[globalisel][tablegen] Revise API for ComplexPattern operands to improve flexibility.
Summary:
Some targets need to be able to do more complex rendering than just adding an
operand or two to an instruction. For example, it may need to insert an
instruction to extract a subreg first, or it may need to perform an operation
on the operand.
In SelectionDAG, targets would create SDNode's to achieve the desired effect
during the complex pattern predicate. This worked because SelectionDAG had a
form of garbage collection that would take care of SDNode's that were created
but not used due to a later predicate rejecting a match. This doesn't translate
well to GlobalISel and the churn was wasteful.
The API changes in this patch enable GlobalISel to accomplish the same thing
without the waste. The API is now:
InstructionSelector::OptionalComplexRendererFn selectArithImmed(MachineOperand &Root) const;
where Root is the root of the match. The return value can be omitted to
indicate that the predicate failed to match, or a function with the signature
ComplexRendererFn can be returned. For example:
return OptionalComplexRendererFn(
[=](MachineInstrBuilder &MIB) { MIB.addImm(Immed).addImm(ShVal); });
adds two immediate operands to the rendered instruction. Immed and ShVal are
captured from the predicate function.
As an added bonus, this also reduces the amount of information we need to
provide to GIComplexOperandMatcher.
Depends on D31418
Reviewers: aditya_nandakumar, t.p.northover, qcolombet, rovka, ab, javed.absar
Reviewed By: ab
Subscribers: dberris, kristof.beyls, igorb, llvm-commits
Differential Revision: https://reviews.llvm.org/D31761
llvm-svn: 301079
diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index 488bf8d..b637114 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -91,52 +91,6 @@
};
class InstructionMatcher;
-class OperandPlaceholder {
-private:
- enum PlaceholderKind {
- OP_MatchReference,
- OP_Temporary,
- } Kind;
-
- struct MatchReferenceData {
- InstructionMatcher *InsnMatcher;
- StringRef InsnVarName;
- StringRef SymbolicName;
- };
-
- struct TemporaryData {
- unsigned OpIdx;
- };
-
- union {
- struct MatchReferenceData MatchReference;
- struct TemporaryData Temporary;
- };
-
- OperandPlaceholder(PlaceholderKind Kind) : Kind(Kind) {}
-
-public:
- ~OperandPlaceholder() {}
-
- static OperandPlaceholder
- CreateMatchReference(InstructionMatcher *InsnMatcher,
- StringRef InsnVarName, StringRef SymbolicName) {
- OperandPlaceholder Result(OP_MatchReference);
- Result.MatchReference.InsnMatcher = InsnMatcher;
- Result.MatchReference.InsnVarName = InsnVarName;
- Result.MatchReference.SymbolicName = SymbolicName;
- return Result;
- }
-
- static OperandPlaceholder CreateTemporary(unsigned OpIdx) {
- OperandPlaceholder Result(OP_Temporary);
- Result.Temporary.OpIdx = OpIdx;
- return Result;
- }
-
- void emitCxxValueExpr(raw_ostream &OS) const;
-};
-
/// Convert an MVT to an equivalent LLT if possible, or the invalid LLT() for
/// MVTs that don't map cleanly to an LLT (e.g., iPTR, *any, ...).
static Optional<LLTCodeGen> MVTToLLT(MVT::SimpleValueType SVT) {
@@ -256,7 +210,10 @@
/// Report the maximum number of temporary operands needed by the rule
/// matcher.
- unsigned countTemporaryOperands() const;
+ unsigned countRendererFns() const;
+
+ // FIXME: Remove this as soon as possible
+ InstructionMatcher &insnmatcher_front() const { return *Matchers.front(); }
};
template <class PredicateTy> class PredicateListMatcher {
@@ -361,7 +318,7 @@
/// Report the maximum number of temporary operands needed by the predicate
/// matcher.
- virtual unsigned countTemporaryOperands() const { return 0; }
+ virtual unsigned countRendererFns() const { return 0; }
};
/// Generates code to check that an operand is a particular LLT.
@@ -391,10 +348,6 @@
const OperandMatcher &Operand;
const Record &TheDef;
- unsigned getNumOperands() const {
- return TheDef.getValueAsDag("Operands")->getNumArgs();
- }
-
unsigned getAllocatedTemporariesBaseID() const;
public:
@@ -409,17 +362,13 @@
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
- OS << TheDef.getValueAsString("MatcherFn") << "(" << OperandExpr;
- for (unsigned I = 0; I < getNumOperands(); ++I) {
- OS << ", ";
- OperandPlaceholder::CreateTemporary(getAllocatedTemporariesBaseID() + I)
- .emitCxxValueExpr(OS);
- }
- OS << ")";
+ unsigned ID = getAllocatedTemporariesBaseID();
+ OS << "(Renderer" << ID << " = " << TheDef.getValueAsString("MatcherFn")
+ << "(" << OperandExpr << "))";
}
- unsigned countTemporaryOperands() const override {
- return getNumOperands();
+ unsigned countRendererFns() const override {
+ return 1;
}
};
@@ -488,7 +437,7 @@
/// The index of the first temporary variable allocated to this operand. The
/// number of allocated temporaries can be found with
- /// countTemporaryOperands().
+ /// countRendererFns().
unsigned AllocatedTemporariesBaseID;
public:
@@ -569,12 +518,12 @@
/// Report the maximum number of temporary operands needed by the operand
/// matcher.
- unsigned countTemporaryOperands() const {
+ unsigned countRendererFns() const {
return std::accumulate(
predicates().begin(), predicates().end(), 0,
[](unsigned A,
const std::unique_ptr<OperandPredicateMatcher> &Predicate) {
- return A + Predicate->countTemporaryOperands();
+ return A + Predicate->countRendererFns();
});
}
@@ -623,7 +572,7 @@
/// Report the maximum number of temporary operands needed by the predicate
/// matcher.
- virtual unsigned countTemporaryOperands() const { return 0; }
+ virtual unsigned countRendererFns() const { return 0; }
};
/// Generates code to check the opcode of an instruction.
@@ -780,17 +729,17 @@
/// Report the maximum number of temporary operands needed by the instruction
/// matcher.
- unsigned countTemporaryOperands() const {
+ unsigned countRendererFns() const {
return std::accumulate(predicates().begin(), predicates().end(), 0,
[](unsigned A,
const std::unique_ptr<InstructionPredicateMatcher>
&Predicate) {
- return A + Predicate->countTemporaryOperands();
+ return A + Predicate->countRendererFns();
}) +
std::accumulate(
Operands.begin(), Operands.end(), 0,
[](unsigned A, const std::unique_ptr<OperandMatcher> &Operand) {
- return A + Operand->countTemporaryOperands();
+ return A + Operand->countRendererFns();
});
}
};
@@ -845,18 +794,6 @@
};
//===- Actions ------------------------------------------------------------===//
-void OperandPlaceholder::emitCxxValueExpr(raw_ostream &OS) const {
- switch (Kind) {
- case OP_MatchReference:
- OS << MatchReference.InsnMatcher->getOperand(MatchReference.SymbolicName)
- .getOperandExpr(MatchReference.InsnVarName);
- break;
- case OP_Temporary:
- OS << "TempOp" << Temporary.OpIdx;
- break;
- }
-}
-
class OperandRenderer {
public:
enum RendererKind { OR_Copy, OR_Imm, OR_Register, OR_ComplexPattern };
@@ -942,31 +879,33 @@
}
};
+/// Adds operands by calling a renderer function supplied by the ComplexPattern
+/// matcher function.
class RenderComplexPatternOperand : public OperandRenderer {
private:
const Record &TheDef;
- std::vector<OperandPlaceholder> Sources;
+ /// The name of the operand.
+ const StringRef SymbolicName;
+ /// The renderer number. This must be unique within a rule since it's used to
+ /// identify a temporary variable to hold the renderer function.
+ unsigned RendererID;
unsigned getNumOperands() const {
return TheDef.getValueAsDag("Operands")->getNumArgs();
}
public:
- RenderComplexPatternOperand(const Record &TheDef,
- const ArrayRef<OperandPlaceholder> Sources)
- : OperandRenderer(OR_ComplexPattern), TheDef(TheDef), Sources(Sources) {}
+ RenderComplexPatternOperand(const Record &TheDef, StringRef SymbolicName,
+ unsigned RendererID)
+ : OperandRenderer(OR_ComplexPattern), TheDef(TheDef),
+ SymbolicName(SymbolicName), RendererID(RendererID) {}
static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_ComplexPattern;
}
void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const override {
- assert(Sources.size() == getNumOperands() && "Inconsistent number of operands");
- for (const auto &Source : Sources) {
- OS << "MIB.add(";
- Source.emitCxxValueExpr(OS);
- OS << ");\n";
- }
+ OS << "Renderer" << RendererID << "(MIB);\n";
}
};
@@ -1249,11 +1188,11 @@
return false;
}
-unsigned RuleMatcher::countTemporaryOperands() const {
+unsigned RuleMatcher::countRendererFns() const {
return std::accumulate(
Matchers.begin(), Matchers.end(), 0,
[](unsigned A, const std::unique_ptr<InstructionMatcher> &Matcher) {
- return A + Matcher->countTemporaryOperands();
+ return A + Matcher->countRendererFns();
});
}
@@ -1452,9 +1391,9 @@
return failedImport("SelectionDAG ComplexPattern (" +
ChildRec->getName() + ") not mapped to GlobalISel");
- const auto &Predicate = OM.addPredicate<ComplexPatternOperandMatcher>(
- OM, *ComplexPattern->second);
- TempOpIdx += Predicate.countTemporaryOperands();
+ OM.addPredicate<ComplexPatternOperandMatcher>(OM,
+ *ComplexPattern->second);
+ TempOpIdx++;
return Error::success();
}
@@ -1519,13 +1458,10 @@
return failedImport(
"SelectionDAG ComplexPattern not mapped to GlobalISel");
- SmallVector<OperandPlaceholder, 2> RenderedOperands;
const OperandMatcher &OM = InsnMatcher.getOperand(DstChild->getName());
- for (unsigned I = 0; I < OM.countTemporaryOperands(); ++I)
- RenderedOperands.push_back(OperandPlaceholder::CreateTemporary(
- OM.getAllocatedTemporariesBaseID() + I));
DstMIBuilder.addRenderer<RenderComplexPatternOperand>(
- *ComplexPattern->second, RenderedOperands);
+ *ComplexPattern->second, DstChild->getName(),
+ OM.getAllocatedTemporariesBaseID());
return Error::success();
}
@@ -1745,7 +1681,7 @@
unsigned MaxTemporaries = 0;
for (const auto &Rule : Rules)
- MaxTemporaries = std::max(MaxTemporaries, Rule.countTemporaryOperands());
+ MaxTemporaries = std::max(MaxTemporaries, Rule.countRendererFns());
OS << "#ifdef GET_GLOBALISEL_PREDICATE_BITSET\n"
<< "const unsigned MAX_SUBTARGET_PREDICATES = " << SubtargetFeatures.size()
@@ -1756,12 +1692,12 @@
OS << "#ifdef GET_GLOBALISEL_TEMPORARIES_DECL\n";
for (unsigned I = 0; I < MaxTemporaries; ++I)
- OS << " mutable MachineOperand TempOp" << I << ";\n";
+ OS << " mutable ComplexRendererFn Renderer" << I << ";\n";
OS << "#endif // ifdef GET_GLOBALISEL_TEMPORARIES_DECL\n\n";
OS << "#ifdef GET_GLOBALISEL_TEMPORARIES_INIT\n";
for (unsigned I = 0; I < MaxTemporaries; ++I)
- OS << ", TempOp" << I << "(MachineOperand::CreatePlaceholder())\n";
+ OS << ", Renderer" << I << "(nullptr)\n";
OS << "#endif // ifdef GET_GLOBALISEL_TEMPORARIES_INIT\n\n";
OS << "#ifdef GET_GLOBALISEL_IMPL\n";