[Func][GPU] Create func::ConstantOp using parents with SymbolTable trait

Author: Artem Kroviakov

mlir/lib/Dialect/Func/IR/FuncOps.cpp

@@ -128,7 +128,9 @@ LogicalResult ConstantOp::verify() {
   Type type = getType();
 
   // Try to find the referenced function.
-  auto fn = (*this)->getParentOfType<ModuleOp>().lookupSymbol<FuncOp>(fnName);
+  SymbolTable symbolTable(
+      (*this)->getParentWithTrait<mlir::OpTrait::SymbolTable>());
+  auto fn = symbolTable.lookup<FuncOp>(fnName);
   if (!fn)
     return emitOpError() << "reference to undefined function '" << fnName
                          << "'";

mlir/test/Dialect/GPU/indirect-device-func-call.mlir

@@ -0,0 +1,21 @@
+// RUN: mlir-opt -test-gpu-rewrite -convert-func-to-llvm %s | FileCheck %s
+
+gpu.module @kernels {
+    // CHECK-LABEL: @hello
+    // CHECK-SAME: %[[ARG0:.*]]: f32
+    func.func @hello(%arg0 : f32) {
+        %tid_x = gpu.thread_id x
+        %csti8 = arith.constant 2 : i8
+        gpu.printf "Hello from %lld, %d, %f\n" %tid_x, %csti8, %arg0  : index, i8, f32
+        return
+    }
+    // CHECK-LABEL: @hello_indirect
+    gpu.func @hello_indirect() kernel { 
+        %cstf32 = arith.constant 3.0 : f32
+        // CHECK: %[[DEVICE_FUNC_ADDR:.*]] = llvm.mlir.addressof @hello : !llvm.ptr
+        %func_ref = func.constant @hello : (f32) -> ()
+        // CHECK: llvm.call %[[DEVICE_FUNC_ADDR]](%{{.*}}) : !llvm.ptr, (f32) -> ()
+        func.call_indirect %func_ref(%cstf32) : (f32) -> ()
+        gpu.return
+    }
+}