re PR tree-optimization/70602 (wrong code at -O1 and above on x86_64-linux-gnu…

re PR tree-optimization/70602 (wrong code at -O1 and above on x86_64-linux-gnu in 32-bit mode (and at -Os only in 64-bit mode))

	PR tree-optimization/70602
	* tree-sra.c (generate_subtree_copies): Don't write anything into
	constant pool decls.

	* gcc.c-torture/execute/pr70602.c: New test.

From-SVN: r234895

gcc/ChangeLog

 2016-04-12  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/70602
+	* tree-sra.c (generate_subtree_copies): Don't write anything into
+	constant pool decls.
+
 	* omp-low.c (lower_omp_target): Use GOMP_MAP_FIRSTPRIVATE_INT
 	regardless whether there are depend clauses or not.
 

gcc/testsuite/ChangeLog

+2016-04-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/70602
+	* gcc.c-torture/execute/pr70602.c: New test.
+
 2016-04-11  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	PR target/70381

gcc/testsuite/gcc.c-torture/execute/pr70602.c

+/* PR tree-optimization/70602 */
+
+struct __attribute__((packed)) S
+{
+  int s : 1;
+  int t : 20;
+};
+
+int a, b, c;
+
+int
+main ()
+{
+  for (; a < 1; a++)
+    {
+      struct S e[] = { {0, 9}, {0, 9}, {0, 9}, {0, 0}, {0, 9}, {0, 9}, {0, 9}, 
+		       {0, 0}, {0, 9}, {0, 9}, {0, 9}, {0, 0}, {0, 9}, {0, 9}, 
+		       {0, 9}, {0, 0}, {0, 9}, {0, 9}, {0, 9}, {0, 0}, {0, 9} };
+      b = b || e[0].s;
+      c = e[0].t;
+    }
+  return 0;
+}

gcc/tree-sra.c

@@ -2743,6 +2743,9 @@ generate_subtree_copies (struct access *access, tree agg,
 			 gimple_stmt_iterator *gsi, bool write,
 			 bool insert_after, location_t loc)
 {
+  /* Never write anything into constant pool decls.  See PR70602.  */
+  if (!write && constant_decl_p (agg))
+    return;
   do
     {
       if (chunk_size && access->offset >= start_offset + chunk_size)