nptx.c (nvptx_option_override): Only set flag_toplevel_reorder, if not explicitly specified.

	* config/nvptx/nptx.c (nvptx_option_override): Only set
	flag_toplevel_reorder, if not explicitly specified.  Set
	flag_no_common, unless explicitly specified.

	testsuite/
	* gcc.target/nvptx/uninit-decl.c: Force common storage,  add
	non-common cases.
	* gcc.dg/tree-ssa/ssa-store-ccp-2.c: Add -fcommon.

From-SVN: r236532

gcc/ChangeLog

+2016-05-20  Nathan Sidwell  <nathan@acm.org>
+
+	* config/nvptx/nptx.c (nvptx_option_override): Only set
+	flag_toplevel_reorder, if not explicitly specified.  Set
+	flag_no_common, unless explicitly specified.
+
 2016-05-20  David Malcolm  <dmalcolm@redhat.com>
 
 	* calls.c (can_implement_as_sibling_call_p): Mark param

gcc/config/nvptx/nvptx.c

@@ -155,8 +155,19 @@ static void
 nvptx_option_override (void)
 {
   init_machine_status = nvptx_init_machine_status;
-  /* Gives us a predictable order, which we need especially for variables.  */
-  flag_toplevel_reorder = 1;
+
+  /* Set toplevel_reorder, unless explicitly disabled.  We need
+     reordering so that we emit necessary assembler decls of
+     undeclared variables. */
+  if (!global_options_set.x_flag_toplevel_reorder)
+    flag_toplevel_reorder = 1;
+
+  /* Set flag_no_common, unless explicitly disabled.  We fake common
+     using .weak, and that's not entirely accurate, so avoid it
+     unless forced.  */
+  if (!global_options_set.x_flag_no_common)
+    flag_no_common = 1;
+
   /* Assumes that it will see only hard registers.  */
   flag_var_tracking = 0;
 

gcc/testsuite/gcc.dg/tree-ssa/ssa-store-ccp-2.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-options "-O2 -fdump-tree-optimized -fcommon" } */
 
 const int conststaticvariable;
 

gcc/testsuite/gcc.target/nvptx/uninit-decl.c

 /* { dg-do compile } */
 
-int __attribute__ ((used)) common;
-static int __attribute__ ((used)) local;
+int __attribute__ ((common)) common;
+static int local;
+extern int external_decl;
+int external_defn;
+
+int foo ()
+{
+  return common +  local + external_decl + external_defn;
+}
+
+void bar (int i)
+{
+  common = local = external_decl = external_defn = i;
+}
 
 /* { dg-final { scan-assembler "\[\n\r\]\[\t \]*.weak .global\[^,\n\r\]*common" } } */
 /* { dg-final { scan-assembler "\[\n\r\]\[\t \]*.global\[^,\n\r\]*local" } } */
+/* { dg-final { scan-assembler "\[\n\r\]\[\t \]*.extern .global\[^,\n\r\]*external_decl" } } */
+/* { dg-final { scan-assembler "\[\n\r\]\[\t \]*.visible .global\[^,\n\r\]*external_defn" } } */