basic-block.h (CLEANUP_PRE_SIBCALL): New constant.

	* basic-block.h (CLEANUP_PRE_SIBCALL): New constant.
	* except.c (finish_eh_generation): Update call of cleanup_cfg;
	do rebuild_jump_labels instead of jump_optimize
	* sibcall.c (optimize_sibling_and_tail_recursive_call): Likewise.
	* toplev.c (rest_of_compulation): Likewise for -Wreturn_type.
	* flow.c (try_optimize_cfg): Remove unneeded code_labels.

	* flow.c: Include timevar.h
	(find_basic_block): Push/pop timevar;
	(cleanup_cfg): Likewise.
	* timevar.def (TV_CFG, TV_CLEANUP_CFG): New.
	* Makefile: Add dependencies on timevar.h

	* integrate.c (save_for_inline): Kill all BASIC_BLOCK notes.
	(copy_insn_list): Avoid killing of BASIC_BLOCK notes.

	* rtl.h (delete_trivially_dead_insns): Add new parameter.
	* toplev.c (rest_of_compilation): Update calls.
	* cse.c (set_live_p, insn_live_p, dead_libcall_p): Break out from ...
	(delete_trivially_dead_insns): ... here; accept new argument
	preserve_basic_blocks; preserve basic blocks if set.

	* reg-stack.c (stack_regs_mentioned): Return 0 if
	stack_regs_mentioned_data is not initialized.
	(reg_to_stack): Make stack_regs_mentioned survive after the
	reg-stack is completted; do not call cleanup_cfg.
	* toplev.c (rest_of_compilation): Do cleanup_cfg before bb-reorder;
	make cleanup_cfg after bb-reorder to output to debug file.

From-SVN: r44056

1 files changed, 33 insertions, 0 deletions

diff --git a/gcc/flow.c b/gcc/flow.c
index 6d25582..a771ab4 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -135,6 +135,7 @@ Boston, MA 02111-1307, USA.  */
 #include "recog.h"
 #include "expr.h"
 #include "ssa.h"
+#include "timevar.h"
 
 #include "obstack.h"
 #include "splay-tree.h"
@@ -499,6 +500,7 @@ find_basic_blocks (f, nregs, file)
      FILE *file ATTRIBUTE_UNUSED;
 {
   int max_uid;
+  timevar_push (TV_CFG);
 
   /* Flush out existing data.  */
   if (basic_block_info != NULL)
@@ -556,6 +558,7 @@ find_basic_blocks (f, nregs, file)
 #ifdef ENABLE_CHECKING
   verify_flow_info ();
 #endif
+  timevar_pop (TV_CFG);
 }
 
 void
@@ -1002,6 +1005,7 @@ void
 cleanup_cfg (mode)
      int mode;
 {
+  timevar_push (TV_CLEANUP_CFG);
   delete_unreachable_blocks ();
   if (try_optimize_cfg (mode))
     delete_unreachable_blocks ();
@@ -1010,6 +1014,7 @@ cleanup_cfg (mode)
   /* Kill the data we won't maintain.  */
   free_EXPR_LIST_list (&label_value_list);
   free_EXPR_LIST_list (&tail_recursion_label_list);
+  timevar_pop (TV_CLEANUP_CFG);
 }
 
 /* Create a new basic block consisting of the instructions between
@@ -2960,6 +2965,14 @@ merge_blocks (e, b, c, mode)
       int c_has_outgoing_fallthru;
       int b_has_incoming_fallthru;
 
+      /* Avoid overactive code motion, as the forwarder blocks should eb
+         eliminated by the edge redirection instead. Only exception is the
+	 case b is an forwarder block and c has no fallthru edge, but no
+	 optimizers should be confused by this extra jump and we are about
+	 to kill the jump in bb_reorder pass instead.  */
+      if (forwarder_block_p (b) || forwarder_block_p (c))
+	return 0;
+
       /* We must make sure to not munge nesting of exception regions,
 	 lexical blocks, and loop notes.
 
@@ -3688,6 +3701,26 @@ try_optimize_cfg (mode)
 	      b = c;
 	    }
 
+	  /* Remove code labels no longer used.  
+	     Don't do the optimization before sibling calls are discovered,
+	     as some branches may be hidden inside CALL_PLACEHOLDERs.  */
+	  if (!(mode & CLEANUP_PRE_SIBCALL)
+	      && b->pred->pred_next == NULL
+	      && (b->pred->flags & EDGE_FALLTHRU)
+	      && GET_CODE (b->head) == CODE_LABEL
+	      /* If previous block does end with condjump jumping to next BB,
+	         we can't delete the label.  */
+	      && (b->pred->src == ENTRY_BLOCK_PTR
+		  || !reg_mentioned_p (b->head, b->pred->src->end)))
+	    {
+	      rtx label = b->head;
+	      b->head = NEXT_INSN (b->head);
+	      flow_delete_insn_chain (label, label);
+	      if (rtl_dump_file)
+		fprintf (rtl_dump_file, "Deleted label in block %i.\n",
+			 b->index);
+	    }
+
 	  /* A loop because chains of blocks might be combineable.  */
 	  while ((s = b->succ) != NULL
 		 && s->succ_next == NULL