OpenACC: Fix reduction tree-sharing issue [PR106982]

The tree for var == incoming == outgound was
'MEM <double[5]> [(double *)&reduced]' which caused the ICE
"incorrect sharing of tree nodes".

	PR middle-end/106982

gcc/ChangeLog:

	* omp-low.cc (lower_oacc_reductions): Add some unshare_expr.

gcc/testsuite/ChangeLog:

	* c-c++-common/goacc/reduction-7.c: New test.
	* c-c++-common/goacc/reduction-8.c: New test.

diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index d9f9aaebc0b0572f3e92cbb93cde0e65d10cebc0..dc42c752017311ffeca934f94d40186b5352b783 100644 (file)
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -7631,6 +7631,7 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
              incoming = build_simple_mem_ref (incoming);
          }
        else
+         /* Note that 'var' might be a mem ref.  */
          v1 = v2 = v3 = var;
 
        /* Determine position in reduction buffer, which may be used
@@ -7659,26 +7660,28 @@ lower_oacc_reductions (location_t loc, tree clauses, tree level, bool inner,
          = build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
                                          TREE_TYPE (var), 6, setup_code,
                                          unshare_expr (ref_to_res),
-                                         incoming, level, op, off);
+                                         unshare_expr (incoming),
+                                         level, op, off);
        tree init_call
          = build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
                                          TREE_TYPE (var), 6, init_code,
                                          unshare_expr (ref_to_res),
-                                         v1, level, op, off);
+                                         unshare_expr (v1), level, op, off);
        tree fini_call
          = build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
                                          TREE_TYPE (var), 6, fini_code,
                                          unshare_expr (ref_to_res),
-                                         v2, level, op, off);
+                                         unshare_expr (v2), level, op, off);
        tree teardown_call
          = build_call_expr_internal_loc (loc, IFN_GOACC_REDUCTION,
                                          TREE_TYPE (var), 6, teardown_code,
-                                         ref_to_res, v3, level, op, off);
+                                         ref_to_res, unshare_expr (v3),
+                                         level, op, off);
 
-       gimplify_assign (v1, setup_call, &before_fork);
-       gimplify_assign (v2, init_call, &after_fork);
-       gimplify_assign (v3, fini_call, &before_join);
-       gimplify_assign (outgoing, teardown_call, &after_join);
+       gimplify_assign (unshare_expr (v1), setup_call, &before_fork);
+       gimplify_assign (unshare_expr (v2), init_call, &after_fork);
+       gimplify_assign (unshare_expr (v3), fini_call, &before_join);
+       gimplify_assign (unshare_expr (outgoing), teardown_call, &after_join);
       }
 
   /* Now stitch things together.  */

diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-7.c b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
new file mode 100644 (file)
index 0000000..482b0ab
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-7.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+long long n = 100;
+int multiplicitive_n = 128;
+
+void test1(double *rand, double *a, double *b, double *c)
+{
+#pragma acc data copyin(a[0:10*multiplicitive_n], b[0:10*multiplicitive_n]) copyout(c[0:10])
+    {
+#pragma acc parallel loop
+        for (int i = 0; i < 10; ++i)
+        {
+        double temp = 1.0;
+#pragma acc loop vector reduction(*:temp)
+        for (int j = 0; j < multiplicitive_n; ++j)
+          temp *= a[(i * multiplicitive_n) + j] + b[(i * multiplicitive_n) + j];
+        c[i] = temp;
+        }
+    }
+}

diff --git a/gcc/testsuite/c-c++-common/goacc/reduction-8.c b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
new file mode 100644 (file)
index 0000000..2c3ed49
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/goacc/reduction-8.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+/* PR middle-end/106982 */
+
+void test1(double *c)
+{
+    double reduced[5];
+#pragma acc parallel loop gang private(reduced)
+    for (int x = 0; x < 5; ++x)
+#pragma acc loop worker reduction(*:reduced)
+      for (int y = 0; y < 5; ++y) { }
+}