re PR middle-end/48770 (wrong code with -O -fprofile-arcs -fPIC -fno-dce -fno-forward-propagate -fno-tree-forwprop)

	PR middle-end/48770
	* reload.h (reload): Change to return a bool.
	* ira.c (ira): If requested by reload, run a fast DCE pass after
	reload has completed.  Fix comment typo.
	* reload1.c (need_dce): New file scoped static.
	(reload): Set reload_completed here.  Return whether or not a DCE
	pass after reload is needed.
	(delete_dead_insn): Set need_dce as needed.

	PR middle-end/48770
	* gcc.dg/pr48770.c: New test.

From-SVN: r175353

1 files changed, 7 insertions, 2 deletions

diff --git a/gcc/ira.c b/gcc/ira.c
index 5cfe5c0..6cca908 100644
--- a/gcc/ira.c
+++ b/gcc/ira.c
@@ -383,6 +383,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "integrate.h"
 #include "ggc.h"
 #include "ira-int.h"
+#include "dce.h"
 
 
 struct target_ira default_target_ira;
@@ -3526,6 +3527,7 @@ ira (FILE *f)
   int rebuild_p;
   int saved_flag_ira_share_spill_slots;
   basic_block bb;
+  bool need_dce;
 
   timevar_push (TV_IRA);
 
@@ -3717,7 +3719,7 @@ ira (FILE *f)
   df_set_flags (DF_NO_INSN_RESCAN);
   build_insn_chain ();
 
-  reload_completed = !reload (get_insns (), ira_conflicts_p);
+  need_dce = reload (get_insns (), ira_conflicts_p);
 
   timevar_pop (TV_RELOAD);
 
@@ -3760,7 +3762,7 @@ ira (FILE *f)
 #endif
 
   /* The code after the reload has changed so much that at this point
-     we might as well just rescan everything.  Not that
+     we might as well just rescan everything.  Note that
      df_rescan_all_insns is not going to help here because it does not
      touch the artificial uses and defs.  */
   df_finish_pass (true);
@@ -3772,6 +3774,9 @@ ira (FILE *f)
   if (optimize)
     df_analyze ();
 
+  if (need_dce && optimize)
+    run_fast_dce ();
+
   timevar_pop (TV_IRA);
 }