[MLIR] Rename Shape dialect's `join` to `meet`.

For the type lattice, we (now) use the "less specialized or equal" partial
order, leading to the bottom representing the empty set, and the top
representing any type.

This naming is more in line with the generally used conventions, where the top
of the lattice is the full set, and the bottom of the lattice is the empty set.
A typical example is the powerset of a finite set: generally, meet would be the
intersection, and join would be the union.

```
top:  {a,b,c}
     /   |   \
 {a,b} {a,c} {b,c}
   |  X     X  |
   {a} { b } {c}
      \  |  /
bottom: { }
```

This is in line with the examined lattice representations in LLVM:
* lattice for `BitTracker::BitValue` in `Hexagon/BitTracker.h`
* lattice for constant propagation in `HexagonConstPropagation.cpp`
* lattice in `VarLocBasedImpl.cpp`
* lattice for address space inference code in `InferAddressSpaces.cpp`

Reviewed By: silvas, jpienaar

Differential Revision: https://reviews.llvm.org/D110766

diff --git a/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td b/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
index a9c82bf..606f906 100644 (file)
--- a/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
+++ b/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
@@ -397,7 +397,34 @@ def Shape_IndexToSizeOp : Shape_Op<"index_to_size", [NoSideEffect]> {
   let hasCanonicalizer = 1;
 }
 
-def Shape_JoinOp : Shape_Op<"join",
+def Shape_MaxOp : Shape_Op<"max",
+    [Commutative, NoSideEffect,
+     DeclareOpInterfaceMethods<InferTypeOpInterface>]> {
+  let summary = "Elementwise maximum";
+  let description = [{
+    Computes the elementwise maximum of two sizes or shapes with equal ranks.
+    If either operand is an error, then an error will be propagated to the
+    result. If the input types mismatch or the ranks do not match, then the
+    result is an error.
+  }];
+
+  let arguments = (ins Shape_ShapeOrSizeType:$lhs, Shape_ShapeOrSizeType:$rhs);
+  let results = (outs Shape_ShapeOrSizeType:$result);
+
+  let assemblyFormat = [{
+    $lhs `,` $rhs attr-dict `:` type($lhs) `,` type($rhs) `->` type($result)
+  }];
+
+  let hasFolder = 1;
+
+  let extraClassDeclaration = [{
+    // Returns when two result types are compatible for this op; method used by
+    // InferTypeOpInterface
+    static bool isCompatibleReturnTypes(TypeRange l, TypeRange r);
+  }];
+}
+
+def Shape_MeetOp : Shape_Op<"meet",
     [Commutative, DeclareOpInterfaceMethods<InferTypeOpInterface>]> {
   let summary = "Returns the least general shape.shape of its operands";
   let description = [{
@@ -408,21 +435,21 @@ def Shape_JoinOp : Shape_Op<"join",
     contradictory requirements. E.g., using pseudo code
 
     ```
-    shape.join([*], [*]) -> [*]
-    shape.join([*], [1, ?]) -> [1, ?]
-    shape.join([1, 2], [1, ?]) -> [1, 2]
-    shape.join([*], [1, 2]) -> [1, 2]
-    shape.join([], []) -> []
-    shape.join([], [*]) -> []
-    shape.join([], [?, ?]) -> [invalid]
-    shape.join([1, ?], [2, ?, ?]) -> [invalid]
+    shape.meet([*], [*]) -> [*]
+    shape.meet([*], [1, ?]) -> [1, ?]
+    shape.meet([1, 2], [1, ?]) -> [1, 2]
+    shape.meet([*], [1, 2]) -> [1, 2]
+    shape.meet([], []) -> []
+    shape.meet([], [*]) -> []
+    shape.meet([], [?, ?]) -> [invalid]
+    shape.meet([1, ?], [2, ?, ?]) -> [invalid]
     ```
 
-    `shape.join` also allows specifying an optional error string, that may be
+    `shape.meet` also allows specifying an optional error string, that may be
     used to return an error to the user upon mismatch of dimensions.
 
     ```mlir
-    %c = shape.join %a, %b, error="<reason>" : !shape.shape, !shape.shape -> !shape.shape
+    %c = shape.meet %a, %b, error="<reason>" : !shape.shape, !shape.shape -> !shape.shape
     ```
   }];
 
@@ -442,33 +469,6 @@ def Shape_JoinOp : Shape_Op<"join",
   }];
 }
 
-def Shape_MaxOp : Shape_Op<"max",
-    [Commutative, NoSideEffect,
-     DeclareOpInterfaceMethods<InferTypeOpInterface>]> {
-  let summary = "Elementwise maximum";
-  let description = [{
-    Computes the elementwise maximum of two sizes or shapes with equal ranks.
-    If either operand is an error, then an error will be propagated to the
-    result. If the input types mismatch or the ranks do not match, then the
-    result is an error.
-  }];
-
-  let arguments = (ins Shape_ShapeOrSizeType:$lhs, Shape_ShapeOrSizeType:$rhs);
-  let results = (outs Shape_ShapeOrSizeType:$result);
-
-  let assemblyFormat = [{
-    $lhs `,` $rhs attr-dict `:` type($lhs) `,` type($rhs) `->` type($result)
-  }];
-
-  let hasFolder = 1;
-
-  let extraClassDeclaration = [{
-    // Returns when two result types are compatible for this op; method used by
-    // InferTypeOpInterface
-    static bool isCompatibleReturnTypes(TypeRange l, TypeRange r);
-  }];
-}
-
 def Shape_MinOp : Shape_Op<"min",
     [Commutative, NoSideEffect,
      DeclareOpInterfaceMethods<InferTypeOpInterface>]> {

diff --git a/mlir/lib/Dialect/Shape/IR/Shape.cpp b/mlir/lib/Dialect/Shape/IR/Shape.cpp
index d3229ea..59a979c 100644 (file)
--- a/mlir/lib/Dialect/Shape/IR/Shape.cpp
+++ b/mlir/lib/Dialect/Shape/IR/Shape.cpp
@@ -1177,10 +1177,10 @@ OpFoldResult IsBroadcastableOp::fold(ArrayRef<Attribute> operands) {
 }
 
 //===----------------------------------------------------------------------===//
-// JoinOp
+// MeetOp
 //===----------------------------------------------------------------------===//
 
-LogicalResult mlir::shape::JoinOp::inferReturnTypes(
+LogicalResult mlir::shape::MeetOp::inferReturnTypes(
     MLIRContext *context, Optional<Location> location, ValueRange operands,
     DictionaryAttr attributes, RegionRange regions,
     SmallVectorImpl<Type> &inferredReturnTypes) {
@@ -1188,7 +1188,7 @@ LogicalResult mlir::shape::JoinOp::inferReturnTypes(
   return success();
 }
 
-bool mlir::shape::JoinOp::isCompatibleReturnTypes(TypeRange l, TypeRange r) {
+bool mlir::shape::MeetOp::isCompatibleReturnTypes(TypeRange l, TypeRange r) {
   if (l.size() != 1 || r.size() != 1)
     return false;
   if (l == r)

diff --git a/mlir/test/Dialect/Shape/ops.mlir b/mlir/test/Dialect/Shape/ops.mlir
index 24e7c2a..e7b501e 100644 (file)
--- a/mlir/test/Dialect/Shape/ops.mlir
+++ b/mlir/test/Dialect/Shape/ops.mlir
@@ -65,7 +65,7 @@ func @test_broadcast_extents() -> tensor<?xindex> {
 func @test_shape_any_fixed() {
   %0 = shape.const_shape [4, 57, 92] : !shape.shape
   %1 = shape.const_shape [4, 57, 92] : !shape.shape
-  %2 = "shape.join"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = "shape.meet"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
   %3 = "shape.print"(%2) : (!shape.shape) -> !shape.shape
   return
 }
@@ -73,7 +73,7 @@ func @test_shape_any_fixed() {
 func @test_shape_any_unknown() {
   %0 = shape.const_shape [4, -1, 92] : !shape.shape
   %1 = shape.const_shape [-1, 57, 92] : !shape.shape
-  %2 = "shape.join"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = "shape.meet"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
   %3 = "shape.print"(%2) : (!shape.shape) -> !shape.shape
   return
 }
@@ -81,7 +81,7 @@ func @test_shape_any_unknown() {
 func @test_shape_any_fixed_mismatch() {
   %0 = shape.const_shape [4, 57, 92] : !shape.shape
   %1 = shape.const_shape [2, 57, 92] : !shape.shape
-  %2 = "shape.join"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = "shape.meet"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
   %3 = "shape.print"(%2) : (!shape.shape) -> !shape.shape
   return
 }
@@ -243,7 +243,7 @@ func @num_elements_shape(%arg : !shape.shape) -> !shape.size {
 func @shape_equal_shapes(%a : !shape.value_shape, %b : !shape.value_shape) -> !shape.shape {
   %0 = shape.shape_of %a : !shape.value_shape -> !shape.shape
   %1 = shape.shape_of %b : !shape.value_shape -> !shape.shape
-  %2 = "shape.join"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = "shape.meet"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
   return %2 : !shape.shape
 }
 func @shape_with_shape(%a : !shape.value_shape, %b : !shape.value_shape) -> !shape.shape {
@@ -293,7 +293,7 @@ func @is_broadcastable_on_shapes(%a : !shape.shape,
 func @shape_upper_bounded_by_constant(%a: !shape.shape) -> !shape.shape {
   %0 = shape.const_shape [4, 57, 92] : !shape.shape
   %1 = shape.max %a, %0 : !shape.shape, !shape.shape -> !shape.shape
-  %2 = shape.join %0, %1, error="exceeded element-wise upper bound" :
+  %2 = shape.meet %0, %1, error="exceeded element-wise upper bound" :
     !shape.shape, !shape.shape -> !shape.shape
   return %2 : !shape.shape
 }
@@ -301,7 +301,7 @@ func @shape_upper_bounded_by_constant(%a: !shape.shape) -> !shape.shape {
 func @shape_lower_bounded_by_constant(%a: !shape.shape) -> !shape.shape {
   %0 = shape.const_shape [4, 57, 92] : !shape.shape
   %1 = shape.min %a, %0 : !shape.shape, !shape.shape -> !shape.shape
-  %2 = shape.join %0, %1, error="lower bound element-wise exceeded" :
+  %2 = shape.meet %0, %1, error="lower bound element-wise exceeded" :
     !shape.shape, !shape.shape -> !shape.shape
   return %2 : !shape.shape
 }
@@ -309,7 +309,7 @@ func @shape_lower_bounded_by_constant(%a: !shape.shape) -> !shape.shape {
 func @size_upper_bounded_by_constant(%a: !shape.size) -> !shape.size {
   %0 = shape.const_size 5
   %1 = shape.max %a, %0 : !shape.size, !shape.size -> !shape.size
-  %2 = shape.join %0, %1, error="exceeded element-wise upper bound" :
+  %2 = shape.meet %0, %1, error="exceeded element-wise upper bound" :
     !shape.size, !shape.size -> !shape.size
   return %2 : !shape.size
 }
@@ -317,7 +317,7 @@ func @size_upper_bounded_by_constant(%a: !shape.size) -> !shape.size {
 func @size_lower_bounded_by_constant(%a: !shape.size) -> !shape.size {
   %0 = shape.const_size 9
   %1 = shape.min %a, %0 : !shape.size, !shape.size -> !shape.size
-  %2 = shape.join %0, %1, error="lower bound element-wise exceeded" :
+  %2 = shape.meet %0, %1, error="lower bound element-wise exceeded" :
     !shape.size, !shape.size -> !shape.size
   return %2 : !shape.size
 }