From: Chung-Lin Tang <cltang@codesourcery.com>
Date: Tue, 5 Apr 2022 15:31:34 +0000 (-0700)
Subject: OpenMP: Fix nested use_device_ptr
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=db43489efb81368fa5352d60072090e0ee0e6a04;p=thirdparty%2Fgcc.git

OpenMP: Fix nested use_device_ptr

This patch fixes a bug in lower_omp_target, where for Fortran arrays,
the expanded sender assignment is wrongly using the variable in the
current ctx, instead of the one looked-up outside, which is causing
use_device_ptr/addr to fail to work when used inside an omp-parallel
(where the omp child_fn is split away from the original).

The fix is inside omp-low.cc, though because the omp_array_data langhook
is used only by Fortran, this is essentially Fortran-specific.

2022-04-05  Chung-Lin Tang  <cltang@codesourcery.com>

gcc/ChangeLog:

	* omp-low.cc (lower_omp_target): Use outer context looked-up 'var' as
	argument to lang_hooks.decls.omp_array_data, instead of 'ovar' from
	current clause.

libgomp/ChangeLog:

	* testsuite/libgomp.fortran/use_device_ptr-4.f90: New testcase.

(cherry picked from commit b0af8e3a502a64a0e0a04cc54ef055e5d942240f)
---

diff --git a/gcc/omp-low.c b/gcc/omp-low.c
index 4e73a7a4085d..4653370aa418 100644
--- a/gcc/omp-low.c
+++ b/gcc/omp-low.c
@@ -14261,7 +14261,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx)
 
 	    type = TREE_TYPE (ovar);
 	    if (lang_hooks.decls.omp_array_data (ovar, true))
-	      var = lang_hooks.decls.omp_array_data (ovar, false);
+	      var = lang_hooks.decls.omp_array_data (var, false);
 	    else if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_USE_DEVICE_ADDR
 		      && !omp_is_reference (ovar)
 		      && !omp_is_allocatable_or_ptr (ovar))
diff --git a/libgomp/testsuite/libgomp.fortran/use_device_ptr-4.f90 b/libgomp/testsuite/libgomp.fortran/use_device_ptr-4.f90
new file mode 100644
index 000000000000..8c361d1e3cd9
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/use_device_ptr-4.f90
@@ -0,0 +1,41 @@
+! { dg-do run }
+!
+! Test user_device_ptr nested within another parallel
+! construct
+!
+program test_nested_use_device_ptr
+  use iso_c_binding, only: c_loc, c_ptr
+  implicit none
+  real, allocatable, target :: arr(:,:)
+  integer :: width = 1024, height = 1024, i
+  type(c_ptr) :: devptr
+
+  allocate(arr(width,height))
+
+  !$omp target enter data map(alloc: arr)
+
+  !$omp target data use_device_ptr(arr)
+  devptr = c_loc(arr(1,1))
+  !$omp end target data
+
+  !$omp parallel default(none) shared(arr, devptr)
+  !$omp single
+
+  !$omp target data use_device_ptr(arr)
+  call thing(c_loc(arr), devptr)
+  !$omp end target data
+
+  !$omp end single
+  !$omp end parallel
+  !$omp target exit data map(delete: arr)
+
+contains
+
+  subroutine thing(myarr, devptr)
+    use iso_c_binding, only: c_ptr, c_associated
+    implicit none
+    type(c_ptr) :: myarr, devptr
+    if (.not.c_associated(myarr, devptr)) stop 1
+  end subroutine thing
+
+end program