#sdy Support OpShardingRule in SDY round trip import.

xla/service/spmd/shardy/sdy_round_trip/import_shardings.cc

@@ -71,15 +71,17 @@ using ::mlir::func::FuncOp;
 using ::mlir::mhlo::CustomCallOp;
 
 using ::mlir::sdy::kShardingAttr;
+using ::mlir::sdy::kShardingRuleAttr;
 using ::mlir::sdy::MeshAttr;
+using ::mlir::sdy::OpShardingRuleAttr;
 using ::mlir::sdy::TensorShardingAttr;
 using ::mlir::sdy::TensorShardingPerValueAttr;
 
-// Builds the shardings coming from Shardy previously. This means
+// Builds the shardy attributes coming from Shardy previously. This means
 // the module was exported from Shardy and we are now round-tripping back.
 // This should happen after the meshes were created from the `ModuleOp` attrs
 // (see `SdyRoundTripImportShardingsPass`).
-void convertShardings(FuncOp funcOp) {
+void convertShardyAttrs(FuncOp funcOp) {
   // Copy over the argument shardings, but not the result shardings yet.
   // We need to wait until after we've converted all the Operations before
   // copying the result shardings.
@@ -102,7 +104,7 @@ void convertShardings(FuncOp funcOp) {
         resNum, StringAttr::get(funcOp.getContext(), kXlaShardingAttr));
   }
 
-  // Extract the round-tripped SDY shardings from the operations.
+  // Extract the round-tripped SDY shardy attributes from the operations.
   funcOp.front().walk([&](Operation* op) {
     op->removeAttr(kXlaShardingAttr);
     if (DictionaryAttr dictAttr = getFrontendAttrs(op)) {
@@ -141,6 +143,13 @@ void convertShardings(FuncOp funcOp) {
         }
       }
       removeFrontendAttribute(op, kShardingRoundTripAttr);
+
+      // Import sharding rules.
+      if (auto shardingRuleAttr = parseStringAttr<OpShardingRuleAttr>(
+              dictAttr, kShardingRuleRoundTripAttr)) {
+        op->setAttr(kShardingRuleAttr, shardingRuleAttr);
+        removeFrontendAttribute(op, kShardingRuleRoundTripAttr);
+      }
     }
   });
 }
@@ -176,14 +185,15 @@ class SdyRoundTripImportShardingsPass
     // Insert the meshes before any functions.
     builder.setInsertionPointToStart(moduleOp.getBody());
     for (NamedAttribute mesh : sdyMeshes) {
+      mesh.getValue().dump();
       auto meshAttr = mlir::cast<MeshAttr>(mesh.getValue());
       symbolTable.insert(builder.create<mlir::sdy::MeshOp>(
           moduleOp.getLoc(), mesh.getName(), meshAttr));
     }
     removeFrontendAttribute(moduleOp, kMeshesRoundTripAttr);
 
     for (auto funcOp : moduleOp.getOps<FuncOp>()) {
-      convertShardings(funcOp);
+      convertShardyAttrs(funcOp);
     }
   }
 

xla/service/spmd/shardy/sdy_round_trip/import_shardings.h

@@ -23,8 +23,12 @@ limitations under the License.
 namespace xla {
 namespace sdy {
 
-// Creates the pass that converts the shardings from strings in MHLO frontend
-// attributes to SDY meshes and shardings.
+// Creates the pass to convert frontend attributes to SDY attributes:
+//
+// - Converts shardings from `kShardingRoundTripAttr` to `kShardingAttr`
+// - Converts sharding rules from `kShardingRuleRoundTripAttr` to
+//   `kShardingRuleAttr`
+// - Converts meshes from `kMeshesRoundTripAttr` to sdy.mesh symbols
 std::unique_ptr<mlir::Pass> createSdyRoundTripImportShardingsPass();
 
 // Registers the xla-sdy-round-trip-import-shardings pass.

xla/service/spmd/shardy/test/sdy_round_trip_import_pipeline.mlir

@@ -1,4 +1,4 @@
-// RUN: sdy_opt %s -xla-sdy-round-trip-import-pipeline 2>&1 | FileCheck %s
+// RUN: sdy_opt %s --split-input-file -xla-sdy-round-trip-import-pipeline 2>&1 | FileCheck %s
 
 // CHECK-LABEL: module @multiple_func_result_shardings
 module @multiple_func_result_shardings attributes {mhlo.frontend_attributes = {xla.sdy.meshes = "{mesh = #sdy.mesh<[\\\22a\\\22=8, \\\22b\\\22=8, \\\22c\\\22=8]>}"}} {
@@ -110,3 +110,22 @@ module @multiple_func_result_shardings attributes {mhlo.frontend_attributes = {x
     return %3 : tensor<32xi32>
   }
 }
+
+// -----
+
+module @no_mesh_module attributes {mhlo.frontend_attributes = {xla.sdy.meshes = "{}"}} {
+  // CHECK-LABEL: func @no_sharding_rule
+  func.func @no_sharding_rule(%arg0: tensor<8x2xf32>, %arg1: tensor<8x2xf32>) -> tensor<8x2xf64> {
+    // CHECK-NEXT: stablehlo.custom_call @foo(%arg0, %arg1) : (tensor<8x2xf32>, tensor<8x2xf32>) -> tensor<8x2xf64>
+    %0 = stablehlo.custom_call @foo(%arg0, %arg1) : (tensor<8x2xf32>, tensor<8x2xf32>) -> tensor<8x2xf64>
+   return %0 : tensor<8x2xf64>
+  }
+
+  // CHECK-LABEL: func @op_sharding_rule
+  func.func @op_sharding_rule(%arg0: tensor<8x2xf32>, %arg1: tensor<8x2xf32>) -> tensor<8x2xf64> {
+    // CHECK-NEXT: stablehlo.custom_call @foo(%arg0, %arg1) {sdy.sharding_rule = #sdy.op_sharding_rule<([i, j], [i, j])->([i, j]) {i=8, j=2}>}
+    %0 = stablehlo.custom_call @foo(%arg0, %arg1)
+      {mhlo.frontend_attributes = {xla.sdy.sharding_rule = "#sdy.op_sharding_rule<([i, j], [i, j])->([i, j]) {i=8, j=2}>"}} : (tensor<8x2xf32>, tensor<8x2xf32>) -> tensor<8x2xf64>
+    return %0 : tensor<8x2xf64>
+  }
+}

xla/service/spmd/shardy/utils.h

@@ -61,25 +61,20 @@ void removeFrontendAttribute(mlir::func::FuncOp funcOp,
 
 void loadAllRequiredDialects(mlir::MLIRContext* context);
 
-// Parses `stringAttr` to an attribute of type `AttrTy`.
-//
-// NOTE: assumes `stringAttr` is of type `StringAttr`.
-template <typename AttrTy>
-AttrTy parseStringAttr(mlir::Attribute stringAttr) {
-  std::string value;
-  std::string error;
-  CHECK(absl::CUnescape(mlir::cast<mlir::StringAttr>(stringAttr).getValue(),
-                        &value, &error))
-      << error;
-  return mlir::cast<AttrTy>(
-      mlir::parseAttribute(value, stringAttr.getContext()));
-}
-
 // Parses `attrName` from `dictAttr` to an attribute of type `AttrTy`.
 template <typename AttrTy>
 AttrTy parseStringAttr(mlir::DictionaryAttr dictAttr,
                        llvm::StringRef attrName) {
-  return parseStringAttr<AttrTy>(dictAttr.get(attrName));
+  if (mlir::Attribute stringAttr = dictAttr.get(attrName)) {
+    std::string value;
+    std::string error;
+    CHECK(absl::CUnescape(mlir::cast<mlir::StringAttr>(stringAttr).getValue(),
+                          &value, &error))
+        << error;
+    return mlir::cast<AttrTy>(
+        mlir::parseAttribute(value, stringAttr.getContext()));
+  }
+  return nullptr;
 }
 
 }  // namespace sdy