[MLIR][OpenMP] Allow map operands to be not specified

This patch permits map operands to be not specified for the target
data operation. Also emit an error if none of the map, use_device_addr,
or use_device_ptr operands are specified.

Reviewed By: TIFitis

Differential Revision: https://reviews.llvm.org/D156170

Author: kiranchandramohan

flang/test/Fir/convert-to-llvm-openmp-and-fir.fir

@@ -321,6 +321,19 @@ func.func @_QPopenmp_target_data_region() {
 
 // -----
 
+func.func @_QPomp_target_data_empty() {
+  %0 = fir.alloca !fir.array<1024xi32> {bindc_name = "a", uniq_name = "_QFomp_target_data_emptyEa"}
+  omp.target_data use_device_addr(%0 : !fir.ref<!fir.array<1024xi32>>) {
+  }
+  return
+}
+
+// CHECK-LABEL:   llvm.func @_QPomp_target_data_empty
+// CHECK: omp.target_data   use_device_addr(%1 : !llvm.ptr<array<1024 x i32>>) {
+// CHECK: }
+
+// -----
+
 func.func @_QPomp_target() {
   %0 = fir.alloca !fir.array<512xi32> {bindc_name = "a", uniq_name = "_QFomp_targetEa"}
   %c64_i32 = arith.constant 64 : i32

mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td

@@ -1041,15 +1041,16 @@ def Target_DataOp: OpenMP_Op<"target_data", [AttrSizedOperandSegments]>{
                        Variadic<OpenMP_PointerLikeType>:$use_device_ptr,
                        Variadic<OpenMP_PointerLikeType>:$use_device_addr,
                        Variadic<OpenMP_PointerLikeType>:$map_operands,
-                       I64ArrayAttr:$map_types);
+                       OptionalAttr<I64ArrayAttr>:$map_types);
 
   let regions = (region AnyRegion:$region);
 
   let assemblyFormat = [{
     oilist(`if` `(` $if_expr `:` type($if_expr) `)`
-    | `device` `(` $device `:` type($device) `)`)
-    `map` `(` custom<MapClause>($map_operands, type($map_operands), $map_types) `)`
-    oilist(`use_device_ptr` `(` $use_device_ptr `:` type($use_device_ptr) `)`
+    | `device` `(` $device `:` type($device) `)`
+    | `map`
+      `(` custom<MapClause>($map_operands, type($map_operands), $map_types) `)`
+    | `use_device_ptr` `(` $use_device_ptr `:` type($use_device_ptr) `)`
     | `use_device_addr` `(` $use_device_addr `:` type($use_device_addr) `)`)
     $region attr-dict
   }];

mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp

@@ -800,11 +800,22 @@ static LogicalResult verifyMapClause(Operation *op, OperandRange map_operands,
                std::underlying_type_t<llvm::omp::OpenMPOffloadMappingFlags>>(
                flag);
   };
-  if (!map_types.has_value())
-    return success();
+  if (!map_types) {
+    if (!map_operands.empty())
+      return emitError(op->getLoc(), "missing mapTypes");
+    else
+      return success();
+  }
+
+  if (map_operands.empty() && !map_types->empty())
+    return emitError(op->getLoc(), "missing mapOperands");
+
+  if (map_types->empty() && !map_operands.empty())
+    return emitError(op->getLoc(), "missing mapTypes");
 
   if (map_operands.size() != map_types->size())
-    return failure();
+    return emitError(op->getLoc(),
+                     "mismatch in number of mapOperands and mapTypes");
 
   for (const auto &mapTypeOp : *map_types) {
     int64_t mapTypeBits = 0x00;
@@ -835,6 +846,11 @@ static LogicalResult verifyMapClause(Operation *op, OperandRange map_operands,
 }
 
 LogicalResult DataOp::verify() {
+  if (getMapOperands().empty() && getUseDevicePtr().empty() &&
+      getUseDeviceAddr().empty()) {
+    return ::emitError(this->getLoc(), "At least one of map, useDevicePtr, or "
+                                       "useDeviceAddr operand must be present");
+  }
   return verifyMapClause(*this, getMapOperands(), getMapTypes());
 }
 

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -1437,7 +1437,8 @@ convertOmpTargetData(Operation *op, llvm::IRBuilderBase &builder,
                   deviceID = intAttr.getInt();
 
             mapOperands = dataOp.getMapOperands();
-            mapTypes = dataOp.getMapTypes();
+            if (dataOp.getMapTypes())
+              mapTypes = dataOp.getMapTypes().value();
             return success();
           })
           .Case([&](omp::EnterDataOp enterDataOp) {

mlir/test/Dialect/OpenMP/invalid.mlir

@@ -1630,6 +1630,14 @@ func.func @omp_target_data(%map1: memref<?xi32>) {
 
 // -----
 
+func.func @omp_target_data() {
+  // expected-error @below {{At least one of map, useDevicePtr, or useDeviceAddr operand must be present}}
+  omp.target_data {}
+  return
+}
+
+// -----
+
 func.func @omp_target_enter_data(%map1: memref<?xi32>) {
   // expected-error @below {{to and alloc map types are permitted}}
   omp.target_enter_data map((from -> %map1 : memref<?xi32>)){}