basic-block.h (CLEANUP_PRE_LOOP): New.

	* basic-block.h (CLEANUP_PRE_LOOP): New.
	* except.c (finish_eh_generation): Update call of cleanup_cfg.
	* sibcall.c (optimize_sibling_calls): Likewise.
	* toplev.c (rest_of_compilation): Likewise.
	* flow.c (try_forward_edges): Take argument MODE;
	do not forward over loop pre-headers if CLEANUP_PRE_LOOP.
	(try_optimize_cfg): Update call of try_forward_edges.


	* (validate_replace_rtx_1): Fix simplification of MINUS.

From-SVN: r44458

7 files changed, 58 insertions, 16 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4a0fdff..aa26118 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+Sun Jul 29 18:59:13 CEST 2001  Jan Hubicka  <jh@suse.cz>
+
+	* basic-block.h (CLEANUP_PRE_LOOP): New.
+	* except.c (finish_eh_generation): Update call of cleanup_cfg.
+	* sibcall.c (optimize_sibling_calls): Likewise.
+	* toplev.c (rest_of_compilation): Likewise.
+	* flow.c (try_forward_edges): Take argument MODE;
+	do not forward over loop pre-headers if CLEANUP_PRE_LOOP.
+	(try_optimize_cfg): Update call of try_forward_edges.
+
+Sun Jul 29 18:59:56 CEST 2001  Roman Zippel  <zippel@linux-m68k.org>
+			       Jan Hubicka  <jh@suse.cz>
+
+	* (validate_replace_rtx_1): Fix simplification of MINUS.
+
 2001-07-29  Neil Booth  <neil@daikokuya.demon.co.uk>
 
 	PR preprocessor/3669
diff --git a/gcc/basic-block.h b/gcc/basic-block.h
index bddba84..7b467c2 100644
--- a/gcc/basic-block.h
+++ b/gcc/basic-block.h
@@ -551,6 +551,8 @@ enum update_life_extent
 					   to care REG_DEAD notes.  */
 #define CLEANUP_PRE_SIBCALL	8	/* Do not get confused by code hidden
 					   inside call_placeholders..  */
+#define CLEANUP_PRE_LOOP	16	/* Take care to preserve syntactic loop
+					   notes.  */
 /* Flags for loop discovery.  */
 
 #define LOOP_TREE		1 	/* Build loop hierarchy tree.  */
diff --git a/gcc/except.c b/gcc/except.c
index b45237c..49df0df 100644
--- a/gcc/except.c
+++ b/gcc/except.c
@@ -2348,7 +2348,7 @@ finish_eh_generation ()
 
   rebuild_jump_labels (get_insns ());
   find_basic_blocks (get_insns (), max_reg_num (), 0);
-  cleanup_cfg (0);
+  cleanup_cfg (CLEANUP_PRE_LOOP);
 
   /* These registers are used by the landing pads.  Make sure they
      have been generated.  */
@@ -2371,7 +2371,7 @@ finish_eh_generation ()
   find_exception_handler_labels ();
   rebuild_jump_labels (get_insns ());
   find_basic_blocks (get_insns (), max_reg_num (), 0);
-  cleanup_cfg (0);
+  cleanup_cfg (CLEANUP_PRE_LOOP);
 }
 
 /* This section handles removing dead code for flow.  */
diff --git a/gcc/flow.c b/gcc/flow.c
index 0fd58c0..992cac6 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -396,7 +396,7 @@ static bool try_optimize_cfg		PARAMS ((int));
 static bool can_fallthru		PARAMS ((basic_block, basic_block));
 static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block));
 static bool try_simplify_condjump	PARAMS ((basic_block));
-static bool try_forward_edges		PARAMS ((basic_block));
+static bool try_forward_edges		PARAMS ((int, basic_block));
 static void tidy_fallthru_edges		PARAMS ((void));
 static int verify_wide_reg_1		PARAMS ((rtx *, void *));
 static void verify_wide_reg		PARAMS ((int, rtx, rtx));
@@ -3182,8 +3182,9 @@ try_simplify_condjump (cbranch_block)
    Return true if sucessful.  */
 
 static bool
-try_forward_edges (b)
+try_forward_edges (mode, b)
      basic_block b;
+     int mode;
 {
   bool changed = false;
   edge e, next;
@@ -3216,6 +3217,30 @@ try_forward_edges (b)
 	  /* Bypass trivial infinite loops.  */
 	  if (target == target->succ->dest)
 	    counter = n_basic_blocks;
+
+	  /* Avoid killing of loop pre-headers, as it is the place loop
+	     optimizer wants to hoist code to.
+	 
+	     For fallthru forwarders, the LOOP_BEG note must appear between
+	     the header of block and CODE_LABEL of the loop, for non forwarders
+	     it must appear before the JUMP_INSN.  */
+	  if (mode & CLEANUP_PRE_LOOP)
+	    {
+	      rtx insn = (target->succ->flags & EDGE_FALLTHRU 
+		          ? target->head : prev_nonnote_insn (target->end));
+
+	      if (GET_CODE (insn) != NOTE)
+		insn = NEXT_INSN (insn);
+
+	      for (;insn && GET_CODE (insn) != CODE_LABEL && !INSN_P (insn);
+		   insn = NEXT_INSN (insn))
+		if (GET_CODE (insn) == NOTE
+		    && NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
+		  break;
+
+	      if (GET_CODE (insn) == NOTE)
+		break;
+	    }
 	  target = target->succ->dest, counter++;
 	}
 
@@ -3953,7 +3978,7 @@ try_optimize_cfg (mode)
 	    changed_here = true;
 
 	  /* Simplify branch to branch.  */
-	  if (try_forward_edges (b))
+	  if (try_forward_edges (mode, b))
 	    changed_here = true;
 
 	  /* Look for shared code between blocks.  */
diff --git a/gcc/recog.c b/gcc/recog.c
index c77bc42..fc349dd 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -521,8 +521,8 @@ validate_replace_rtx_1 (loc, from, to, object)
 			 simplify_gen_binary
 			 (PLUS, GET_MODE (x), XEXP (x, 0),
 			  simplify_gen_unary (NEG,
-					      op0_mode, XEXP (x, 1),
-					      op0_mode)), 1);
+					      GET_MODE (x), XEXP (x, 1),
+					      GET_MODE (x))), 1);
       break;
     case ZERO_EXTEND:
     case SIGN_EXTEND:
diff --git a/gcc/sibcall.c b/gcc/sibcall.c
index 1203e68..1e3be76 100644
--- a/gcc/sibcall.c
+++ b/gcc/sibcall.c
@@ -569,7 +569,7 @@ optimize_sibling_and_tail_recursive_calls ()
   /* We need cfg information to determine which blocks are succeeded
      only by the epilogue.  */
   find_basic_blocks (insns, max_reg_num (), 0);
-  cleanup_cfg (CLEANUP_PRE_SIBCALL);
+  cleanup_cfg (CLEANUP_PRE_SIBCALL | CLEANUP_PRE_LOOP);
 
   /* If there are no basic blocks, then there is nothing to do.  */
   if (n_basic_blocks == 0)
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 21d4fbb..07de29b 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -2737,7 +2737,7 @@ rest_of_compilation (decl)
 	      rebuild_jump_labels (insns);
 	      find_exception_handler_labels ();
 	      find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-	      cleanup_cfg (CLEANUP_PRE_SIBCALL);
+	      cleanup_cfg (CLEANUP_PRE_SIBCALL | CLEANUP_PRE_LOOP);
 	      optimize = saved_optimize;
 	    }
 
@@ -2846,7 +2846,7 @@ rest_of_compilation (decl)
   reg_scan (insns, max_reg_num (), 0);
   rebuild_jump_labels (insns);
   find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-  cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
+  cleanup_cfg ((optimize ? CLEANUP_EXPENSIVE : 0) | CLEANUP_PRE_LOOP);
   copy_loop_headers (insns);
   purge_line_number_notes (insns);
 
@@ -2870,7 +2870,7 @@ rest_of_compilation (decl)
       open_dump_file (DFI_ssa, decl);
 
       find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-      cleanup_cfg (CLEANUP_EXPENSIVE);
+      cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
       convert_to_ssa ();
 
       close_dump_file (DFI_ssa, print_rtl_with_bb, insns);
@@ -2935,7 +2935,7 @@ rest_of_compilation (decl)
   if (optimize > 0)
     {
       find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-      cleanup_cfg (CLEANUP_EXPENSIVE);
+      cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
 
       /* ??? Run if-conversion before delete_null_pointer_checks,
          since the later does not preserve the CFG.  This should
@@ -2992,7 +2992,7 @@ rest_of_compilation (decl)
 	  timevar_push (TV_JUMP);
 	  rebuild_jump_labels (insns);
 	  find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-	  cleanup_cfg (CLEANUP_EXPENSIVE);
+	  cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
 	  timevar_pop (TV_JUMP);
 	}
 
@@ -3006,7 +3006,7 @@ rest_of_compilation (decl)
 	  timevar_push (TV_JUMP);
 	  find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
 
-	  cleanup_cfg (CLEANUP_EXPENSIVE);
+	  cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
 
 	  delete_null_pointer_checks (insns);
 	  timevar_pop (TV_JUMP);
@@ -3040,7 +3040,7 @@ rest_of_compilation (decl)
       open_dump_file (DFI_gcse, decl);
 
       find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-      cleanup_cfg (CLEANUP_EXPENSIVE);
+      cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
       tem = gcse_main (insns, rtl_dump_file);
 
       save_csb = flag_cse_skip_blocks;
@@ -3067,7 +3067,7 @@ rest_of_compilation (decl)
 	  rebuild_jump_labels (insns);
 	  delete_trivially_dead_insns (insns, max_reg_num (), 0);
 	  find_basic_blocks (insns, max_reg_num (), rtl_dump_file);
-	  cleanup_cfg (CLEANUP_EXPENSIVE);
+	  cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_PRE_LOOP);
 	  timevar_pop (TV_JUMP);
 
 	  if (flag_expensive_optimizations)