This patch unsets -freorder-blocks-and-partition when -fprofile-use is not specified.

This patch unsets -freorder-blocks-and-partition when -fprofile-use
is not specified. Function splitting was not actually being performed
in that case, as probably_never_executed_bb_p does not distinguish
any basic blocks as being cold vs hot when there is no profile data.
Leaving it enabled, however, causes the assembly code generator to create
(empty) cold sections and labels, leading to unnecessary size overhead.

2015-09-25  Teresa Johnson  <tejohnson@google.com>

	* opts.c (finish_options): Unset -freorder-blocks-and-partition
	if not using profile.

From-SVN: r228136

gcc/ChangeLog

+2015-09-25  Teresa Johnson  <tejohnson@google.com>
+
+	* opts.c (finish_options): Unset -freorder-blocks-and-partition
+	if not using profile.
+
 2015-09-25  Manuel López-Ibáñez  <manu@gcc.gnu.org>
 
 	PR pretty-print/67567

gcc/opts.c

@@ -821,6 +821,16 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
       opts->x_flag_reorder_blocks = 1;
     }
 
+  /* Disable -freorder-blocks-and-partition when -fprofile-use is not in
+     effect. Function splitting was not actually being performed in that case,
+     as probably_never_executed_bb_p does not distinguish any basic blocks as
+     being cold vs hot when there is no profile data. Leaving it enabled,
+     however, causes the assembly code generator to create (empty) cold
+     sections and labels, leading to unnecessary size overhead.  */
+  if (opts->x_flag_reorder_blocks_and_partition
+      && !opts_set->x_flag_profile_use)
+    opts->x_flag_reorder_blocks_and_partition = 0;
+
   if (opts->x_flag_reorder_blocks_and_partition
       && !opts_set->x_flag_reorder_functions)
     opts->x_flag_reorder_functions = 1;