[gcc/devel/omp/gcc-12] libgomp: no need to attach USM pointers

[gcc/devel/omp/gcc-12] libgomp: no need to attach USM pointers

[Andrew Stubbs]

https://gcc.gnu.org/g:3ad47717bf7163ed1628c829e06166a74c1e9cd3

commit 3ad47717bf7163ed1628c829e06166a74c1e9cd3
Author: Andrew Stubbs <ams@codesourcery.com>
Date:   Mon Feb 20 12:23:14 2023 +0000

    libgomp: no need to attach USM pointers
    
    Fix a bug in which Fortran pointers inside derived types caused a runtime
    error when Unified Shared Memory was active.
    
    libgomp/ChangeLog:
    
            * target.c (gomp_attach_pointer): Check for USM.
            * testsuite/libgomp.fortran/usm-3.f90: New test.

Diff:
---
 libgomp/ChangeLog.omp                       |  5 +++++
 libgomp/target.c                            |  5 +++++
 libgomp/testsuite/libgomp.fortran/usm-3.f90 | 33 +++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/libgomp/ChangeLog.omp b/libgomp/ChangeLog.omp
index 98f046c292a..51c15697e72 100644
--- a/libgomp/ChangeLog.omp
+++ b/libgomp/ChangeLog.omp
@@ -1,3 +1,8 @@
+2023-02-23  Andrew Stubbs  <ams@codesourcery.com>
+
+	* target.c (gomp_attach_pointer): Check for USM.
+	* testsuite/libgomp.fortran/usm-3.f90: New test.
+
 2023-02-22  Tobias Burnus  <tobias@codesourcery.com>
 
 	* testsuite/libgomp.fortran/target-enter-data-3.f90: Uncomment
diff --git a/libgomp/target.c b/libgomp/target.c
index 24109f28ddc..fcc5b9dabca 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -836,6 +836,11 @@ gomp_attach_pointer (struct gomp_device_descr *devicep,
 	  gomp_fatal ("attempt to attach null pointer");
 	}
 
+      if (devicep->is_usm_ptr_func
+	  && devicep->is_usm_ptr_func ((void*)(target + bias)))
+	/* Nothing to do here.  */
+	return;
+
       s.host_start = target + bias;
       s.host_end = s.host_start + 1;
       tn = splay_tree_lookup (mem_map, &s);
diff --git a/libgomp/testsuite/libgomp.fortran/usm-3.f90 b/libgomp/testsuite/libgomp.fortran/usm-3.f90
new file mode 100644
index 00000000000..ff15f4ba1f5
--- /dev/null
+++ b/libgomp/testsuite/libgomp.fortran/usm-3.f90
@@ -0,0 +1,33 @@
+! { dg-do run }
+! { dg-require-effective-target omp_usm }
+
+! Ensure that derived types containing allocated values work
+! with Unified Shared Memory.
+
+program usm
+!$omp requires unified_shared_memory
+  use iso_fortran_env
+  implicit none
+
+  type :: struct
+    real(real64), allocatable :: v(:)
+  end type struct
+
+  integer :: index
+  type(struct) :: s
+
+  real(real64), allocatable :: expected(:)
+
+  allocate(s%v(100))
+  do index = 1, size(s%v)
+    s%v(index) = index
+  end do
+  allocate(expected, mold=s%v)
+  expected = s%v - 1._real64
+
+  !$omp target
+  s%v = s%v - 1._real64
+  !$omp end target
+
+  if (any(s%v /= expected)) STOP 1
+end program usm