sparc-common.c (sparc_option_optimization_table): Enable REE at -O2 and higher.

	* common/config/sparc/sparc-common.c (sparc_option_optimization_table):
	Enable REE at -O2 and higher.
	* config/sparc/sparc.c (sparc_option_override): Disable it by default
	in 32-bit mode.

From-SVN: r242841

gcc/ChangeLog

+2016-11-24  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* common/config/sparc/sparc-common.c (sparc_option_optimization_table):
+	Enable REE at -O2 and higher.
+	* config/sparc/sparc.c (sparc_option_override): Disable it by default
+	in 32-bit mode.
+
 2016-11-24  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	PR target/48863

gcc/common/config/sparc/sparc-common.c

@@ -28,6 +28,8 @@ along with GCC; see the file COPYING3.  If not see
 static const struct default_options sparc_option_optimization_table[] =
   {
     { OPT_LEVELS_1_PLUS, OPT_fomit_frame_pointer, NULL, 1 },
+    /* Enable redundant extension instructions removal at -O2 and higher.  */
+    { OPT_LEVELS_2_PLUS, OPT_free, NULL, 1 },
     { OPT_LEVELS_NONE, 0, NULL, 0 }
   };
 

gcc/config/sparc/sparc.c

@@ -1713,6 +1713,11 @@ sparc_option_override (void)
      pessimizes for double floating-point registers.  */
   if (!global_options_set.x_flag_ira_share_save_slots)
     flag_ira_share_save_slots = 0;
+
+  /* Only enable REE by default in 64-bit mode where it helps to eliminate
+     redundant 32-to-64-bit extensions.  */
+  if (!global_options_set.x_flag_ree && TARGET_ARCH32)
+    flag_ree = 0;
 }
 
 /* Miscellaneous utilities.  */