138 changes: 129 additions & 9 deletions llvm/utils/TableGen/GlobalISelEmitter.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -555,6 +555,9 @@ class RuleMatcher {
/// ID for the next output instruction allocated with allocateOutputInsnID()
unsigned NextOutputInsnID;

/// ID for the next temporary register ID allocated with allocateTempRegID()
unsigned NextTempRegID;

std::vector<Record *> RequiredFeatures;

ArrayRef<SMLoc> SrcLoc;
Expand All @@ -570,7 +573,7 @@ class RuleMatcher {
RuleMatcher(ArrayRef<SMLoc> SrcLoc)
: Matchers(), Actions(), InsnVariableIDs(), MutatableInsns(),
DefinedOperands(), NextInsnVarID(0), NextOutputInsnID(0),
SrcLoc(SrcLoc), ComplexSubOperands() {}
NextTempRegID(0), SrcLoc(SrcLoc), ComplexSubOperands() {}
RuleMatcher(RuleMatcher &&Other) = default;
RuleMatcher &operator=(RuleMatcher &&Other) = default;

Expand Down Expand Up @@ -658,6 +661,7 @@ class RuleMatcher {
InstructionMatcher &insnmatcher_front() const { return *Matchers.front(); }

unsigned allocateOutputInsnID() { return NextOutputInsnID++; }
unsigned allocateTempRegID() { return NextTempRegID++; }
};

using action_iterator = RuleMatcher::action_iterator;
Expand Down Expand Up @@ -1476,6 +1480,7 @@ class OperandRenderer {
OR_CopyFConstantAsFPImm,
OR_Imm,
OR_Register,
OR_TempRegister,
OR_ComplexPattern
};

Expand Down Expand Up @@ -1692,6 +1697,37 @@ class AddRegisterRenderer : public OperandRenderer {
}
};

/// Adds a specific temporary virtual register to the instruction being built.
/// This is used to chain instructions together when emitting multiple
/// instructions.
class TempRegRenderer : public OperandRenderer {
protected:
unsigned InsnID;
unsigned TempRegID;
bool IsDef;

public:
TempRegRenderer(unsigned InsnID, unsigned TempRegID, bool IsDef = false)
: OperandRenderer(OR_Register), InsnID(InsnID), TempRegID(TempRegID),
IsDef(IsDef) {}

static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_TempRegister;
}

void emitRenderOpcodes(MatchTable &Table, RuleMatcher &Rule) const override {
Table << MatchTable::Opcode("GIR_AddTempRegister")
<< MatchTable::Comment("InsnID") << MatchTable::IntValue(InsnID)
<< MatchTable::Comment("TempRegID") << MatchTable::IntValue(TempRegID)
<< MatchTable::Comment("TempRegFlags");
if (IsDef)
Table << MatchTable::NamedValue("RegState::Define");
else
Table << MatchTable::IntValue(0);
Table << MatchTable::LineBreak;
}
};

/// Adds a specific immediate to the instruction being built.
class ImmRenderer : public OperandRenderer {
protected:
Expand Down Expand Up @@ -1906,9 +1942,13 @@ class BuildMIAction : public MatchAction {
<< MatchTable::LineBreak;
}

Table << MatchTable::Opcode("GIR_EraseFromParent")
<< MatchTable::Comment("InsnID") << MatchTable::IntValue(0)
<< MatchTable::LineBreak;
// FIXME: This is a hack but it's sufficient for ISel. We'll need to do
// better for combines. Particularly when there are multiple match
// roots.
if (InsnID == 0)
Table << MatchTable::Opcode("GIR_EraseFromParent")
<< MatchTable::Comment("InsnID") << MatchTable::IntValue(InsnID)
<< MatchTable::LineBreak;
}
};

Expand Down Expand Up @@ -1948,6 +1988,26 @@ class ConstrainOperandToRegClassAction : public MatchAction {
}
};

/// Generates code to create a temporary register which can be used to chain
/// instructions together.
class MakeTempRegisterAction : public MatchAction {
private:
LLTCodeGen Ty;
unsigned TempRegID;

public:
MakeTempRegisterAction(const LLTCodeGen &Ty, unsigned TempRegID)
: Ty(Ty), TempRegID(TempRegID) {}

void emitActionOpcodes(MatchTable &Table, RuleMatcher &Rule) const override {
Table << MatchTable::Opcode("GIR_MakeTempReg")
<< MatchTable::Comment("TempRegID") << MatchTable::IntValue(TempRegID)
<< MatchTable::Comment("TypeID")
<< MatchTable::NamedValue(Ty.getCxxEnumValue())
<< MatchTable::LineBreak;
}
};

InstructionMatcher &RuleMatcher::addInstructionMatcher(StringRef SymbolicName) {
Matchers.emplace_back(new InstructionMatcher(*this, SymbolicName));
MutatableInsns.insert(Matchers.back().get());
Expand All @@ -1974,6 +2034,7 @@ Kind &RuleMatcher::addAction(Args &&... args) {
Actions.emplace_back(llvm::make_unique<Kind>(std::forward<Args>(args)...));
return *static_cast<Kind *>(Actions.back().get());
}

// Emplaces an action of the specified Kind before the given insertion point.
//
// Returns an iterator pointing at the newly created instruction.
Expand All @@ -1984,7 +2045,8 @@ Kind &RuleMatcher::addAction(Args &&... args) {
template <class Kind, class... Args>
action_iterator RuleMatcher::insertAction(action_iterator InsertPt,
Args &&... args) {
return Actions.insert(InsertPt, llvm::make_unique<Kind>(std::forward<Args>(args)...));
return Actions.emplace(InsertPt,
llvm::make_unique<Kind>(std::forward<Args>(args)...));
}

unsigned
Expand Down Expand Up @@ -2264,6 +2326,9 @@ class GlobalISelEmitter {
Expected<BuildMIAction &>
createAndImportInstructionRenderer(RuleMatcher &M,
const TreePatternNode *Dst);
Expected<action_iterator> createAndImportSubInstructionRenderer(
action_iterator InsertPt, RuleMatcher &M, const TreePatternNode *Dst,
unsigned TempReg);
Expected<action_iterator>
createInstructionRenderer(action_iterator InsertPt, RuleMatcher &M,
const TreePatternNode *Dst);
Expand All @@ -2275,7 +2340,7 @@ class GlobalISelEmitter {
Expected<action_iterator>
importExplicitUseRenderer(action_iterator InsertPt, RuleMatcher &Rule,
BuildMIAction &DstMIBuilder,
TreePatternNode *DstChild) const;
TreePatternNode *DstChild);
Error importDefaultOperandRenderers(BuildMIAction &DstMIBuilder,
DagInit *DefaultOps) const;
Error
Expand Down Expand Up @@ -2607,7 +2672,7 @@ Error GlobalISelEmitter::importChildMatcher(RuleMatcher &Rule,

Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderer(
action_iterator InsertPt, RuleMatcher &Rule, BuildMIAction &DstMIBuilder,
TreePatternNode *DstChild) const {
TreePatternNode *DstChild) {
if (DstChild->getTransformFn() != nullptr) {
return failedImport("Dst pattern child has transform fn " +
DstChild->getTransformFn()->getName());
Expand Down Expand Up @@ -2645,6 +2710,30 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderer(
return InsertPt;
}

if (DstChild->getOperator()->isSubClassOf("Instruction")) {
ArrayRef<TypeSetByHwMode> ChildTypes = DstChild->getExtTypes();
if (ChildTypes.size() != 1)
return failedImport("Dst pattern child has multiple results");

Optional<LLTCodeGen> OpTyOrNone = None;
if (ChildTypes.front().isMachineValueType())
OpTyOrNone =
MVTToLLT(ChildTypes.front().getMachineValueType().SimpleTy);
if (!OpTyOrNone)
return failedImport("Dst operand has an unsupported type");

unsigned TempRegID = Rule.allocateTempRegID();
InsertPt = Rule.insertAction<MakeTempRegisterAction>(
InsertPt, OpTyOrNone.getValue(), TempRegID);
DstMIBuilder.addRenderer<TempRegRenderer>(TempRegID);

auto InsertPtOrError = createAndImportSubInstructionRenderer(
++InsertPt, Rule, DstChild, TempRegID);
if (auto Error = InsertPtOrError.takeError())
return std::move(Error);
return InsertPtOrError.get();
}

return failedImport("Dst pattern child isn't a leaf node or an MBB" + llvm::to_string(*DstChild));
}

Expand Down Expand Up @@ -2723,6 +2812,31 @@ Expected<BuildMIAction &> GlobalISelEmitter::createAndImportInstructionRenderer(
return DstMIBuilder;
}

Expected<action_iterator>
GlobalISelEmitter::createAndImportSubInstructionRenderer(
action_iterator InsertPt, RuleMatcher &M, const TreePatternNode *Dst,
unsigned TempRegID) {
auto InsertPtOrError = createInstructionRenderer(InsertPt, M, Dst);

// TODO: Assert there's exactly one result.

if (auto Error = InsertPtOrError.takeError())
return std::move(Error);
InsertPt = InsertPtOrError.get();

BuildMIAction &DstMIBuilder =
*static_cast<BuildMIAction *>(InsertPtOrError.get()->get());

// Assign the result to TempReg.
DstMIBuilder.addRenderer<TempRegRenderer>(TempRegID, true);

InsertPtOrError = importExplicitUseRenderers(InsertPt, M, DstMIBuilder, Dst);
if (auto Error = InsertPtOrError.takeError())
return std::move(Error);

return InsertPtOrError.get();
}

Expected<action_iterator> GlobalISelEmitter::createInstructionRenderer(
action_iterator InsertPt, RuleMatcher &M, const TreePatternNode *Dst) {
Record *DstOp = Dst->getOperator();
Expand All @@ -2740,6 +2854,8 @@ Expected<action_iterator> GlobalISelEmitter::createInstructionRenderer(
DstI = &Target.getInstruction(RK.getDef("COPY"));
else if (DstI->TheDef->getName() == "EXTRACT_SUBREG")
DstI = &Target.getInstruction(RK.getDef("COPY"));
else if (DstI->TheDef->getName() == "REG_SEQUENCE")
return failedImport("Unable to emit REG_SEQUENCE");

return M.insertAction<BuildMIAction>(InsertPt, M.allocateOutputInsnID(),
DstI);
Expand Down Expand Up @@ -2767,8 +2883,12 @@ Expected<action_iterator> GlobalISelEmitter::importExplicitUseRenderers(

if (DefInit *SubRegInit =
dyn_cast<DefInit>(Dst->getChild(1)->getLeafValue())) {
CodeGenRegisterClass *RC = CGRegs.getRegClass(
getInitValueAsRegClass(Dst->getChild(0)->getLeafValue()));
Record *RCDef = getInitValueAsRegClass(Dst->getChild(0)->getLeafValue());
if (!RCDef)
return failedImport("EXTRACT_SUBREG child #0 could not "
"be coerced to a register class");

CodeGenRegisterClass *RC = CGRegs.getRegClass(RCDef);
CodeGenSubRegIndex *SubIdx = CGRegs.getSubRegIdx(SubRegInit->getDef());

const auto &SrcRCDstRCPair =
Expand Down