[Flang] Add fir omp target alloc and free ops

This commit is CP from ivanradanov commit
be860ac

Author: skc7

flang/include/flang/Optimizer/Dialect/FIROps.td

@@ -517,6 +517,67 @@ def fir_ZeroOp : fir_OneResultOp<"zero_bits", [NoMemoryEffect]> {
   let assemblyFormat = "type($intype) attr-dict";
 }
 
+def fir_OmpTargetAllocMemOp : fir_Op<"omp_target_allocmem",
+    [MemoryEffects<[MemAlloc<DefaultResource>]>, AttrSizedOperandSegments]> {
+  let summary = "allocate storage on an openmp device for an object of a given type";
+
+  let description = [{
+    Creates a heap memory reference suitable for storing a value of the
+    given type, T.  The heap refernce returned has type `!fir.heap<T>`.
+    The memory object is in an undefined state.  `allocmem` operations must
+    be paired with `freemem` operations to avoid memory leaks.
+
+    ```
+      %0 = fir.omp_target_allocmem !fir.array<10 x f32>
+    ```
+  }];
+
+  let arguments = (ins
+    Arg<AnyIntegerType>:$device,
+    TypeAttr:$in_type,
+    OptionalAttr<StrAttr>:$uniq_name,
+    OptionalAttr<StrAttr>:$bindc_name,
+    Variadic<AnyIntegerType>:$typeparams,
+    Variadic<AnyIntegerType>:$shape
+  );
+  let results = (outs fir_HeapType);
+
+  let extraClassDeclaration = [{
+    mlir::Type getAllocatedType();
+    bool hasLenParams() { return !getTypeparams().empty(); }
+    bool hasShapeOperands() { return !getShape().empty(); }
+    unsigned numLenParams() { return getTypeparams().size(); }
+    operand_range getLenParams() { return getTypeparams(); }
+    unsigned numShapeOperands() { return getShape().size(); }
+    operand_range getShapeOperands() { return getShape(); }
+    static mlir::Type getRefTy(mlir::Type ty);
+  }];
+}
+
+def fir_OmpTargetFreeMemOp : fir_Op<"omp_target_freemem",
+  [MemoryEffects<[MemFree]>]> {
+  let summary = "free a heap object";
+
+  let description = [{
+    Deallocates a heap memory reference that was allocated by an `allocmem`.
+    The memory object that is deallocated is placed in an undefined state
+    after `fir.freemem`.  Optimizations may treat the loading of an object
+    in the undefined state as undefined behavior.  This includes aliasing
+    references, such as the result of an `fir.embox`.Add commentMore actions
+
+    ```
+      %21 = fir.omp_target_allocmem !fir.type<ZT(p:i32){field:i32}>
+      ...
+      fir.omp_target_freemem %21 : !fir.heap<!fir.type<ZT>>
+    ```
+  }];
+
+  let arguments = (ins
+  Arg<AnyIntegerType, "", [MemFree]>:$device,
+  Arg<fir_HeapType, "", [MemFree]>:$heapref
+  );
+}
+
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 // Terminator operations
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