Implement ConditionallySpeculatable for remaining dynamic ops (#2242)

Included ops:
- DynamicPad
- RealDynamicSlice
- DynamicConv
- DynamicGather

I refactored the logic to check speculatability for shaped ops to enable
reuse and allow ops with more than one shape-related operand to be
checked.

This is the last change adding new speculatability
implementations. All the other ops are either done, pure, or
deprecated.

stablehlo/dialect/Base.cpp

@@ -611,5 +611,22 @@ bool isSplatArray(ArrayRef<int64_t> arr, int64_t val) {
                      [val](int64_t x) { return x == val; });
 }
 
+mlir::Speculation::Speculatability getShapedSpeculatability(
+    Operation* op, int64_t shapeCount) {
+  // If all inputs are static and the shape-related operands are constant
+  // then any relationship between the input, the shapes and the output can be
+  // verified statically.
+  bool allInputsStatic = llvm::all_of(op->getOperandTypes(), [](Type t) {
+    return cast<ShapedType>(t).hasStaticShape();
+  });
+  bool allShapesConstant = llvm::all_of(llvm::seq(shapeCount), [&](int64_t i) {
+    return matchPattern(op->getOperand(op->getNumOperands() - 1 - i),
+                        m_Constant());
+  });
+  return allInputsStatic && allShapesConstant
+             ? mlir::Speculation::Speculatable
+             : mlir::Speculation::NotSpeculatable;
+}
+
 }  // namespace hlo
 }  // namespace mlir

stablehlo/dialect/Base.h

@@ -255,6 +255,13 @@ void writeEnumAttribute(EnumTypeAttr val, DialectBytecodeWriter &writer) {
 }
 }  // namespace bytecode
 
+// Determines the speculatability for a shaped operation `op` with `shapeCount`
+// shape operands. The last `count` operands are assumed to be shape operands.
+// To be speculatable, such an op must have only static inputs and constant
+// shape operands.
+mlir::Speculation::Speculatability getShapedSpeculatability(Operation *op,
+                                                            int64_t shapeCount);
+
 namespace OpTrait {
 
 template <typename ConcreteType>
@@ -470,6 +477,16 @@ struct RecursivelySpeculatableIfAllInputsStaticImplTrait
   }
 };
 
+template <typename ConcreteType>
+struct SpeculatableIfAllInputsStaticAndShapeConstantImplTrait
+    : public mlir::OpTrait::TraitBase<
+          ConcreteType,
+          SpeculatableIfAllInputsStaticAndShapeConstantImplTrait> {
+  mlir::Speculation::Speculatability getSpeculatability() {
+    return getShapedSpeculatability(this->getOperation(), 1);
+  }
+};
+
 }  // namespace OpTrait
 }  // namespace hlo
 }  // namespace mlir

stablehlo/dialect/Base.td

@@ -368,4 +368,13 @@ def HLO_RecursivelySpeculatableIfAllInputsStaticImplTrait
 def HLO_RecursivelySpeculatableIfAllInputsStatic : TraitList<[
     ConditionallySpeculatable, HLO_RecursivelySpeculatableIfAllInputsStaticImplTrait]>;
 
+def HLO_SpeculatableIfAllInputsStaticAndShapeConstantImplTrait
+  : HLO_NativeOpTrait<"SpeculatableIfAllInputsStaticAndShapeConstantImplTrait">;
+
+// This trait is the same as HLO_SpeculatableIfAllInputsStatic, but for ops that
+// take a shape as their last operand. Such ops are speculatable if all inputs
+// are static and the shape is constant.
+def HLO_SpeculatableIfAllInputsStaticAndShapeConstant : TraitList<[
+    ConditionallySpeculatable, HLO_SpeculatableIfAllInputsStaticAndShapeConstantImplTrait]>;
+
 #endif // STABLEHLO_DIALECT_BASE

stablehlo/dialect/StablehloOps.cpp

@@ -1532,18 +1532,6 @@ LogicalResult DynamicReshapeOp::reifyReturnTypeShapes(
   return success();
 }
 
-mlir::Speculation::Speculatability DynamicReshapeOp::getSpeculatability() {
-  // If the input is static and the shape operand is constant, the output
-  // shape can be inferred and any mismatch will be caught statically.
-  // If any dimension in the input is dynamic, or if the shape is not known,
-  // the number of elements may disagree at runtime.
-  if (getOperand().getType().hasStaticShape() &&
-      matchPattern(getOutputShape(), m_Constant()))
-    return mlir::Speculation::Speculatable;
-
-  return mlir::Speculation::NotSpeculatable;
-}
-
 //===----------------------------------------------------------------------===//
 // DynamicSliceOp
 //===----------------------------------------------------------------------===//
@@ -1613,6 +1601,10 @@ LogicalResult RealDynamicSliceOp::reifyReturnTypeShapes(
   return success();
 }
 
+mlir::Speculation::Speculatability RealDynamicSliceOp::getSpeculatability() {
+  return hlo::getShapedSpeculatability(getOperation(), /*shapeCount=*/3);
+}
+
 //===----------------------------------------------------------------------===//
 // InfeedOp
 //===----------------------------------------------------------------------===//
@@ -2160,6 +2152,10 @@ LogicalResult DynamicPadOp::reifyReturnTypeShapes(
   return success();
 }
 
+mlir::Speculation::Speculatability DynamicPadOp::getSpeculatability() {
+  return hlo::getShapedSpeculatability(getOperation(), /*shapeCount=*/3);
+}
+
 //===----------------------------------------------------------------------===//
 // ReshapeOp
 //===----------------------------------------------------------------------===//

stablehlo/dialect/StablehloOps.td

@@ -145,7 +145,7 @@ def StableHLO_DynamicIotaOp: StableHLO_ShapedInterfaceOp<"dynamic_iota", [Condit
     $output_shape `,` `dim` `=` $iota_dimension attr-dict `:` functional-type(operands, results)
   }];
 
-  let extraClassDeclaration = [{
+  let extraClassDeclaration = commonClassDeclaration # [{
     /// Interface method for ConditionallySpeculatable.
     mlir::Speculation::Speculatability getSpeculatability();
   }];
@@ -2653,7 +2653,7 @@ def StableHLO_ReshapeOp: StableHLO_Op<"reshape",
 }
 
 def StableHLO_DynamicReshapeOp: StableHLO_ShapedInterfaceOp<"dynamic_reshape",
-      [ConditionallySpeculatable, NoMemoryEffect]> {
+      [HLO_SpeculatableIfAllInputsStaticAndShapeConstant, NoMemoryEffect]> {
   let summary = "DynamicReshape operation";
   let description = [{
     This operation is a work in progress, so it is not yet included in
@@ -2675,11 +2675,6 @@ def StableHLO_DynamicReshapeOp: StableHLO_ShapedInterfaceOp<"dynamic_reshape",
   let hasVerifier = 1;
 
   let assemblyFormat = "operands attr-dict `:` functional-type(operands, results)";
-
-  let extraClassDeclaration = commonClassDeclaration # [{
-    /// Interface method for ConditionallySpeculatable.
-    mlir::Speculation::Speculatability getSpeculatability();
-  }];
 }
 
 def StableHLO_ScatterOp: StableHLO_Op<"scatter",
@@ -3375,7 +3370,8 @@ def StableHLO_ReducePrecisionOp : StableHLO_Op<"reduce_precision",
 
 def StableHLO_RealDynamicSliceOp: StableHLO_ShapedInterfaceOp<
       "real_dynamic_slice",
-      [Pure, AllElementTypesMatch<["operand", "result"]>,
+      [ConditionallySpeculatable, NoMemoryEffect,
+       AllElementTypesMatch<["operand", "result"]>,
        AllTypesMatch<["start_indices", "limit_indices", "strides"]>]> {
   let summary = "RealDynamicSlice operation";
   let description = [{
@@ -3403,10 +3399,16 @@ def StableHLO_RealDynamicSliceOp: StableHLO_ShapedInterfaceOp<
   let hasVerifier = 1;
 
   let assemblyFormat = "operands attr-dict `:` functional-type(operands, results)";
+
+  let extraClassDeclaration = commonClassDeclaration # [{
+    /// Interface method for ConditionallySpeculatable.
+    mlir::Speculation::Speculatability getSpeculatability();
+  }];
 }
 
 def StableHLO_DynamicPadOp: StableHLO_ShapedInterfaceOp<"dynamic_pad",
-      [Pure, AllElementTypesMatch<["operand", "padding_value", "result"]>,
+      [ConditionallySpeculatable, NoMemoryEffect,
+      AllElementTypesMatch<["operand", "padding_value", "result"]>,
       AllTypesMatch<["edge_padding_low", "edge_padding_high", "interior_padding"]>]> {
   let summary = "DynamicPad operation";
   let description = [{
@@ -3440,10 +3442,16 @@ def StableHLO_DynamicPadOp: StableHLO_ShapedInterfaceOp<"dynamic_pad",
   let hasVerifier = 1;
 
   let assemblyFormat = "operands attr-dict `:` functional-type(operands, results)";
+
+  let extraClassDeclaration = commonClassDeclaration # [{
+    /// Interface method for ConditionallySpeculatable.
+    mlir::Speculation::Speculatability getSpeculatability();
+  }];
 }
 
 def StableHLO_DynamicGatherOp: StableHLO_Op<"dynamic_gather",
-                                [InferTensorTypeWithReify, Pure]> {
+      [HLO_SpeculatableIfAllInputsStaticAndShapeConstant, NoMemoryEffect,
+      InferTensorTypeWithReify]> {
   let summary = "DynamicGather operation";
   let description = [{
     This operation is a work in progress, so it is not yet included in
@@ -3476,7 +3484,8 @@ def StableHLO_DynamicGatherOp: StableHLO_Op<"dynamic_gather",
   let results = (outs HLO_Tensor);
 }
 
-def StableHLO_DynamicConvOp : StableHLO_Op<"dynamic_conv", [Pure]> {
+def StableHLO_DynamicConvOp : StableHLO_Op<"dynamic_conv",
+      [HLO_SpeculatableIfAllInputsStaticAndShapeConstant, NoMemoryEffect]> {
   let summary = "DynamicConv operation";
   let description = [{
     This operation is a work in progress, so it is not yet included in