tree-nested: Fix handling of *reduction clauses with C array sections [PR93566]

tree-nested.c didn't handle C array sections in {,task_,in_}reduction clauses.

2020-03-14  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/93566
	* tree-nested.c (convert_nonlocal_omp_clauses,
	convert_local_omp_clauses): Handle {,in_,task_}reduction clauses
	with C/C++ array sections.

	* testsuite/libgomp.c/pr93566.c: New test.

4 files changed, 155 insertions, 7 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 91e9467..883e13f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/93566
+	* tree-nested.c (convert_nonlocal_omp_clauses,
+	convert_local_omp_clauses): Handle {,in_,task_}reduction clauses
+	with C/C++ array sections.
+
 2020-03-14  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/89229
diff --git a/gcc/tree-nested.c b/gcc/tree-nested.c
index 2bb1106..6f696da 100644
--- a/gcc/tree-nested.c
+++ b/gcc/tree-nested.c
@@ -1188,7 +1188,7 @@ convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 {
   struct nesting_info *const info = (struct nesting_info *) wi->info;
   bool need_chain = false, need_stmts = false;
-  tree clause, decl;
+  tree clause, decl, *pdecl;
   int dummy;
   bitmap new_suppress;
 
@@ -1197,6 +1197,7 @@ convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 
   for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
     {
+      pdecl = NULL;
       switch (OMP_CLAUSE_CODE (clause))
 	{
 	case OMP_CLAUSE_REDUCTION:
@@ -1204,6 +1205,15 @@ convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 	case OMP_CLAUSE_TASK_REDUCTION:
 	  if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (clause))
 	    need_stmts = true;
+	  if (TREE_CODE (OMP_CLAUSE_DECL (clause)) == MEM_REF)
+	    {
+	      pdecl = &TREE_OPERAND (OMP_CLAUSE_DECL (clause), 0);
+	      if (TREE_CODE (*pdecl) == POINTER_PLUS_EXPR)
+		pdecl = &TREE_OPERAND (*pdecl, 0);
+	      if (TREE_CODE (*pdecl) == INDIRECT_REF
+		  || TREE_CODE (*pdecl) == ADDR_EXPR)
+		pdecl = &TREE_OPERAND (*pdecl, 0);
+	    }
 	  goto do_decl_clause;
 
 	case OMP_CLAUSE_LASTPRIVATE:
@@ -1230,7 +1240,9 @@ convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 	case OMP_CLAUSE_USE_DEVICE_ADDR:
 	case OMP_CLAUSE_IS_DEVICE_PTR:
 	do_decl_clause:
-	  decl = OMP_CLAUSE_DECL (clause);
+	  if (pdecl == NULL)
+	    pdecl = &OMP_CLAUSE_DECL (clause);
+	  decl = *pdecl;
 	  if (VAR_P (decl)
 	      && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
 	    break;
@@ -1239,7 +1251,7 @@ convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 	      if (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_SHARED)
 		OMP_CLAUSE_SHARED_READONLY (clause) = 0;
 	      bitmap_set_bit (new_suppress, DECL_UID (decl));
-	      OMP_CLAUSE_DECL (clause) = get_nonlocal_debug_decl (info, decl);
+	      *pdecl = get_nonlocal_debug_decl (info, decl);
 	      if (OMP_CLAUSE_CODE (clause) != OMP_CLAUSE_PRIVATE)
 		need_chain = true;
 	    }
@@ -1909,7 +1921,7 @@ convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 {
   struct nesting_info *const info = (struct nesting_info *) wi->info;
   bool need_frame = false, need_stmts = false;
-  tree clause, decl;
+  tree clause, decl, *pdecl;
   int dummy;
   bitmap new_suppress;
 
@@ -1918,6 +1930,7 @@ convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 
   for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
     {
+      pdecl = NULL;
       switch (OMP_CLAUSE_CODE (clause))
 	{
 	case OMP_CLAUSE_REDUCTION:
@@ -1925,6 +1938,15 @@ convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 	case OMP_CLAUSE_TASK_REDUCTION:
 	  if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (clause))
 	    need_stmts = true;
+	  if (TREE_CODE (OMP_CLAUSE_DECL (clause)) == MEM_REF)
+	    {
+	      pdecl = &TREE_OPERAND (OMP_CLAUSE_DECL (clause), 0);
+	      if (TREE_CODE (*pdecl) == POINTER_PLUS_EXPR)
+		pdecl = &TREE_OPERAND (*pdecl, 0);
+	      if (TREE_CODE (*pdecl) == INDIRECT_REF
+		  || TREE_CODE (*pdecl) == ADDR_EXPR)
+		pdecl = &TREE_OPERAND (*pdecl, 0);
+	    }
 	  goto do_decl_clause;
 
 	case OMP_CLAUSE_LASTPRIVATE:
@@ -1951,7 +1973,9 @@ convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 	case OMP_CLAUSE_USE_DEVICE_ADDR:
 	case OMP_CLAUSE_IS_DEVICE_PTR:
 	do_decl_clause:
-	  decl = OMP_CLAUSE_DECL (clause);
+	  if (pdecl == NULL)
+	    pdecl = &OMP_CLAUSE_DECL (clause);
+	  decl = *pdecl;
 	  if (VAR_P (decl)
 	      && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
 	    break;
@@ -1964,8 +1988,7 @@ convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
 		  if (OMP_CLAUSE_CODE (clause) == OMP_CLAUSE_SHARED)
 		    OMP_CLAUSE_SHARED_READONLY (clause) = 0;
 		  bitmap_set_bit (new_suppress, DECL_UID (decl));
-		  OMP_CLAUSE_DECL (clause)
-		    = get_local_debug_decl (info, decl, field);
+		  *pdecl = get_local_debug_decl (info, decl, field);
 		  need_frame = true;
 		}
 	    }
diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog
index bff3ae5..5882c8a 100644
--- a/libgomp/ChangeLog
+++ b/libgomp/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/93566
+	* testsuite/libgomp.c/pr93566.c: New test.
+
 2020-02-21  Frederik Harwath  <frederik@codesourcery.com>
 
 	* testsuite/libgomp.oacc-fortran/acc_get_property.f90: Adapt to
diff --git a/libgomp/testsuite/libgomp.c/pr93566.c b/libgomp/testsuite/libgomp.c/pr93566.c
new file mode 100644
index 0000000..3334bd57
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c/pr93566.c
@@ -0,0 +1,113 @@
+/* PR middle-end/93566 */
+/* { dg-additional-options "-std=c99" } */
+
+extern void abort (void);
+
+void
+foo (int *x)
+{
+  void nest (void) {
+    #pragma omp parallel for reduction(+:x[:10])
+    for (int i = 0; i < 1024; i++)
+      for (int j = 0; j < 10; j++)
+	x[j] += j * i;
+  }
+  nest ();
+  for (int i = 0; i < 10; i++)
+    if (x[i] != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+void
+bar (void)
+{
+  int x[10] = {};
+  void nest (void) {
+    #pragma omp parallel for reduction(+:x[:10])
+    for (int i = 0; i < 1024; i++)
+      for (int j = 0; j < 10; j++)
+	x[j] += j * i;
+  }
+  nest ();
+  for (int i = 0; i < 10; i++)
+    if (x[i] != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+void
+baz (void)
+{
+  int x[10] = {};
+  void nest (void) {
+    #pragma omp parallel for reduction(+:x[2:5])
+    for (int i = 0; i < 1024; i++)
+      for (int j = 2; j < 7; j++)
+	x[j] += j * i;
+  }
+  nest ();
+  for (int i = 2; i < 7; i++)
+    if (x[i] != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+void
+qux (int *x)
+{
+  void nest (void) { x++; }
+  nest ();
+  #pragma omp parallel for reduction(+:x[:9])
+  for (int i = 0; i < 1024; i++)
+    for (int j = 0; j < 9; j++)
+      x[j] += j * i;
+  nest ();
+  for (int i = 0; i < 9; i++)
+    if (x[i - 1] != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+void
+quux (void)
+{
+  int x[10];
+  void nest (void) { for (int i = 0; i < 10; i++) x[i] = 0; }
+  int nest2 (int i) { return x[i]; }
+  nest ();
+  #pragma omp parallel for reduction(+:x[:7])
+  for (int i = 0; i < 1024; i++)
+    for (int j = 0; j < 7; j++)
+      x[j] += j * i;
+  for (int i = 0; i < 7; i++)
+    if (nest2 (i) != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+void
+corge (void)
+{
+  int x[10];
+  void nest (void) { for (int i = 0; i < 10; i++) x[i] = 0; }
+  int nest2 (int i) { return x[i]; }
+  nest ();
+  #pragma omp parallel for reduction(+:x[2:4])
+  for (int i = 0; i < 1024; i++)
+    for (int j = 2; j < 6; j++)
+      x[j] += j * i;
+  for (int i = 2; i < 6; i++)
+    if (nest2 (i) != 1023 * 1024 / 2 * i)
+      abort ();
+}
+
+int
+main ()
+{
+  int a[10] = {};
+  foo (a);
+  bar ();
+  baz ();
+  for (int i = 0; i < 10; i++)
+    a[i] = 0;
+  qux (a);
+  quux ();
+  corge ();
+  return 0;
+}