extend.texi (flatten attribute): Remove note about unit-at-a-time

	* doc/extend.texi (flatten attribute): Remove note about unit-at-a-time
	* doc/invoke.texi (--combine): Likewise.
	(-finline-functions-called-once): Update levels when enabled.
	(-funit-at-a-time): Document new behaviour.
	(-ftoplevel-reorder): Document that it is enabled -O0 and imply
	-fno-section-anchors when disabled explicitly.
	(inline params): They are not ignored now.
	(precompiled headers): Remove unit-at-a-time as being incompatible.
	* opts.c (decode_options): Handle unit-at-a-time as alias;
	imply -fno-section-anchors when toplevel reorder is disabled
	explicitly.
	* common.opt (ftoplevel-reorder): Set default value to 2.
	(funit-at-a-time): Set default value to 1.
	* config/rs6000/rs6000.c (optimization_options): Set section anchors
	to 2.

From-SVN: r138009

1 files changed, 18 insertions, 5 deletions

diff --git a/gcc/opts.c b/gcc/opts.c
index 7e8e96c..0533c9fa 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -849,15 +849,28 @@ decode_options (unsigned int argc, const char **argv)
 	}
     }
 
-  if (!optimize)
+
+  if (!flag_unit_at_a_time)
     {
-      flag_merge_constants = 0;
+      flag_section_anchors = 0;
+      flag_toplevel_reorder = 0;
+      flag_unit_at_a_time = 1;
+    }
+  if (!flag_toplevel_reorder)
+    {
+      if (flag_section_anchors == 1)
+        error ("Section anchors must be disabled when toplevel reorder is disabled.");
+      flag_section_anchors = 0;
     }
 
-  if (!no_unit_at_a_time_default)
+  if (!optimize)
     {
-      flag_unit_at_a_time = 1;
-      if (!optimize)
+      flag_merge_constants = 0;
+
+      /* We disable toplevel reordering at -O0 to disable transformations that
+         might be surprising to end users and to get -fno-toplevel-reorder
+	 tested, but we keep section anchors.  */
+      if (flag_toplevel_reorder == 2)
         flag_toplevel_reorder = 0;
     }