[mlir][openacc] Add host_data operation

[clementval]

Summary

The acc.host_data operation models the OpenACC
host_data construct (2.8). The host_data construct
defines a region where the address of data in device memory
available on the host. The operation is modeled in a similar way
than acc.data operation.

[clementval]

Update example

[razvanlupusoru]

Awesome! Glad to see that the data operation model extends to these operations as well.

[jeanPerier]

Looks great

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

 def OpenACC_NoCreateClause        : I64EnumAttrCase<"acc_no_create", 12>;
 def OpenACC_PrivateClause         : I64EnumAttrCase<"acc_private", 13>;
 def OpenACC_FirstPrivateClause    : I64EnumAttrCase<"acc_firstprivate", 14>;
 def OpenACC_IsDevicePtrClause     : I64EnumAttrCase<"acc_deviceptr", 15>;
 def OpenACC_GetDevicePtrClause    : I64EnumAttrCase<"acc_getdeviceptr", 16>;
 def OpenACC_UpdateHost            : I64EnumAttrCase<"acc_update_host", 17>;
 def OpenACC_UpdateSelf            : I64EnumAttrCase<"acc_update_self", 18>;
 def OpenACC_UpdateDevice          : I64EnumAttrCase<"acc_update_device", 19>;
+def OpenACC_UseDevice             : I64EnumAttrCase<"acc_use_device", 20>;
 
 def OpenACC_DataClauseEnum : I64EnumAttr<"DataClause",
     "data clauses supported by OpenACC",
     [OpenACC_CopyinClause, OpenACC_CopyinReadonlyClause, OpenACC_CopyClause,
      OpenACC_CopyoutClause, OpenACC_CopyoutZeroClause, OpenACC_PresentClause,
      OpenACC_CreateClause, OpenACC_CreateZeroClause, OpenACC_DeleteClause,
      OpenACC_AttachClause, OpenACC_DetachClause, OpenACC_NoCreateClause,
      OpenACC_PrivateClause, OpenACC_FirstPrivateClause,
      OpenACC_IsDevicePtrClause, OpenACC_GetDevicePtrClause, OpenACC_UpdateHost,
-     OpenACC_UpdateSelf, OpenACC_UpdateDevice,
+     OpenACC_UpdateSelf, OpenACC_UpdateDevice, OpenACC_UseDevice,
     ]> {
   let cppNamespace = "::mlir::acc";
 }
 
 // Used for data specification in data clauses (2.7.1).
 // Either (or both) extent and upperbound must be specified.
 def OpenACC_DataBoundsOp : OpenACC_Op<"bounds",
     [AttrSizedOperandSegments, NoMemoryEffect]> {

 //===----------------------------------------------------------------------===//
 // 2.14.4 device clause
 //===----------------------------------------------------------------------===//
 def OpenACC_UpdateDeviceOp : OpenACC_DataEntryOp<"update_device",
     "mlir::acc::DataClause::acc_update_device"> {
   let summary = "Represents acc update device semantics.";
 }
 
+//===----------------------------------------------------------------------===//
+// 2.8 use_device clause
+//===----------------------------------------------------------------------===//
+def OpenACC_UseDeviceOp : OpenACC_DataEntryOp<"use_device",
+    "mlir::acc::DataClause::acc_use_device"> {
+  let summary = "Represents acc use_device semantics.";
+}
+
 // Data exit operation does not refer to OpenACC spec terminology, but to
 // terminology used in this dialect. It refers to data operations that will appear
 // after data or compute region. It will be used as the base of acc dialect
 // operations for the following OpenACC data clauses: copyout, detach, delete.
 class OpenACC_DataExitOp<string mnemonic, string clause, list<Trait> traits = []> :
     OpenACC_Op<mnemonic, !listconcat(traits,
         [AttrSizedOperandSegments])> {
   let arguments = (ins OpenACC_PointerLikeTypeInterface:$accPtr,
let assemblyFormat = [{
     attr-dict-with-keyword
   }];
 
   let hasCanonicalizer = 1;
   let hasVerifier = 1;
 }
 
 //===----------------------------------------------------------------------===//
+// 2.8 Host_Data Construct
+//===----------------------------------------------------------------------===//
+
+def OpenACC_HostDataOp : OpenACC_Op<"host_data", [AttrSizedOperandSegments]> {
+  let summary = "host_data construct";
+
+  let description = [{
+    The "acc.host_data" operation represents the OpenACC host_data construct.
+
+    Example:
+
+    ```mlir
+    acc.host_data dataOperands() {
+
+    }
+    ```
+  }];
+
+  let arguments = (ins Optional<I1>:$ifCond,
+                       Variadic<OpenACC_PointerLikeTypeInterface>:$dataOperands,
+                       UnitAttr:$ifPresent);
+
+  let regions = (region AnyRegion:$region);
+
+  let assemblyFormat = [{
+    oilist(
+        `if` `(` $ifCond `)`
+      | `dataOperands` `(` $dataOperands `:` type($dataOperands) `)`
+    )
+    $region attr-dict-with-keyword
+  }];
+
+  let hasVerifier = 1;
+}
+
+//===----------------------------------------------------------------------===//
 // 2.9 loop Construct
 //===----------------------------------------------------------------------===//
 
 def OpenACC_LoopOp : OpenACC_Op<"loop",
     [AttrSizedOperandSegments, RecursiveMemoryEffects]> {
   let summary = "loop construct";
 
   let description = [{

mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp

LogicalResult acc::UpdateDeviceOp::verify() {
   // Test for all clauses this operation can be decomposed from:
   if (getDataClause() != acc::DataClause::acc_update_device)
     return emitError(
         "data clause associated with device operation must match its intent"
         " or specify original clause this operation was decomposed from");
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// UseDeviceOp
+//===----------------------------------------------------------------------===//
+LogicalResult acc::UseDeviceOp::verify() {
+  // Test for all clauses this operation can be decomposed from:
+  if (getDataClause() != acc::DataClause::acc_use_device)
+    return emitError(
+        "data clause associated with use_device operation must match its intent"
+        " or specify original clause this operation was decomposed from");
+  return success();
+}
+
 template <typename StructureOp>
 static ParseResult parseRegions(OpAsmParser &parser, OperationState &state,
                                 unsigned nRegions = 1) {
 
   SmallVector<Region *, 2> regions;
   for (unsigned i = 0; i < nRegions; ++i)
     regions.push_back(state.addRegion());
 
Value KernelsOp::getDataOperand(unsigned i) {
   return getOperand(getWaitOperands().size() + numOptional + i);
 }
 
 LogicalResult acc::KernelsOp::verify() {
   return checkDataOperands<acc::KernelsOp>(*this, getDataClauseOperands());
 }
 
 //===----------------------------------------------------------------------===//
+// HostDataOp
+//===----------------------------------------------------------------------===//
+
+LogicalResult acc::HostDataOp::verify() {
+  if (getDataOperands().empty())
+    return emitError("at least one operand must appear on the host_data "
+                     "operation");
+
+  for (mlir::Value operand : getDataOperands())
+    if (!mlir::isa<acc::UseDeviceOp>(operand.getDefiningOp()))
+      return emitError("expect data entry operation as defining op");
+  return success();
+}
+
+//===----------------------------------------------------------------------===//
 // LoopOp
 //===----------------------------------------------------------------------===//
 
 static ParseResult
 parseGangClause(OpAsmParser &parser,
                 std::optional<OpAsmParser::UnresolvedOperand> &gangNum,
                 Type &gangNumType,
                 std::optional<OpAsmParser::UnresolvedOperand> &gangStatic,

mlir/test/Dialect/OpenACC/ops.mlir

func.func @host_device_ops(%a: memref<10xf32>) -> () {
   %devptr = acc.getdeviceptr varPtr(%a : memref<10xf32>) -> memref<10xf32> {dataClause = 16}
   acc.update_host accPtr(%devptr : memref<10xf32>) to varPtr(%a : memref<10xf32>) {structured = false}
   acc.update dataOperands(%devptr : memref<10xf32>)
 
   %accPtr = acc.update_device varPtr(%a : memref<10xf32>) -> memref<10xf32>
   acc.update dataOperands(%accPtr : memref<10xf32>)
   return
 }
+
+// -----
+
+func.func @host_data_ops(%a: !llvm.ptr<f32>, %ifCond: i1) -> () {
+  %0 = acc.use_device varPtr(%a : !llvm.ptr<f32>) -> !llvm.ptr<f32>
+  acc.host_data dataOperands(%0: !llvm.ptr<f32>) {
+  }
+  acc.host_data dataOperands(%0: !llvm.ptr<f32>) {
+  } attributes {if_present}
+  acc.host_data if(%ifCond) dataOperands(%0: !llvm.ptr<f32>) {
+  }
+  return
+}
+
+// CHECK-LABEL: func.func @host_data_ops(
+// CHECK-SAME:    %[[A:.*]]: !llvm.ptr<f32>, %[[IFCOND:.*]]: i1)
+// CHECK: %[[PTR:.*]] = acc.use_device varPtr(%[[A]] : !llvm.ptr<f32>) -> !llvm.ptr<f32>
+// CHECK: acc.host_data dataOperands(%[[PTR]] : !llvm.ptr<f32>)
+// CHECK: acc.host_data dataOperands(%[[PTR]] : !llvm.ptr<f32>) {
+// CHECK: } attributes {if_present}
+// CHECK: acc.host_data if(%[[IFCOND]]) dataOperands(%[[PTR]] : !llvm.ptr<f32>)