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llvm-project/llvm/utils/TableGen/DAGISelMatcherGen.cpp

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//===- DAGISelMatcherGen.cpp - Matcher generator --------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "DAGISelMatcher.h"
#include "CodeGenDAGPatterns.h"
#include "CodeGenRegisters.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include <utility>
using namespace llvm;
/// getRegisterValueType - Look up and return the ValueType of the specified
/// register. If the register is a member of multiple register classes which
/// have different associated types, return MVT::Other.
static MVT::SimpleValueType getRegisterValueType(Record *R,
const CodeGenTarget &T) {
bool FoundRC = false;
MVT::SimpleValueType VT = MVT::Other;
const CodeGenRegister *Reg = T.getRegBank().getReg(R);
for (const auto &RC : T.getRegBank().getRegClasses()) {
if (!RC.contains(Reg))
continue;
if (!FoundRC) {
FoundRC = true;
const ValueTypeByHwMode &VVT = RC.getValueTypeNum(0);
if (VVT.isSimple())
VT = VVT.getSimple().SimpleTy;
continue;
}
#ifndef NDEBUG
// If this occurs in multiple register classes, they all have to agree.
const ValueTypeByHwMode &T = RC.getValueTypeNum(0);
assert((!T.isSimple() || T.getSimple().SimpleTy == VT) &&
"ValueType mismatch between register classes for this register");
#endif
}
return VT;
}
namespace {
class MatcherGen {
const PatternToMatch &Pattern;
const CodeGenDAGPatterns &CGP;
/// PatWithNoTypes - This is a clone of Pattern.getSrcPattern() that starts
/// out with all of the types removed. This allows us to insert type checks
/// as we scan the tree.
TreePatternNodePtr PatWithNoTypes;
/// VariableMap - A map from variable names ('$dst') to the recorded operand
/// number that they were captured as. These are biased by 1 to make
/// insertion easier.
StringMap<unsigned> VariableMap;
/// This maintains the recorded operand number that OPC_CheckComplexPattern
/// drops each sub-operand into. We don't want to insert these into
/// VariableMap because that leads to identity checking if they are
/// encountered multiple times. Biased by 1 like VariableMap for
/// consistency.
StringMap<unsigned> NamedComplexPatternOperands;
/// NextRecordedOperandNo - As we emit opcodes to record matched values in
/// the RecordedNodes array, this keeps track of which slot will be next to
/// record into.
unsigned NextRecordedOperandNo;
/// MatchedChainNodes - This maintains the position in the recorded nodes
/// array of all of the recorded input nodes that have chains.
SmallVector<unsigned, 2> MatchedChainNodes;
/// MatchedComplexPatterns - This maintains a list of all of the
/// ComplexPatterns that we need to check. The second element of each pair
/// is the recorded operand number of the input node.
SmallVector<std::pair<const TreePatternNode*,
unsigned>, 2> MatchedComplexPatterns;
/// PhysRegInputs - List list has an entry for each explicitly specified
/// physreg input to the pattern. The first elt is the Register node, the
/// second is the recorded slot number the input pattern match saved it in.
SmallVector<std::pair<Record*, unsigned>, 2> PhysRegInputs;
/// Matcher - This is the top level of the generated matcher, the result.
Matcher *TheMatcher;
/// CurPredicate - As we emit matcher nodes, this points to the latest check
/// which should have future checks stuck into its Next position.
Matcher *CurPredicate;
public:
MatcherGen(const PatternToMatch &pattern, const CodeGenDAGPatterns &cgp);
bool EmitMatcherCode(unsigned Variant);
void EmitResultCode();
Matcher *GetMatcher() const { return TheMatcher; }
private:
void AddMatcher(Matcher *NewNode);
void InferPossibleTypes(unsigned ForceMode);
// Matcher Generation.
void EmitMatchCode(const TreePatternNode *N, TreePatternNode *NodeNoTypes,
unsigned ForceMode);
void EmitLeafMatchCode(const TreePatternNode *N);
void EmitOperatorMatchCode(const TreePatternNode *N,
TreePatternNode *NodeNoTypes,
unsigned ForceMode);
/// If this is the first time a node with unique identifier Name has been
/// seen, record it. Otherwise, emit a check to make sure this is the same
/// node. Returns true if this is the first encounter.
bool recordUniqueNode(ArrayRef<std::string> Names);
// Result Code Generation.
unsigned getNamedArgumentSlot(StringRef Name) {
unsigned VarMapEntry = VariableMap[Name];
assert(VarMapEntry != 0 &&
"Variable referenced but not defined and not caught earlier!");
return VarMapEntry-1;
}
void EmitResultOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps);
void EmitResultOfNamedOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps);
void EmitResultLeafAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps);
void EmitResultInstructionAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps);
void EmitResultSDNodeXFormAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps);
};
} // end anonymous namespace
MatcherGen::MatcherGen(const PatternToMatch &pattern,
const CodeGenDAGPatterns &cgp)
: Pattern(pattern), CGP(cgp), NextRecordedOperandNo(0),
TheMatcher(nullptr), CurPredicate(nullptr) {
// We need to produce the matcher tree for the patterns source pattern. To do
// this we need to match the structure as well as the types. To do the type
// matching, we want to figure out the fewest number of type checks we need to
// emit. For example, if there is only one integer type supported by a
// target, there should be no type comparisons at all for integer patterns!
//
// To figure out the fewest number of type checks needed, clone the pattern,
// remove the types, then perform type inference on the pattern as a whole.
// If there are unresolved types, emit an explicit check for those types,
// apply the type to the tree, then rerun type inference. Iterate until all
// types are resolved.
//
PatWithNoTypes = Pattern.getSrcPattern()->clone();
PatWithNoTypes->RemoveAllTypes();
// If there are types that are manifestly known, infer them.
InferPossibleTypes(Pattern.ForceMode);
}
/// InferPossibleTypes - As we emit the pattern, we end up generating type
/// checks and applying them to the 'PatWithNoTypes' tree. As we do this, we
/// want to propagate implied types as far throughout the tree as possible so
/// that we avoid doing redundant type checks. This does the type propagation.
void MatcherGen::InferPossibleTypes(unsigned ForceMode) {
// TP - Get *SOME* tree pattern, we don't care which. It is only used for
// diagnostics, which we know are impossible at this point.
TreePattern &TP = *CGP.pf_begin()->second;
TP.getInfer().CodeGen = true;
TP.getInfer().ForceMode = ForceMode;
bool MadeChange = true;
while (MadeChange)
MadeChange = PatWithNoTypes->ApplyTypeConstraints(TP,
true/*Ignore reg constraints*/);
}
/// AddMatcher - Add a matcher node to the current graph we're building.
void MatcherGen::AddMatcher(Matcher *NewNode) {
if (CurPredicate)
CurPredicate->setNext(NewNode);
else
TheMatcher = NewNode;
CurPredicate = NewNode;
}
//===----------------------------------------------------------------------===//
// Pattern Match Generation
//===----------------------------------------------------------------------===//
/// EmitLeafMatchCode - Generate matching code for leaf nodes.
void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
assert(N->isLeaf() && "Not a leaf?");
// Direct match against an integer constant.
if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) {
// If this is the root of the dag we're matching, we emit a redundant opcode
// check to ensure that this gets folded into the normal top-level
// OpcodeSwitch.
if (N == Pattern.getSrcPattern()) {
const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("imm"));
AddMatcher(new CheckOpcodeMatcher(NI));
}
return AddMatcher(new CheckIntegerMatcher(II->getValue()));
}
// An UnsetInit represents a named node without any constraints.
if (isa<UnsetInit>(N->getLeafValue())) {
assert(N->hasName() && "Unnamed ? leaf");
return;
}
DefInit *DI = dyn_cast<DefInit>(N->getLeafValue());
if (!DI) {
errs() << "Unknown leaf kind: " << *N << "\n";
abort();
}
Record *LeafRec = DI->getDef();
// A ValueType leaf node can represent a register when named, or itself when
// unnamed.
if (LeafRec->isSubClassOf("ValueType")) {
// A named ValueType leaf always matches: (add i32:$a, i32:$b).
if (N->hasName())
return;
// An unnamed ValueType as in (sext_inreg GPR:$foo, i8).
return AddMatcher(new CheckValueTypeMatcher(LeafRec->getName()));
}
if (// Handle register references. Nothing to do here, they always match.
LeafRec->isSubClassOf("RegisterClass") ||
LeafRec->isSubClassOf("RegisterOperand") ||
LeafRec->isSubClassOf("PointerLikeRegClass") ||
LeafRec->isSubClassOf("SubRegIndex") ||
// Place holder for SRCVALUE nodes. Nothing to do here.
LeafRec->getName() == "srcvalue")
return;
// If we have a physreg reference like (mul gpr:$src, EAX) then we need to
// record the register
if (LeafRec->isSubClassOf("Register")) {
AddMatcher(new RecordMatcher("physreg input "+LeafRec->getName().str(),
NextRecordedOperandNo));
PhysRegInputs.push_back(std::make_pair(LeafRec, NextRecordedOperandNo++));
return;
}
if (LeafRec->isSubClassOf("CondCode"))
return AddMatcher(new CheckCondCodeMatcher(LeafRec->getName()));
if (LeafRec->isSubClassOf("ComplexPattern")) {
// We can't model ComplexPattern uses that don't have their name taken yet.
// The OPC_CheckComplexPattern operation implicitly records the results.
if (N->getName().empty()) {
std::string S;
raw_string_ostream OS(S);
OS << "We expect complex pattern uses to have names: " << *N;
PrintFatalError(OS.str());
}
// Remember this ComplexPattern so that we can emit it after all the other
// structural matches are done.
unsigned InputOperand = VariableMap[N->getName()] - 1;
MatchedComplexPatterns.push_back(std::make_pair(N, InputOperand));
return;
}
if (LeafRec->getName() == "immAllOnesV") {
// If this is the root of the dag we're matching, we emit a redundant opcode
// check to ensure that this gets folded into the normal top-level
// OpcodeSwitch.
if (N == Pattern.getSrcPattern()) {
const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("build_vector"));
AddMatcher(new CheckOpcodeMatcher(NI));
}
return AddMatcher(new CheckImmAllOnesVMatcher());
}
if (LeafRec->getName() == "immAllZerosV") {
// If this is the root of the dag we're matching, we emit a redundant opcode
// check to ensure that this gets folded into the normal top-level
// OpcodeSwitch.
if (N == Pattern.getSrcPattern()) {
const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("build_vector"));
AddMatcher(new CheckOpcodeMatcher(NI));
}
return AddMatcher(new CheckImmAllZerosVMatcher());
}
errs() << "Unknown leaf kind: " << *N << "\n";
abort();
}
void MatcherGen::EmitOperatorMatchCode(const TreePatternNode *N,
TreePatternNode *NodeNoTypes,
unsigned ForceMode) {
assert(!N->isLeaf() && "Not an operator?");
if (N->getOperator()->isSubClassOf("ComplexPattern")) {
// The "name" of a non-leaf complex pattern (MY_PAT $op1, $op2) is
// "MY_PAT:op1:op2". We should already have validated that the uses are
// consistent.
std::string PatternName = std::string(N->getOperator()->getName());
for (unsigned i = 0; i < N->getNumChildren(); ++i) {
PatternName += ":";
PatternName += N->getChild(i)->getName();
}
if (recordUniqueNode(PatternName)) {
auto NodeAndOpNum = std::make_pair(N, NextRecordedOperandNo - 1);
MatchedComplexPatterns.push_back(NodeAndOpNum);
}
return;
}
const SDNodeInfo &CInfo = CGP.getSDNodeInfo(N->getOperator());
// If this is an 'and R, 1234' where the operation is AND/OR and the RHS is
// a constant without a predicate fn that has more than one bit set, handle
// this as a special case. This is usually for targets that have special
// handling of certain large constants (e.g. alpha with it's 8/16/32-bit
// handling stuff). Using these instructions is often far more efficient
// than materializing the constant. Unfortunately, both the instcombiner
// and the dag combiner can often infer that bits are dead, and thus drop
// them from the mask in the dag. For example, it might turn 'AND X, 255'
// into 'AND X, 254' if it knows the low bit is set. Emit code that checks
// to handle this.
if ((N->getOperator()->getName() == "and" ||
N->getOperator()->getName() == "or") &&
N->getChild(1)->isLeaf() && N->getChild(1)->getPredicateCalls().empty() &&
N->getPredicateCalls().empty()) {
if (IntInit *II = dyn_cast<IntInit>(N->getChild(1)->getLeafValue())) {
if (!isPowerOf2_32(II->getValue())) { // Don't bother with single bits.
// If this is at the root of the pattern, we emit a redundant
// CheckOpcode so that the following checks get factored properly under
// a single opcode check.
if (N == Pattern.getSrcPattern())
AddMatcher(new CheckOpcodeMatcher(CInfo));
// Emit the CheckAndImm/CheckOrImm node.
if (N->getOperator()->getName() == "and")
AddMatcher(new CheckAndImmMatcher(II->getValue()));
else
AddMatcher(new CheckOrImmMatcher(II->getValue()));
// Match the LHS of the AND as appropriate.
AddMatcher(new MoveChildMatcher(0));
EmitMatchCode(N->getChild(0), NodeNoTypes->getChild(0), ForceMode);
AddMatcher(new MoveParentMatcher());
return;
}
}
}
// Check that the current opcode lines up.
AddMatcher(new CheckOpcodeMatcher(CInfo));
// If this node has memory references (i.e. is a load or store), tell the
// interpreter to capture them in the memref array.
if (N->NodeHasProperty(SDNPMemOperand, CGP))
AddMatcher(new RecordMemRefMatcher());
// If this node has a chain, then the chain is operand #0 is the SDNode, and
// the child numbers of the node are all offset by one.
unsigned OpNo = 0;
if (N->NodeHasProperty(SDNPHasChain, CGP)) {
// Record the node and remember it in our chained nodes list.
AddMatcher(new RecordMatcher("'" + N->getOperator()->getName().str() +
"' chained node",
NextRecordedOperandNo));
// Remember all of the input chains our pattern will match.
MatchedChainNodes.push_back(NextRecordedOperandNo++);
// Don't look at the input chain when matching the tree pattern to the
// SDNode.
OpNo = 1;
// If this node is not the root and the subtree underneath it produces a
// chain, then the result of matching the node is also produce a chain.
// Beyond that, this means that we're also folding (at least) the root node
// into the node that produce the chain (for example, matching
// "(add reg, (load ptr))" as a add_with_memory on X86). This is
// problematic, if the 'reg' node also uses the load (say, its chain).
// Graphically:
//
// [LD]
// ^ ^
// | \ DAG's like cheese.
// / |
// / [YY]
// | ^
// [XX]--/
//
// It would be invalid to fold XX and LD. In this case, folding the two
// nodes together would induce a cycle in the DAG, making it a 'cyclic DAG'
// To prevent this, we emit a dynamic check for legality before allowing
// this to be folded.
//
const TreePatternNode *Root = Pattern.getSrcPattern();
if (N != Root) { // Not the root of the pattern.
// If there is a node between the root and this node, then we definitely
// need to emit the check.
bool NeedCheck = !Root->hasChild(N);
// If it *is* an immediate child of the root, we can still need a check if
// the root SDNode has multiple inputs. For us, this means that it is an
// intrinsic, has multiple operands, or has other inputs like chain or
// glue).
if (!NeedCheck) {
const SDNodeInfo &PInfo = CGP.getSDNodeInfo(Root->getOperator());
NeedCheck =
Root->getOperator() == CGP.get_intrinsic_void_sdnode() ||
Root->getOperator() == CGP.get_intrinsic_w_chain_sdnode() ||
Root->getOperator() == CGP.get_intrinsic_wo_chain_sdnode() ||
PInfo.getNumOperands() > 1 ||
PInfo.hasProperty(SDNPHasChain) ||
PInfo.hasProperty(SDNPInGlue) ||
PInfo.hasProperty(SDNPOptInGlue);
}
if (NeedCheck)
AddMatcher(new CheckFoldableChainNodeMatcher());
}
}
// If this node has an output glue and isn't the root, remember it.
if (N->NodeHasProperty(SDNPOutGlue, CGP) &&
N != Pattern.getSrcPattern()) {
// TODO: This redundantly records nodes with both glues and chains.
// Record the node and remember it in our chained nodes list.
AddMatcher(new RecordMatcher("'" + N->getOperator()->getName().str() +
"' glue output node",
NextRecordedOperandNo));
}
// If this node is known to have an input glue or if it *might* have an input
// glue, capture it as the glue input of the pattern.
if (N->NodeHasProperty(SDNPOptInGlue, CGP) ||
N->NodeHasProperty(SDNPInGlue, CGP))
AddMatcher(new CaptureGlueInputMatcher());
for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i, ++OpNo) {
// Get the code suitable for matching this child. Move to the child, check
// it then move back to the parent.
AddMatcher(new MoveChildMatcher(OpNo));
EmitMatchCode(N->getChild(i), NodeNoTypes->getChild(i), ForceMode);
AddMatcher(new MoveParentMatcher());
}
}
bool MatcherGen::recordUniqueNode(ArrayRef<std::string> Names) {
unsigned Entry = 0;
for (const std::string &Name : Names) {
unsigned &VarMapEntry = VariableMap[Name];
if (!Entry)
Entry = VarMapEntry;
assert(Entry == VarMapEntry);
}
bool NewRecord = false;
if (Entry == 0) {
// If it is a named node, we must emit a 'Record' opcode.
std::string WhatFor;
for (const std::string &Name : Names) {
if (!WhatFor.empty())
WhatFor += ',';
WhatFor += "$" + Name;
}
AddMatcher(new RecordMatcher(WhatFor, NextRecordedOperandNo));
Entry = ++NextRecordedOperandNo;
NewRecord = true;
} else {
// If we get here, this is a second reference to a specific name. Since
// we already have checked that the first reference is valid, we don't
// have to recursively match it, just check that it's the same as the
// previously named thing.
AddMatcher(new CheckSameMatcher(Entry-1));
}
for (const std::string &Name : Names)
VariableMap[Name] = Entry;
return NewRecord;
}
void MatcherGen::EmitMatchCode(const TreePatternNode *N,
TreePatternNode *NodeNoTypes,
unsigned ForceMode) {
// If N and NodeNoTypes don't agree on a type, then this is a case where we
// need to do a type check. Emit the check, apply the type to NodeNoTypes and
// reinfer any correlated types.
SmallVector<unsigned, 2> ResultsToTypeCheck;
for (unsigned i = 0, e = NodeNoTypes->getNumTypes(); i != e; ++i) {
if (NodeNoTypes->getExtType(i) == N->getExtType(i)) continue;
NodeNoTypes->setType(i, N->getExtType(i));
InferPossibleTypes(ForceMode);
ResultsToTypeCheck.push_back(i);
}
// If this node has a name associated with it, capture it in VariableMap. If
// we already saw this in the pattern, emit code to verify dagness.
SmallVector<std::string, 4> Names;
if (!N->getName().empty())
Names.push_back(N->getName());
for (const ScopedName &Name : N->getNamesAsPredicateArg()) {
Names.push_back(("pred:" + Twine(Name.getScope()) + ":" + Name.getIdentifier()).str());
}
if (!Names.empty()) {
if (!recordUniqueNode(Names))
return;
}
if (N->isLeaf())
EmitLeafMatchCode(N);
else
EmitOperatorMatchCode(N, NodeNoTypes, ForceMode);
// If there are node predicates for this node, generate their checks.
for (unsigned i = 0, e = N->getPredicateCalls().size(); i != e; ++i) {
const TreePredicateCall &Pred = N->getPredicateCalls()[i];
SmallVector<unsigned, 4> Operands;
if (Pred.Fn.usesOperands()) {
TreePattern *TP = Pred.Fn.getOrigPatFragRecord();
for (unsigned i = 0; i < TP->getNumArgs(); ++i) {
std::string Name =
("pred:" + Twine(Pred.Scope) + ":" + TP->getArgName(i)).str();
Operands.push_back(getNamedArgumentSlot(Name));
}
}
AddMatcher(new CheckPredicateMatcher(Pred.Fn, Operands));
}
for (unsigned i = 0, e = ResultsToTypeCheck.size(); i != e; ++i)
AddMatcher(new CheckTypeMatcher(N->getSimpleType(ResultsToTypeCheck[i]),
ResultsToTypeCheck[i]));
}
/// EmitMatcherCode - Generate the code that matches the predicate of this
/// pattern for the specified Variant. If the variant is invalid this returns
/// true and does not generate code, if it is valid, it returns false.
bool MatcherGen::EmitMatcherCode(unsigned Variant) {
// If the root of the pattern is a ComplexPattern and if it is specified to
// match some number of root opcodes, these are considered to be our variants.
// Depending on which variant we're generating code for, emit the root opcode
// check.
if (const ComplexPattern *CP =
Pattern.getSrcPattern()->getComplexPatternInfo(CGP)) {
const std::vector<Record*> &OpNodes = CP->getRootNodes();
assert(!OpNodes.empty() &&"Complex Pattern must specify what it can match");
if (Variant >= OpNodes.size()) return true;
AddMatcher(new CheckOpcodeMatcher(CGP.getSDNodeInfo(OpNodes[Variant])));
} else {
if (Variant != 0) return true;
}
// Emit the matcher for the pattern structure and types.
EmitMatchCode(Pattern.getSrcPattern(), PatWithNoTypes.get(),
Pattern.ForceMode);
// If the pattern has a predicate on it (e.g. only enabled when a subtarget
// feature is around, do the check).
if (!Pattern.getPredicateCheck().empty())
AddMatcher(new CheckPatternPredicateMatcher(Pattern.getPredicateCheck()));
// Now that we've completed the structural type match, emit any ComplexPattern
// checks (e.g. addrmode matches). We emit this after the structural match
// because they are generally more expensive to evaluate and more difficult to
// factor.
for (unsigned i = 0, e = MatchedComplexPatterns.size(); i != e; ++i) {
auto N = MatchedComplexPatterns[i].first;
// Remember where the results of this match get stuck.
if (N->isLeaf()) {
NamedComplexPatternOperands[N->getName()] = NextRecordedOperandNo + 1;
} else {
unsigned CurOp = NextRecordedOperandNo;
for (unsigned i = 0; i < N->getNumChildren(); ++i) {
NamedComplexPatternOperands[N->getChild(i)->getName()] = CurOp + 1;
CurOp += N->getChild(i)->getNumMIResults(CGP);
}
}
// Get the slot we recorded the value in from the name on the node.
unsigned RecNodeEntry = MatchedComplexPatterns[i].second;
const ComplexPattern &CP = *N->getComplexPatternInfo(CGP);
// Emit a CheckComplexPat operation, which does the match (aborting if it
// fails) and pushes the matched operands onto the recorded nodes list.
AddMatcher(new CheckComplexPatMatcher(CP, RecNodeEntry,
N->getName(), NextRecordedOperandNo));
// Record the right number of operands.
NextRecordedOperandNo += CP.getNumOperands();
if (CP.hasProperty(SDNPHasChain)) {
// If the complex pattern has a chain, then we need to keep track of the
// fact that we just recorded a chain input. The chain input will be
// matched as the last operand of the predicate if it was successful.
++NextRecordedOperandNo; // Chained node operand.
// It is the last operand recorded.
assert(NextRecordedOperandNo > 1 &&
"Should have recorded input/result chains at least!");
MatchedChainNodes.push_back(NextRecordedOperandNo-1);
}
// TODO: Complex patterns can't have output glues, if they did, we'd want
// to record them.
}
return false;
}
//===----------------------------------------------------------------------===//
// Node Result Generation
//===----------------------------------------------------------------------===//
void MatcherGen::EmitResultOfNamedOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps){
assert(!N->getName().empty() && "Operand not named!");
if (unsigned SlotNo = NamedComplexPatternOperands[N->getName()]) {
// Complex operands have already been completely selected, just find the
// right slot ant add the arguments directly.
for (unsigned i = 0; i < N->getNumMIResults(CGP); ++i)
ResultOps.push_back(SlotNo - 1 + i);
return;
}
unsigned SlotNo = getNamedArgumentSlot(N->getName());
// If this is an 'imm' or 'fpimm' node, make sure to convert it to the target
// version of the immediate so that it doesn't get selected due to some other
// node use.
if (!N->isLeaf()) {
StringRef OperatorName = N->getOperator()->getName();
if (OperatorName == "imm" || OperatorName == "fpimm") {
AddMatcher(new EmitConvertToTargetMatcher(SlotNo));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
}
for (unsigned i = 0; i < N->getNumMIResults(CGP); ++i)
ResultOps.push_back(SlotNo + i);
}
void MatcherGen::EmitResultLeafAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps) {
assert(N->isLeaf() && "Must be a leaf");
if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) {
AddMatcher(new EmitIntegerMatcher(II->getValue(), N->getSimpleType(0)));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
// If this is an explicit register reference, handle it.
if (DefInit *DI = dyn_cast<DefInit>(N->getLeafValue())) {
Record *Def = DI->getDef();
if (Def->isSubClassOf("Register")) {
const CodeGenRegister *Reg =
CGP.getTargetInfo().getRegBank().getReg(Def);
AddMatcher(new EmitRegisterMatcher(Reg, N->getSimpleType(0)));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
if (Def->getName() == "zero_reg") {
AddMatcher(new EmitRegisterMatcher(nullptr, N->getSimpleType(0)));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
if (Def->getName() == "undef_tied_input") {
std::array<MVT::SimpleValueType, 1> ResultVTs = {{ N->getSimpleType(0) }};
std::array<unsigned, 0> InstOps;
auto IDOperandNo = NextRecordedOperandNo++;
AddMatcher(new EmitNodeMatcher("TargetOpcode::IMPLICIT_DEF",
ResultVTs, InstOps, false, false, false,
false, -1, IDOperandNo));
ResultOps.push_back(IDOperandNo);
return;
}
// Handle a reference to a register class. This is used
// in COPY_TO_SUBREG instructions.
if (Def->isSubClassOf("RegisterOperand"))
Def = Def->getValueAsDef("RegClass");
if (Def->isSubClassOf("RegisterClass")) {
std::string Value = getQualifiedName(Def) + "RegClassID";
AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
// Handle a subregister index. This is used for INSERT_SUBREG etc.
if (Def->isSubClassOf("SubRegIndex")) {
const CodeGenRegBank &RB = CGP.getTargetInfo().getRegBank();
// If we have more than 127 subreg indices the encoding can overflow
// 7 bit and we cannot use StringInteger.
if (RB.getSubRegIndices().size() > 127) {
const CodeGenSubRegIndex *I = RB.findSubRegIdx(Def);
assert(I && "Cannot find subreg index by name!");
if (I->EnumValue > 127) {
AddMatcher(new EmitIntegerMatcher(I->EnumValue, MVT::i32));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
}
std::string Value = getQualifiedName(Def);
AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32));
ResultOps.push_back(NextRecordedOperandNo++);
return;
}
}
errs() << "unhandled leaf node: \n";
N->dump();
}
static bool
mayInstNodeLoadOrStore(const TreePatternNode *N,
const CodeGenDAGPatterns &CGP) {
Record *Op = N->getOperator();
const CodeGenTarget &CGT = CGP.getTargetInfo();
CodeGenInstruction &II = CGT.getInstruction(Op);
return II.mayLoad || II.mayStore;
}
static unsigned
numNodesThatMayLoadOrStore(const TreePatternNode *N,
const CodeGenDAGPatterns &CGP) {
if (N->isLeaf())
return 0;
Record *OpRec = N->getOperator();
if (!OpRec->isSubClassOf("Instruction"))
return 0;
unsigned Count = 0;
if (mayInstNodeLoadOrStore(N, CGP))
++Count;
for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i)
Count += numNodesThatMayLoadOrStore(N->getChild(i), CGP);
return Count;
}
void MatcherGen::
EmitResultInstructionAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &OutputOps) {
Record *Op = N->getOperator();
const CodeGenTarget &CGT = CGP.getTargetInfo();
CodeGenInstruction &II = CGT.getInstruction(Op);
const DAGInstruction &Inst = CGP.getInstruction(Op);
bool isRoot = N == Pattern.getDstPattern();
// TreeHasOutGlue - True if this tree has glue.
bool TreeHasInGlue = false, TreeHasOutGlue = false;
if (isRoot) {
const TreePatternNode *SrcPat = Pattern.getSrcPattern();
TreeHasInGlue = SrcPat->TreeHasProperty(SDNPOptInGlue, CGP) ||
SrcPat->TreeHasProperty(SDNPInGlue, CGP);
// FIXME2: this is checking the entire pattern, not just the node in
// question, doing this just for the root seems like a total hack.
TreeHasOutGlue = SrcPat->TreeHasProperty(SDNPOutGlue, CGP);
}
// NumResults - This is the number of results produced by the instruction in
// the "outs" list.
unsigned NumResults = Inst.getNumResults();
// Number of operands we know the output instruction must have. If it is
// variadic, we could have more operands.
unsigned NumFixedOperands = II.Operands.size();
SmallVector<unsigned, 8> InstOps;
// Loop over all of the fixed operands of the instruction pattern, emitting
// code to fill them all in. The node 'N' usually has number children equal to
// the number of input operands of the instruction. However, in cases where
// there are predicate operands for an instruction, we need to fill in the
// 'execute always' values. Match up the node operands to the instruction
// operands to do this.
unsigned ChildNo = 0;
// Similarly to the code in TreePatternNode::ApplyTypeConstraints, count the
// number of operands at the end of the list which have default values.
// Those can come from the pattern if it provides enough arguments, or be
// filled in with the default if the pattern hasn't provided them. But any
// operand with a default value _before_ the last mandatory one will be
// filled in with their defaults unconditionally.
unsigned NonOverridableOperands = NumFixedOperands;
while (NonOverridableOperands > NumResults &&
CGP.operandHasDefault(II.Operands[NonOverridableOperands-1].Rec))
--NonOverridableOperands;
for (unsigned InstOpNo = NumResults, e = NumFixedOperands;
InstOpNo != e; ++InstOpNo) {
// Determine what to emit for this operand.
Record *OperandNode = II.Operands[InstOpNo].Rec;
if (CGP.operandHasDefault(OperandNode) &&
(InstOpNo < NonOverridableOperands || ChildNo >= N->getNumChildren())) {
// This is a predicate or optional def operand which the pattern has not
// overridden, or which we aren't letting it override; emit the 'default
// ops' operands.
const DAGDefaultOperand &DefaultOp
= CGP.getDefaultOperand(OperandNode);
for (unsigned i = 0, e = DefaultOp.DefaultOps.size(); i != e; ++i)
EmitResultOperand(DefaultOp.DefaultOps[i].get(), InstOps);
continue;
}
// Otherwise this is a normal operand or a predicate operand without
// 'execute always'; emit it.
// For operands with multiple sub-operands we may need to emit
// multiple child patterns to cover them all. However, ComplexPattern
// children may themselves emit multiple MI operands.
unsigned NumSubOps = 1;
if (OperandNode->isSubClassOf("Operand")) {
DagInit *MIOpInfo = OperandNode->getValueAsDag("MIOperandInfo");
if (unsigned NumArgs = MIOpInfo->getNumArgs())
NumSubOps = NumArgs;
}
unsigned FinalNumOps = InstOps.size() + NumSubOps;
while (InstOps.size() < FinalNumOps) {
const TreePatternNode *Child = N->getChild(ChildNo);
unsigned BeforeAddingNumOps = InstOps.size();
EmitResultOperand(Child, InstOps);
assert(InstOps.size() > BeforeAddingNumOps && "Didn't add any operands");
// If the operand is an instruction and it produced multiple results, just
// take the first one.
if (!Child->isLeaf() && Child->getOperator()->isSubClassOf("Instruction"))
InstOps.resize(BeforeAddingNumOps+1);
++ChildNo;
}
}
// If this is a variadic output instruction (i.e. REG_SEQUENCE), we can't
// expand suboperands, use default operands, or other features determined from
// the CodeGenInstruction after the fixed operands, which were handled
// above. Emit the remaining instructions implicitly added by the use for
// variable_ops.
if (II.Operands.isVariadic) {
for (unsigned I = ChildNo, E = N->getNumChildren(); I < E; ++I)
EmitResultOperand(N->getChild(I), InstOps);
}
// If this node has input glue or explicitly specified input physregs, we
// need to add chained and glued copyfromreg nodes and materialize the glue
// input.
if (isRoot && !PhysRegInputs.empty()) {
// Emit all of the CopyToReg nodes for the input physical registers. These
// occur in patterns like (mul:i8 AL:i8, GR8:i8:$src).
for (unsigned i = 0, e = PhysRegInputs.size(); i != e; ++i) {
const CodeGenRegister *Reg =
CGP.getTargetInfo().getRegBank().getReg(PhysRegInputs[i].first);
AddMatcher(new EmitCopyToRegMatcher(PhysRegInputs[i].second,
Reg));
}
// Even if the node has no other glue inputs, the resultant node must be
// glued to the CopyFromReg nodes we just generated.
TreeHasInGlue = true;
}
// Result order: node results, chain, glue
// Determine the result types.
SmallVector<MVT::SimpleValueType, 4> ResultVTs;
for (unsigned i = 0, e = N->getNumTypes(); i != e; ++i)
ResultVTs.push_back(N->getSimpleType(i));
// If this is the root instruction of a pattern that has physical registers in
// its result pattern, add output VTs for them. For example, X86 has:
// (set AL, (mul ...))
// This also handles implicit results like:
// (implicit EFLAGS)
if (isRoot && !Pattern.getDstRegs().empty()) {
// If the root came from an implicit def in the instruction handling stuff,
// don't re-add it.
Record *HandledReg = nullptr;
if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other)
HandledReg = II.ImplicitDefs[0];
for (Record *Reg : Pattern.getDstRegs()) {
if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue;
ResultVTs.push_back(getRegisterValueType(Reg, CGT));
}
}
// If this is the root of the pattern and the pattern we're matching includes
// a node that is variadic, mark the generated node as variadic so that it
// gets the excess operands from the input DAG.
int NumFixedArityOperands = -1;
if (isRoot &&
Pattern.getSrcPattern()->NodeHasProperty(SDNPVariadic, CGP))
NumFixedArityOperands = Pattern.getSrcPattern()->getNumChildren();
// If this is the root node and multiple matched nodes in the input pattern
// have MemRefs in them, have the interpreter collect them and plop them onto
// this node. If there is just one node with MemRefs, leave them on that node
// even if it is not the root.
//
// FIXME3: This is actively incorrect for result patterns with multiple
// memory-referencing instructions.
bool PatternHasMemOperands =
Pattern.getSrcPattern()->TreeHasProperty(SDNPMemOperand, CGP);
bool NodeHasMemRefs = false;
if (PatternHasMemOperands) {
unsigned NumNodesThatLoadOrStore =
numNodesThatMayLoadOrStore(Pattern.getDstPattern(), CGP);
bool NodeIsUniqueLoadOrStore = mayInstNodeLoadOrStore(N, CGP) &&
NumNodesThatLoadOrStore == 1;
NodeHasMemRefs =
NodeIsUniqueLoadOrStore || (isRoot && (mayInstNodeLoadOrStore(N, CGP) ||
NumNodesThatLoadOrStore != 1));
}
// Determine whether we need to attach a chain to this node.
bool NodeHasChain = false;
if (Pattern.getSrcPattern()->TreeHasProperty(SDNPHasChain, CGP)) {
// For some instructions, we were able to infer from the pattern whether
// they should have a chain. Otherwise, attach the chain to the root.
//
// FIXME2: This is extremely dubious for several reasons, not the least of
// which it gives special status to instructions with patterns that Pat<>
// nodes can't duplicate.
if (II.hasChain_Inferred)
NodeHasChain = II.hasChain;
else
NodeHasChain = isRoot;
// Instructions which load and store from memory should have a chain,
// regardless of whether they happen to have a pattern saying so.
if (II.hasCtrlDep || II.mayLoad || II.mayStore || II.canFoldAsLoad ||
II.hasSideEffects)
NodeHasChain = true;
}
assert((!ResultVTs.empty() || TreeHasOutGlue || NodeHasChain) &&
"Node has no result");
AddMatcher(new EmitNodeMatcher(II.Namespace.str()+"::"+II.TheDef->getName().str(),
ResultVTs, InstOps,
NodeHasChain, TreeHasInGlue, TreeHasOutGlue,
NodeHasMemRefs, NumFixedArityOperands,
NextRecordedOperandNo));
// The non-chain and non-glue results of the newly emitted node get recorded.
for (unsigned i = 0, e = ResultVTs.size(); i != e; ++i) {
if (ResultVTs[i] == MVT::Other || ResultVTs[i] == MVT::Glue) break;
OutputOps.push_back(NextRecordedOperandNo++);
}
}
void MatcherGen::
EmitResultSDNodeXFormAsOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps) {
assert(N->getOperator()->isSubClassOf("SDNodeXForm") && "Not SDNodeXForm?");
// Emit the operand.
SmallVector<unsigned, 8> InputOps;
// FIXME2: Could easily generalize this to support multiple inputs and outputs
// to the SDNodeXForm. For now we just support one input and one output like
// the old instruction selector.
assert(N->getNumChildren() == 1);
EmitResultOperand(N->getChild(0), InputOps);
// The input currently must have produced exactly one result.
assert(InputOps.size() == 1 && "Unexpected input to SDNodeXForm");
AddMatcher(new EmitNodeXFormMatcher(InputOps[0], N->getOperator()));
ResultOps.push_back(NextRecordedOperandNo++);
}
void MatcherGen::EmitResultOperand(const TreePatternNode *N,
SmallVectorImpl<unsigned> &ResultOps) {
// This is something selected from the pattern we matched.
if (!N->getName().empty())
return EmitResultOfNamedOperand(N, ResultOps);
if (N->isLeaf())
return EmitResultLeafAsOperand(N, ResultOps);
Record *OpRec = N->getOperator();
if (OpRec->isSubClassOf("Instruction"))
return EmitResultInstructionAsOperand(N, ResultOps);
if (OpRec->isSubClassOf("SDNodeXForm"))
return EmitResultSDNodeXFormAsOperand(N, ResultOps);
errs() << "Unknown result node to emit code for: " << *N << '\n';
PrintFatalError("Unknown node in result pattern!");
}
void MatcherGen::EmitResultCode() {
// Patterns that match nodes with (potentially multiple) chain inputs have to
// merge them together into a token factor. This informs the generated code
// what all the chained nodes are.
if (!MatchedChainNodes.empty())
AddMatcher(new EmitMergeInputChainsMatcher(MatchedChainNodes));
// Codegen the root of the result pattern, capturing the resulting values.
SmallVector<unsigned, 8> Ops;
EmitResultOperand(Pattern.getDstPattern(), Ops);
// At this point, we have however many values the result pattern produces.
// However, the input pattern might not need all of these. If there are
// excess values at the end (such as implicit defs of condition codes etc)
// just lop them off. This doesn't need to worry about glue or chains, just
// explicit results.
//
unsigned NumSrcResults = Pattern.getSrcPattern()->getNumTypes();
// If the pattern also has (implicit) results, count them as well.
if (!Pattern.getDstRegs().empty()) {
// If the root came from an implicit def in the instruction handling stuff,
// don't re-add it.
Record *HandledReg = nullptr;
const TreePatternNode *DstPat = Pattern.getDstPattern();
if (!DstPat->isLeaf() &&DstPat->getOperator()->isSubClassOf("Instruction")){
const CodeGenTarget &CGT = CGP.getTargetInfo();
CodeGenInstruction &II = CGT.getInstruction(DstPat->getOperator());
if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other)
HandledReg = II.ImplicitDefs[0];
}
for (Record *Reg : Pattern.getDstRegs()) {
if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue;
++NumSrcResults;
}
}
SmallVector<unsigned, 8> Results(Ops);
// Apply result permutation.
for (unsigned ResNo = 0; ResNo < Pattern.getDstPattern()->getNumResults();
++ResNo) {
Results[ResNo] = Ops[Pattern.getDstPattern()->getResultIndex(ResNo)];
}
Results.resize(NumSrcResults);
AddMatcher(new CompleteMatchMatcher(Results, Pattern));
}
/// ConvertPatternToMatcher - Create the matcher for the specified pattern with
/// the specified variant. If the variant number is invalid, this returns null.
Matcher *llvm::ConvertPatternToMatcher(const PatternToMatch &Pattern,
unsigned Variant,
const CodeGenDAGPatterns &CGP) {
MatcherGen Gen(Pattern, CGP);
// Generate the code for the matcher.
if (Gen.EmitMatcherCode(Variant))
return nullptr;
// FIXME2: Kill extra MoveParent commands at the end of the matcher sequence.
// FIXME2: Split result code out to another table, and make the matcher end
// with an "Emit <index>" command. This allows result generation stuff to be
// shared and factored?
// If the match succeeds, then we generate Pattern.
Gen.EmitResultCode();
// Unconditional match.
return Gen.GetMatcher();
}
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