[flang][OpenMP][Offloading][AMDGPU] Add offloading test for target update

Adds a new test for offloading `target update` directive to AMD GPUs.

Author: ergawy

mlir/lib/Conversion/OpenMPToLLVM/OpenMPToLLVM.cpp

@@ -239,11 +239,11 @@ void mlir::configureOpenMPToLLVMConversionLegality(
   target.addDynamicallyLegalOp<
       mlir::omp::AtomicReadOp, mlir::omp::AtomicWriteOp, mlir::omp::FlushOp,
       mlir::omp::ThreadprivateOp, mlir::omp::YieldOp, mlir::omp::EnterDataOp,
-      mlir::omp::ExitDataOp, mlir::omp::DataBoundsOp, mlir::omp::MapInfoOp>(
-      [&](Operation *op) {
-        return typeConverter.isLegal(op->getOperandTypes()) &&
-               typeConverter.isLegal(op->getResultTypes());
-      });
+      mlir::omp::ExitDataOp, mlir::omp::UpdateDataOp, mlir::omp::DataBoundsOp,
+      mlir::omp::MapInfoOp>([&](Operation *op) {
+    return typeConverter.isLegal(op->getOperandTypes()) &&
+           typeConverter.isLegal(op->getResultTypes());
+  });
   target.addDynamicallyLegalOp<mlir::omp::ReductionOp>([&](Operation *op) {
     return typeConverter.isLegal(op->getOperandTypes());
   });
@@ -282,6 +282,7 @@ void mlir::populateOpenMPToLLVMConversionPatterns(LLVMTypeConverter &converter,
       RegionLessOpConversion<omp::YieldOp>,
       RegionLessOpConversion<omp::EnterDataOp>,
       RegionLessOpConversion<omp::ExitDataOp>,
+      RegionLessOpConversion<omp::UpdateDataOp>,
       RegionLessOpWithVarOperandsConversion<omp::DataBoundsOp>>(converter);
 }
 

openmp/libomptarget/test/offloading/fortran/target_update.f90

@@ -0,0 +1,50 @@
+! Offloading test for the `target update` directive.
+
+! REQUIRES: flang, amdgcn-amd-amdhsa
+
+! RUN: %libomptarget-compile-fortran-run-and-check-generic
+program target_update
+    implicit none
+    integer :: x(1)
+    integer :: host_id
+    integer :: device_id(1)
+
+    INTERFACE
+        FUNCTION omp_get_device_num() BIND(C)
+            USE, INTRINSIC :: iso_c_binding, ONLY: C_INT
+            integer :: omp_get_device_num
+        END FUNCTION omp_get_device_num
+    END INTERFACE
+
+    x(1) = 5
+    host_id = omp_get_device_num()
+
+!$omp target enter data map(to:x, device_id)
+!$omp target
+    x(1) = 42
+!$omp end target
+
+    ! Test that without a `target update` directive, the target update to x is
+    ! not yet seen by the host.
+    ! CHECK: After first target regions and before target update: x = 5
+    print *, "After first target regions and before target update: x =", x(1)
+
+!$omp target
+    x(1) = 84
+    device_id(1) = omp_get_device_num()
+!$omp end target
+!$omp target update from(x, device_id)
+
+    ! Test that after the `target update`, the host can see the new x value.
+    ! CHECK: After second target regions and target update: x = 84
+    print *, "After second target regions and target update: x =", x(1)
+
+    ! Make sure that offloading to the device actually happened. This way we
+    ! verify that we didn't take the fallback host execution path.
+    ! CHECK: Offloading succeeded!
+    if (host_id /= device_id(1)) then
+        print *, "Offloading succeeded!"
+    else
+        print *, "Offloading failed!"
+    end if
+end program target_update