[mlir] Add predicates to tablegen-defined properties (#120176)

Give the properties from tablegen a `predicate` field that holds the
predicate that the property needs to satisfy, if one exists, and hook
that field up to verifier generation.

Author: krzysz00

mlir/include/mlir/IR/Constraints.td

@@ -93,6 +93,12 @@ class Or<list<Pred> children> : CombinedPred<PredCombinerOr, children>;
 // A predicate that holds if its child does not.
 class Neg<Pred child> : CombinedPred<PredCombinerNot, [child]>;
 
+// A predicate that is always true.
+defvar TruePred = And<[]>;
+
+// A predicate that is always false.
+defvar False = Or<[]>;
+
 // A predicate that substitutes "pat" with "repl" in predicate calls of the
 // leaves of the predicate tree (i.e., not CombinedPred).
 //

mlir/include/mlir/IR/Properties.td

@@ -13,6 +13,8 @@
 #ifndef PROPERTIES
 #define PROPERTIES
 
+include "mlir/IR/Constraints.td"
+
 // Base class for defining properties.
 class Property<string storageTypeParam = "", string desc = ""> {
   // User-readable one line summary used in error reporting messages. If empty,
@@ -63,6 +65,13 @@ class Property<string storageTypeParam = "", string desc = ""> {
     return convertFromAttribute($_storage, $_attr, $_diag);
   }];
 
+  // The verification predicate for this property. Defaults to the true predicate,
+  // since properties are always their expected type.
+  // Within the predicate, `$_self` is an instance of the **interface**
+  // type of the property. Setting this field to ? will also result in a
+  // true predicate but is not recommended, as it breaks composability.
+  Pred predicate = TruePred;
+
   // The call expression to hash the property.
   //
   // Format:
@@ -150,8 +159,8 @@ class Property<string storageTypeParam = "", string desc = ""> {
       return ::mlir::failure();
   }];
 
-  // Base definition for the property. (Will be) used for `OptionalProperty` and
-  // such cases, analogously to `baseAttr`.
+  // Base definition for the property. Used to look through `OptionalProperty`
+  // for some format generation, as with the `baseAttr` field on attributes.
   Property baseProperty = ?;
 
   // Default value for the property within its storage. This should be an expression
@@ -224,8 +233,7 @@ def I64Property : IntProperty<"int64_t">;
 
 class EnumProperty<string storageTypeParam, string desc = "", string default = ""> :
     Property<storageTypeParam, desc> {
-  // TODO: take advantage of EnumAttrInfo and the like to make this share nice
-  // parsing code with EnumAttr.
+  // TODO:  implement predicate for enum validity.
   let writeToMlirBytecode = [{
     $_writer.writeVarInt(static_cast<uint64_t>($_storage));
   }];
@@ -330,6 +338,59 @@ def UnitProperty : Property<"bool", "unit property"> {
   }];
 }
 
+//===----------------------------------------------------------------------===//
+// Property field overwrites
+
+/// Class for giving a property a default value.
+/// This doesn't change anything about the property other than giving it a default
+/// which can be used by ODS to elide printing.
+class DefaultValuedProperty<Property p, string default = "", string storageDefault = ""> : Property<p.storageType, p.summary> {
+  let defaultValue = default;
+  let storageTypeValueOverride = storageDefault;
+  let baseProperty = p;
+  // Keep up to date with `Property` above.
+  let summary = p.summary;
+  let description = p.description;
+  let storageType = p.storageType;
+  let interfaceType = p.interfaceType;
+  let convertFromStorage = p.convertFromStorage;
+  let assignToStorage = p.assignToStorage;
+  let convertToAttribute = p.convertToAttribute;
+  let convertFromAttribute = p.convertFromAttribute;
+  let predicate = p.predicate;
+  let hashProperty = p.hashProperty;
+  let parser = p.parser;
+  let optionalParser = p.optionalParser;
+  let printer = p.printer;
+  let readFromMlirBytecode = p.readFromMlirBytecode;
+  let writeToMlirBytecode = p.writeToMlirBytecode;
+}
+
+/// Apply the predicate `pred` to the property `p`, ANDing it with any
+/// predicates it may already have. If `newSummary` is provided, replace the
+/// summary of `p` with `newSummary`.
+class ConfinedProperty<Property p, Pred pred, string newSummary = "">
+    : Property<p.storageType, !if(!empty(newSummary), p.summary, newSummary)> {
+  let predicate = !if(!ne(p.predicate, TruePred), And<[p.predicate, pred]>, pred);
+  let baseProperty = p;
+  // Keep up to date with `Property` above.
+  let description = p.description;
+  let storageType = p.storageType;
+  let interfaceType = p.interfaceType;
+  let convertFromStorage = p.convertFromStorage;
+  let assignToStorage = p.assignToStorage;
+  let convertToAttribute = p.convertToAttribute;
+  let convertFromAttribute = p.convertFromAttribute;
+  let hashProperty = p.hashProperty;
+  let parser = p.parser;
+  let optionalParser = p.optionalParser;
+  let printer = p.printer;
+  let readFromMlirBytecode = p.readFromMlirBytecode;
+  let writeToMlirBytecode = p.writeToMlirBytecode;
+  let defaultValue = p.defaultValue;
+  let storageTypeValueOverride = p.storageTypeValueOverride;
+}
+
 //===----------------------------------------------------------------------===//
 // Primitive property combinators
 
@@ -342,14 +403,35 @@ class _makePropStorage<Property prop, string name> {
         true : "") # ";";
 }
 
+/// Construct a `Pred`icate `ret` that wraps the predicate of the underlying
+/// property `childProp` with:
+///
+///   [](childProp.storageType& s) {
+///     return [](childProp.interfaceType i) {
+///       return leafSubst(childProp.predicate, "$_self" to "i");
+///     }(childProp.convertFromStorage(s))
+///   }
+///
+/// and then appends `prefix` and `suffix`.
+class _makeStorageWrapperPred<Property wrappedProp> {
+  Pred ret =
+    Concat<
+      "[](" # "const " # wrappedProp.storageType
+        # "& baseStore) -> bool { return []("
+        # wrappedProp.interfaceType # " baseIface) -> bool { return (",
+      SubstLeaves<"$_self", "baseIface", wrappedProp.predicate>,
+      "); }(" # !subst("$_storage", "baseStore", wrappedProp.convertFromStorage)
+        # "); }">;
+}
+
 /// The generic class for arrays of some other property, which is stored as a
 /// `SmallVector` of that property. This uses an `ArrayAttr` as its attribute form
 /// though subclasses can override this, as is the case with IntArrayAttr below.
 /// Those wishing to use a non-default number of SmallVector elements should
 /// subclass `ArrayProperty`.
-class ArrayProperty<Property elem = Property<>, string desc = ""> :
-  Property<"::llvm::SmallVector<" # elem.storageType # ">", desc> {
-  let summary = "array of " # elem.summary;
+class ArrayProperty<Property elem = Property<>, string newSummary = ""> :
+  Property<"::llvm::SmallVector<" # elem.storageType # ">",
+    !if(!empty(newSummary), "array of " # elem.summary, newSummary)> {
   let interfaceType = "::llvm::ArrayRef<" # elem.storageType # ">";
   let convertFromStorage = "::llvm::ArrayRef<" # elem.storageType # ">{$_storage}";
   let assignToStorage = "$_storage.assign($_value.begin(), $_value.end())";
@@ -382,6 +464,10 @@ class ArrayProperty<Property elem = Property<>, string desc = ""> :
     return ::mlir::ArrayAttr::get($_ctxt, elems);
   }];
 
+  let predicate = !if(!eq(elem.predicate, TruePred),
+    TruePred,
+    Concat<"::llvm::all_of($_self, ", _makeStorageWrapperPred<elem>.ret, ")">);
+
   defvar theParserBegin = [{
     auto& storage = $_storage;
     auto parseElemFn = [&]() -> ::mlir::ParseResult {
@@ -463,8 +549,8 @@ class ArrayProperty<Property elem = Property<>, string desc = ""> :
     }]);
 }
 
-class IntArrayProperty<string storageTypeParam = "", string desc = ""> :
-    ArrayProperty<IntProperty<storageTypeParam, desc>> {
+class IntArrayProperty<Property elem, string newSummary=""> :
+    ArrayProperty<elem, newSummary> {
   // Bring back the trivial conversions we don't get in the general case.
   let convertFromAttribute = [{
     return convertFromAttribute($_storage, $_attr, $_diag);
@@ -474,30 +560,6 @@ class IntArrayProperty<string storageTypeParam = "", string desc = ""> :
   }];
 }
 
-/// Class for giving a property a default value.
-/// This doesn't change anything about the property other than giving it a default
-/// which can be used by ODS to elide printing.
-class DefaultValuedProperty<Property p, string default = "", string storageDefault = ""> : Property<p.storageType, p.summary> {
-  let defaultValue = default;
-  let storageTypeValueOverride = storageDefault;
-  let baseProperty = p;
-  // Keep up to date with `Property` above.
-  let summary = p.summary;
-  let description = p.description;
-  let storageType = p.storageType;
-  let interfaceType = p.interfaceType;
-  let convertFromStorage = p.convertFromStorage;
-  let assignToStorage = p.assignToStorage;
-  let convertToAttribute = p.convertToAttribute;
-  let convertFromAttribute = p.convertFromAttribute;
-  let hashProperty = p.hashProperty;
-  let parser = p.parser;
-  let optionalParser = p.optionalParser;
-  let printer = p.printer;
-  let readFromMlirBytecode = p.readFromMlirBytecode;
-  let writeToMlirBytecode = p.writeToMlirBytecode;
-}
-
 /// An optional property, stored as an std::optional<p.storageType>
 /// interfaced with as an std::optional<p.interfaceType>..
 /// The syntax is `none` (or empty string if elided) for an absent value or
@@ -575,6 +637,11 @@ class OptionalProperty<Property p, bit canDelegateParsing = 1>
     return ::mlir::ArrayAttr::get($_ctxt, {attr});
   }];
 
+  let predicate = !if(!ne(p.predicate, TruePred),
+    Or<[CPred<"!$_self.has_value()">,
+        SubstLeaves<"$_self", "(*($_self))", p.predicate>]>,
+    TruePred);
+
   defvar delegatedParserBegin = [{
     if (::mlir::succeeded($_parser.parseOptionalKeyword("none"))) {
       $_storage = std::nullopt;

mlir/include/mlir/TableGen/Property.h

@@ -27,6 +27,7 @@ namespace mlir {
 namespace tblgen {
 class Dialect;
 class Type;
+class Pred;
 
 // Wrapper class providing helper methods for accessing MLIR Property defined
 // in TableGen. This class should closely reflect what is defined as class
@@ -74,6 +75,10 @@ class Property {
     return convertFromAttributeCall;
   }
 
+  // Return the property's predicate. Properties that didn't come from
+  // tablegen (the hardcoded ones) have the null predicate.
+  Pred getPredicate() const;
+
   // Returns the method call which parses this property from textual MLIR.
   StringRef getParserCall() const { return parserCall; }
 

mlir/lib/TableGen/Predicate.cpp

@@ -235,6 +235,16 @@ propagateGroundTruth(PredNode *node,
     return node;
   }
 
+  if (node->kind == PredCombinerKind::And && node->children.empty()) {
+    node->kind = PredCombinerKind::True;
+    return node;
+  }
+
+  if (node->kind == PredCombinerKind::Or && node->children.empty()) {
+    node->kind = PredCombinerKind::False;
+    return node;
+  }
+
   // Otherwise, look at child nodes.
 
   // Move child nodes into some local variable so that they can be optimized

mlir/lib/TableGen/Property.cpp

@@ -14,6 +14,7 @@
 #include "mlir/TableGen/Property.h"
 #include "mlir/TableGen/Format.h"
 #include "mlir/TableGen/Operator.h"
+#include "mlir/TableGen/Predicate.h"
 #include "llvm/TableGen/Record.h"
 
 using namespace mlir;
@@ -68,8 +69,8 @@ Property::Property(StringRef summary, StringRef description,
                    StringRef writeToMlirBytecodeCall,
                    StringRef hashPropertyCall, StringRef defaultValue,
                    StringRef storageTypeValueOverride)
-    : summary(summary), description(description), storageType(storageType),
-      interfaceType(interfaceType),
+    : def(nullptr), summary(summary), description(description),
+      storageType(storageType), interfaceType(interfaceType),
       convertFromStorageCall(convertFromStorageCall),
       assignToStorageCall(assignToStorageCall),
       convertToAttributeCall(convertToAttributeCall),
@@ -91,6 +92,15 @@ StringRef Property::getPropertyDefName() const {
   return def->getName();
 }
 
+Pred Property::getPredicate() const {
+  if (!def)
+    return Pred();
+  const llvm::RecordVal *maybePred = def->getValue("predicate");
+  if (!maybePred || !maybePred->getValue())
+    return Pred();
+  return Pred(maybePred->getValue());
+}
+
 Property Property::getBaseProperty() const {
   if (const auto *defInit =
           llvm::dyn_cast<llvm::DefInit>(def->getValueInit("baseProperty"))) {