[Mlir-commits] [mlir] 3b00f44 - [mlir][sparse] Marking off todos and updating commentary

[wren romano]

Author: wren romano
Date: 2023-07-31T14:35:39-07:00
New Revision: 3b00f4481101c2ab071736d052482e692c6ebb56

URL: https://github.com/llvm/llvm-project/commit/3b00f4481101c2ab071736d052482e692c6ebb56
DIFF: https://github.com/llvm/llvm-project/commit/3b00f4481101c2ab071736d052482e692c6ebb56.diff

LOG: [mlir][sparse] Marking off todos and updating commentary

Depends On D155999

Reviewed By: Peiming

Differential Revision: https://reviews.llvm.org/D156001

Added: 
    

Modified: 
    mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.cpp
    mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.h
    mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
    mlir/lib/Dialect/SparseTensor/IR/Detail/Var.h

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.cpp b/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.cpp
index ca26a83dcd0cdd..3de88aa085635b 100644
--- a/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.cpp
+++ b/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.cpp
@@ -150,8 +150,6 @@ void DimLvlExpr::printAffineExprInternal(
     rhs.printStrong(os);
   } else {
     // Combination of all the special rules for addition/subtraction.
-    // TODO(wrengr): despite being succinct, this is prolly too confusing for
-    // readers.
     lhs.printWeak(os);
     const auto rx = matchNeg(rhs);
     os << (rx ? " - " : " + ");
@@ -180,8 +178,9 @@ DimSpec::DimSpec(DimVar var, DimExpr expr, SparseTensorDimSliceAttr slice)
     : var(var), expr(expr), slice(slice) {}
 
 bool DimSpec::isValid(Ranks const &ranks) const {
-  return ranks.isValid(var) && ranks.isValid(expr);
-  // TODO(wrengr): is there anything in `slice` that needs validation?
+  // Nothing in `slice` needs additional validation.
+  // We explicitly consider null-expr to be vacuously valid.
+  return ranks.isValid(var) && (!expr || ranks.isValid(expr));
 }
 
 bool DimSpec::isFunctionOf(VarSet const &vars) const {
@@ -220,8 +219,8 @@ LvlSpec::LvlSpec(LvlVar var, LvlExpr expr, DimLevelType type)
 }
 
 bool LvlSpec::isValid(Ranks const &ranks) const {
+  // Nothing in `type` needs additional validation.
   return ranks.isValid(var) && ranks.isValid(expr);
-  // TODO(wrengr): is there anything in `type` that needs validation?
 }
 
 bool LvlSpec::isFunctionOf(VarSet const &vars) const {

diff  --git a/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.h b/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.h
index 9278d7c8d33ff9..a58ddcd4677414 100644
--- a/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.h
+++ b/mlir/lib/Dialect/SparseTensor/IR/Detail/DimLvlMap.h
@@ -220,8 +220,10 @@ class DimSpec final {
   void setElideExpr(bool b) { elideExpr = b; }
   constexpr SparseTensorDimSliceAttr getSlice() const { return slice; }
 
-  /// Checks whether the variables bound/used by this spec are valid
-  /// with respect to the given ranks.
+  /// Checks whether the variables bound/used by this spec are valid with
+  /// respect to the given ranks.  Note that null `DimExpr` is considered
+  /// to be vacuously valid, and therefore calling `setExpr` invalidates
+  /// the result of this predicate.
   bool isValid(Ranks const &ranks) const;
 
   // TODO(wrengr): Use it or loose it.

diff  --git a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
index a30058d512d44f..7e848d325fb743 100644
--- a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
+++ b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.cpp
@@ -33,13 +33,10 @@ void Var::dump() const {
 //===----------------------------------------------------------------------===//
 
 bool Ranks::isValid(DimLvlExpr expr) const {
-  // FIXME(wrengr): we have cases without affine expr at an early point
-  if (!expr.getAffineExpr())
-    return true;
-  // Each `DimLvlExpr` only allows one kind of non-symbol variable.
+  assert(expr);
+  // Compute the maximum identifiers for symbol-vars and dim/lvl-vars
+  // (each `DimLvlExpr` only allows one kind of non-symbol variable).
   int64_t maxSym = -1, maxVar = -1;
-  // TODO(wrengr): If we run into ASan issues, that may be due to the
-  // "`{{...}}`" syntax; so we may want to try using local-variables instead.
   mlir::getMaxDimAndSymbol<ArrayRef<AffineExpr>>({{expr.getAffineExpr()}},
                                                  maxVar, maxSym);
   // TODO(wrengr): We may want to add a call to `LLVM_DEBUG` like

diff  --git a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.h b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.h
index 313972b3ca79b6..cf5bc6d753de4f 100644
--- a/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.h
+++ b/mlir/lib/Dialect/SparseTensor/IR/Detail/Var.h
@@ -179,7 +179,10 @@ class Var {
 public:
   constexpr Var(VarKind vk, Num n) : impl(Impl(vk, n)) {}
   Var(AffineSymbolExpr sym) : Var(VarKind::Symbol, sym.getPosition()) {}
-  Var(VarKind vk, AffineDimExpr var) : Var(vk, var.getPosition()) {}
+  // TODO(wrengr): Should make the first argument an `ExprKind` instead...?
+  Var(VarKind vk, AffineDimExpr var) : Var(vk, var.getPosition()) {
+    assert(vk != VarKind::Symbol);
+  }
 
   constexpr bool operator==(Var other) const { return impl == other.impl; }
   constexpr bool operator!=(Var other) const { return !(*this == other); }
@@ -345,13 +348,8 @@ class VarInfo final {
   enum class ID : unsigned {};
 
 private:
-  // FUTURE_CL(wrengr): We could use the high-bit of `Var::Impl` to
-  // store the `std::optional` bit, therefore allowing us to bitbash the
-  // `num` and `kind` fields together.
-  //
   StringRef name;              // The bare-id used in the MLIR source.
   llvm::SMLoc loc;             // The location of the first occurence.
-                               // TODO(wrengr): See the above `LocatedVar` note.
   ID id;                       // The unique `VarInfo`-identifier.
   std::optional<Var::Num> num; // The unique `Var`-identifier (if resolved).
   VarKind kind;                // The kind of variable.