternOrganizer::NodesForSlot::iterator J = I->second.begin(),
E = I->second.end(); J != E; ++J) {
Record *Operator = J->first;
bool isNonterm = Operator->isSubClassOf("Nonterminal");
if (!isNonterm) {
OS << "unsigned " << Target.getName() << "ISel::Match_";
if (!isNonterm) OS << SlotName << "_";
OS << getNodeName(Operator) << "(SelectionDAGNode *N) {\n"
<< " unsigned Pattern = NoMatchPattern;\n"
<< " unsigned MinCost = ~0U >> 1;\n";
std::vector<std::pair<Pattern*, TreePatternNode*> > Patterns;
for (unsigned i = 0, e = J->second.size(); i != e; ++i)
Patterns.push_back(std::make_pair(J->second[i],
J->second[i]->getTree()));
EmitMatchCosters(OS, Patterns, "N", 2);
OS << "\n N->setPatternCostFor(" << SlotName
<< "_Slot, Pattern, MinCost, NumSlots);\n"
<< " return MinCost;\n"
<< "}\n";
}
}
}
//===--------------------------------------------------------------------===//
// Emit all of the reducer methods...
//
OS << "\n\n//===" << std::string(70, '-') << "===//\n"
<< "// Reducer methods...\n"
<< "//\n";
for (PatternOrganizer::iterator I = ComputableValues.begin(),
E = ComputableValues.end(); I != E; ++I) {
const std::string &SlotName = I->first;
OS << "ReducedValue_" << SlotName << " *" << Target.getName()
<< "ISel::Reduce_" << SlotName
<< "(SelectionDAGNode *N, MachineBasicBlock *MBB) {\n"
<< " ReducedValue_" << SlotName << " *Val = N->hasValue<ReducedValue_"
<< SlotName << ">(" << SlotName << "_Slot);\n"
<< " if (Val) return Val;\n"
<< " if (N->getBB()) MBB = N->getBB();\n\n"
<< " switch (N->getPatternFor(" << SlotName << "_Slot)) {\n";
// Loop over all of the patterns that can produce a value for this slot...
PatternOrganizer::NodesForSlot &NodesForSlot = I->second;
for (PatternOrganizer::NodesForSlot::iterator J = NodesForSlot.begin(),
E = NodesForSlot.end(); J != E; ++J)
for (unsigned i = 0, e = J->second.size(); i != e; ++i) {
Pattern *P = J->second[i];
OS << " case " << P->getRecord()->getName() << "_Pattern: {\n"
<< " // " << *P << "\n";
// Loop over the operands, reducing them...
std::vector<std::pair<TreePatternNode*, std::string> > Operands;
ReduceAllOperands(P->getTree(), "N", Operands, OS);
// Now that we have reduced all of our operands, and have the values
// that reduction produces, perform the reduction action for this
// pattern.
std::string Result;
// If the pattern produces a register result, generate a new register
// now.
if (Record *R = P->getResult()) {
assert(R->isSubClassOf("RegisterClass") &&
"Only handle register class results so far!");
OS << " unsigned NewReg = makeAnotherReg(" << Target.getName()
<< "::" << R->getName() << "RegisterClass);\n";
Result = "NewReg";
DEBUG(OS << " std::cerr << \"%reg\" << NewReg << \" =\t\";\n");
} else {
DEBUG(OS << " std::cerr << \"\t\t\";\n");
Result = "0";
}
// Print out the pattern that matched...
DEBUG(OS << " std::cerr << \" " << P->getRecord()->getName() <<'"');
DEBUG(for (unsigned i = 0, e = Operands.size(); i != e; ++i)
if (Operands[i].first->isLeaf()) {
Record *RV = Operands[i].first->getValueRecord();
assert(RV->isSubClassOf("RegisterClass") &&
"Only handles registers here so far!");
OS << " << \" %reg\" << " << Operands[i].second
<< "->Val";
} else {
OS << " << ' ' << " << Operands[i].second
<< "->Val";
});
DEBUG(OS << " << \"\\n\";\n");
// Generate the reduction code appropriate to the particular type of
// pattern that this is...
switch (P->getPatternType()) {
case Pattern::Instruction:
// Instruction patterns just emit a single MachineInstr, using BuildMI
OS << " BuildMI(MBB, " << Target.getName() << "::"
<< P->getRecord()->getName() << ", " << Operands.size();
if (P->getResult()) OS << ", NewReg";
OS << ")";
for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
TreePatternNode *Op = Operands[i].first;
if (Op->isLeaf()) {
Record *RV = Op->getValueRecord();
assert(RV->isSubClassOf("RegisterClass") &&
"Only handles registers here so far!");
OS << ".addReg(" << Operands[i].second << "->Val)";
} else if (Op->getOperator()->getName() == "imm") {
OS << ".addZImm(" << Operands[i].second << "->Val)";
} else if (Op->getOperator()->getName() == "basicblock") {
OS << ".addMBB(" << Operands[i].second << "->Val)";
} else {
assert(0 && "Unknown value type!");
}
}
OS << ";\n";
break;
case Pattern::Expander: {
// Expander patterns emit one machine instr for each instruction in
// the list of instructions expanded to.
ListInit *Insts = P->getRecord()->getValueAsListInit("Result");
for (unsigned IN = 0, e = Insts->getSize(); IN != e; ++IN) {
DagInit *DIInst = dynamic_cast<DagInit*>(Insts->getElement(IN));
if (!DIInst) P->error("Result list must contain instructions!");
Record *InstRec = DIInst->getNodeType();
Pattern *InstPat = getPattern(InstRec);
if (!InstPat || InstPat->getPatternType() != Pattern::Instruction)
P->error("Instruction list must contain Instruction patterns!");
bool hasResult = InstPat->getResult() != 0;
if (InstPat->getNumArgs() != DIInst->getNumArgs()-hasResult) {
P->error("Incorrect number of arguments specified for inst '" +
InstPat->getRecord()->getName() + "' in result list!");
}
// Start emission of the instruction...
OS << " BuildMI(MBB, " << Target.getName() << "::"
<< InstRec->getName() << ", "
<< DIInst->getNumArgs()-hasResult;
// Emit register result if necessary..
if (hasResult) {
std::string ArgNameVal =
getArgName(P, DIInst->getArgName(0), Operands);
PrintExpanderOperand(DIInst->getArg(0), ArgNameVal,
InstPat->getResultNode(), P, false,
OS << ", ");
}
OS << ")";
for (unsigned i = hasResult, e = DIInst->getNumArgs(); i != e; ++i){
std::string ArgNameVal =
getArgName(P, DIInst->getArgName(i), Operands);
PrintExpanderOperand(DIInst->getArg(i), ArgNameVal,
InstPat->getArg(i-hasResult), P, true, OS);
}
OS << ";\n";
}
break;
}
default:
assert(0 && "Reduction of this type of pattern not implemented!");
}
OS << " Val = new ReducedValue_" << SlotName << "(" << Result<<");\n"
<< " break;\n"
<< " }\n";
}
OS << " default: assert(0 && \"Unknown " << SlotName << " pattern!\");\n"
<< " }\n\n N->addValue(Val); // Do not ever recalculate this\n"
<< " return Val;\n}\n\n";
}
// EmitMatchCosters - Given a list of patterns, which all have the same root
// pattern operator, emit an efficient decision tree to decide which one to
// pick. This is structured this way to avoid reevaluations of non-obvious
// subexpressions.
void InstrSelectorEmitter::EmitMatchCosters(std::ostream &OS,
const std::vector<std::pair<Pattern*, TreePatternNode*> > &Patterns,
const std::string &VarPrefix,
unsigned IndentAmt) {
assert(!Patterns.empty() && "No patterns to emit matchers for!");
std::string Indent(IndentAmt, ' ');
// Load all of the operands of the root node into scalars for fast access
const NodeType &ONT = getNodeType(Patterns[0].second->getOperator());
for (unsigned i = 0, e = ONT.ArgTypes.size(); i != e; ++i)
OS << Indent << "SelectionDAGNode *" << VarPrefix << "_Op" << i
<< " = N->getUse(" << i << ");\n";
// Compute the costs of computing the various nonterminals/registers, which
// are directly used at this level.
OS << "\n" << Indent << "// Operand matching costs...\n";
std::set<std::string> ComputedValues; // Avoid duplicate computations...
for (unsigned i = 0, e = Patterns.size(); i != e; ++i) {
TreePatternNode *NParent = Patterns[i].second;
for (unsigned c = 0, e = NParent->getNumChildren(); c != e; ++c) {
TreePatternNode *N = NParent->getChild(c);
if (N->isLeaf()) {
Record *VR = N->getValueRecord();
const std::string &LeafName = VR->getName();
std::string OpName = VarPrefix + "_Op" + utostr(c);
std::string ValName = OpName + "_" + LeafName + "_Cost";
if (!ComputedValues.count(ValName)) {
OS << Indent << "unsigned " << ValName << " = Match_"
<< Pattern::getSlotName(VR) << "(" << OpName << ");\n";
ComputedValues.insert(ValName);
}
}
}
}
OS << "\n";
std::string LocCostName = VarPrefix + "_Cost";
OS << Indent << "unsigned " << LocCostName << "Min = ~0U >> 1;\n"
<< Indent << "unsigned " << VarPrefix << "_PatternMin = NoMatchPattern;\n";
#if 0
// Separate out all of the patterns into groups based on what their top-level
// signature looks like...
std::vector<std::pair<Pattern*, TreePatternNode*> > PatternsLeft(Patterns);
while (!PatternsLeft.empty()) {
// Process all of the patterns that have the same signature as the last
// element...
std::vector<std::pair<Pattern*, TreePatternNode*> > Group;
MoveIdenticalPatterns(PatternsLeft.back().second, PatternsLeft, Group);
assert(!Group.empty() && "Didn't at least pick the source pattern?");
#if 0
OS << "PROCESSING GROUP:\n";
for (unsigned i = 0, e = Group.size(); i != e; ++i)
OS << " " << *Group[i].first << "\n";
OS << "\n\n";
#endif
OS << Indent << "{ // ";
if (Group.size() != 1) {
OS << Group.size() << " size group...\n";
OS << Indent << " unsigned " << VarPrefix << "_Pattern = NoMatch;\n";
} else {
OS << *Group[0].first << "\n";
OS << Indent << " unsigned " << VarPrefix << "_Pattern = "
<< Group[0].first->getRecord()->getName() << "_Pattern;\n";
}
OS << Indent << " unsigned " << LocCostName << " = ";
if (Group.size() == 1)
OS << "1;\n"; // Add inst cost if at individual rec
else
OS << "0;\n";
// Loop over all of the operands, adding in their costs...
TreePatternNode *N = Group[0].second;
const std::vector<TreePatternNode*> &Children = N->getChildren();
// If necessary, emit conditionals to check for the appropriate tree
// structure here...
for (unsigned i = 0, e = Children.size(); i != e; ++i) {
TreePatternNode *C = Children[i];
if (C->isLeaf()) {
// We already calculated the cost for this leaf, add it in now...
OS << Indent << " " << LocCostName << " += "
<< VarPrefix << "_Op" << utostr(i) << "_"
<< C->getValueRecord()->getName() << "_Cost;\n";
} else {
// If it's not a leaf, we have to check to make sure that the current
// node has the appropriate structure, then recurse into it...
OS << Indent << " if (" << VarPrefix << "_Op" << i
<< "->getNodeType() == ISD::" << getNodeName(C->getOperator())
<< ") {\n";
std::vector<std::pair<Pattern*, TreePatternNode*> > SubPatterns;
for (unsigned n = 0, e = Group.size(); n != e; ++n)
SubPatterns.push_back(std::make_pair(Group[n].first,
Group[n].second->getChild(i)));
EmitMatchCosters(OS, SubPatterns, VarPrefix+"_Op"+utostr(i),
IndentAmt + 4);
OS << Indent << " }\n";
}
}
// If the cost for this match is less than the minimum computed cost so far,
// update the minimum cost and selected pattern.
OS << Indent << " if (" << LocCostName << " < " << LocCostName << "Min) { "
<< LocCostName << "Min = " << LocCostName << "; " << VarPrefix
<< "_PatternMin = " << VarPrefix << "_Pattern; }\n";
OS << Indent << "}\n";
}
#endif
for (unsigned i = 0, e = Patterns.size(); i != e; ++i) {
Pattern *P = Patterns[i].first;
TreePatternNode *PTree = P->getTree();
unsigned PatternCost = 1;
// Check to see if there are any non-leaf elements in the pattern. If so,
// we need to emit a predicate for this match.
bool AnyNonLeaf = false;
for (unsigned c = 0, e = PTree->getNumChildren(); c != e; ++c)
if (!PTree->getChild(c)->isLeaf()) {
AnyNonLeaf = true;
break;
}
if (!AnyNonLeaf) { // No predicate necessary, just output a scope...
OS << " {// " << *P << "\n";
} else {
// We need to emit a predicate to make sure the tree pattern matches, do
// so now...
OS << " if (1";
for (unsigned c = 0, e = PTree->getNumChildren(); c != e; ++c)
if (!PTree->getChild(c)->isLeaf())
EmitPatternPredicates(PTree->getChild(c),
VarPrefix + "_Op" + utostr(c), OS);
OS << ") {\n // " << *P << "\n";
}
OS << " unsigned PatCost = " << PatternCost;
for (unsigned c = 0, e = PTree->getNumChildren(); c != e; ++c)
if (PTree->getChild(c)->isLeaf()) {
OS << " + " << VarPrefix << "_Op" << c << "_"
<< PTree->getChild(c)->getValueRecord()->getName() << "_Cost";
} else {
EmitPatternCosts(PTree->getChild(c), VarPrefix + "_Op" + utostr(c), OS);
}
OS << ";\n";
OS << " if (PatCost < MinCost) { MinCost = PatCost; Pattern = "
<< P->getRecord()->getName() << "_Pattern; }\n"
<< " }\n";
}
}