X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Ftree-ssa-loop-ch.c;h=ff62c686c2851d84189347cc11fe695690df05af;hp=2b3094622d71c8ffdb1a02aad9de300f35ff5a91;hb=f2852046a2c3bac1d4455e33876fc9991e9fc713;hpb=00bd8b4402db49aeb3edfbfd278b1566b02a9563

diff --git a/gcc/tree-ssa-loop-ch.c b/gcc/tree-ssa-loop-ch.c
index 2b3094622d7..ff62c686c28 100644
--- a/gcc/tree-ssa-loop-ch.c
+++ b/gcc/tree-ssa-loop-ch.c
@@ -1,11 +1,11 @@
 /* Loop header copying on trees.
-   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
    
 This file is part of GCC.
    
 GCC is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
-Free Software Foundation; either version 2, or (at your option) any
+Free Software Foundation; either version 3, or (at your option) any
 later version.
    
 GCC is distributed in the hope that it will be useful, but WITHOUT
@@ -14,9 +14,8 @@ FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 for more details.
    
 You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING.  If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA.  */
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
 
 #include "config.h"
 #include "system.h"
@@ -87,7 +86,7 @@ should_duplicate_loop_header_p (basic_block header, struct loop *loop,
       if (get_call_expr_in (last))
 	return false;
 
-      *limit -= estimate_num_insns (last);
+      *limit -= estimate_num_insns (last, &eni_size_weights);
       if (*limit < 0)
 	return false;
     }
@@ -120,11 +119,10 @@ do_while_loop_p (struct loop *loop)
    of the loop.  This is beneficial since it increases efficiency of
    code motion optimizations.  It also saves one jump on entry to the loop.  */
 
-static void
+static unsigned int
 copy_loop_headers (void)
 {
-  struct loops *loops;
-  unsigned i;
+  loop_iterator li;
   struct loop *loop;
   basic_block header;
   edge exit, entry;
@@ -132,30 +130,27 @@ copy_loop_headers (void)
   unsigned n_bbs;
   unsigned bbs_size;
 
-  loops = loop_optimizer_init (dump_file);
-  if (!loops)
-    return;
-  
-  /* We do not try to keep the information about irreducible regions
-     up-to-date.  */
-  loops->state &= ~LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS;
+  loop_optimizer_init (LOOPS_HAVE_PREHEADERS
+		       | LOOPS_HAVE_SIMPLE_LATCHES);
+  if (number_of_loops () <= 1)
+    {
+      loop_optimizer_finalize ();
+      return 0;
+    }
 
 #ifdef ENABLE_CHECKING
-  verify_loop_structure (loops);
+  verify_loop_structure ();
 #endif
 
-  bbs = xmalloc (sizeof (basic_block) * n_basic_blocks);
-  copied_bbs = xmalloc (sizeof (basic_block) * n_basic_blocks);
+  bbs = XNEWVEC (basic_block, n_basic_blocks);
+  copied_bbs = XNEWVEC (basic_block, n_basic_blocks);
   bbs_size = n_basic_blocks;
 
-  for (i = 1; i < loops->num; i++)
+  FOR_EACH_LOOP (li, loop, 0)
     {
       /* Copy at most 20 insns.  */
       int limit = 20;
 
-      loop = loops->parray[i];
-      if (!loop)
-	continue;
       header = loop->header;
 
       /* If the loop is already a do-while style one (either because it was
@@ -197,7 +192,7 @@ copy_loop_headers (void)
       /* Ensure that the header will have just the latch as a predecessor
 	 inside the loop.  */
       if (!single_pred_p (exit->dest))
-	exit = single_pred_edge (loop_split_edge_with (exit, NULL));
+	exit = single_pred_edge (split_edge (exit));
 
       entry = loop_preheader_edge (loop);
 
@@ -207,16 +202,49 @@ copy_loop_headers (void)
 	  continue;
 	}
 
+      /* If the loop has the form "for (i = j; i < j + 10; i++)" then
+	 this copying can introduce a case where we rely on undefined
+	 signed overflow to eliminate the preheader condition, because
+	 we assume that "j < j + 10" is true.  We don't want to warn
+	 about that case for -Wstrict-overflow, because in general we
+	 don't warn about overflow involving loops.  Prevent the
+	 warning by setting TREE_NO_WARNING.  */
+      if (warn_strict_overflow > 0)
+	{
+	  unsigned int i;
+
+	  for (i = 0; i < n_bbs; ++i)
+	    {
+	      block_stmt_iterator bsi;
+
+	      for (bsi = bsi_start (copied_bbs[i]);
+		   !bsi_end_p (bsi);
+		   bsi_next (&bsi))
+		{
+		  tree stmt = bsi_stmt (bsi);
+		  if (TREE_CODE (stmt) == COND_EXPR)
+		    TREE_NO_WARNING (stmt) = 1;
+		  else if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+		    {
+		      tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+		      if (COMPARISON_CLASS_P (rhs))
+			TREE_NO_WARNING (stmt) = 1;
+		    }
+		}
+	    }
+	}
+
       /* Ensure that the latch and the preheader is simple (we know that they
 	 are not now, since there was the loop exit condition.  */
-      loop_split_edge_with (loop_preheader_edge (loop), NULL);
-      loop_split_edge_with (loop_latch_edge (loop), NULL);
+      split_edge (loop_preheader_edge (loop));
+      split_edge (loop_latch_edge (loop));
     }
 
   free (bbs);
   free (copied_bbs);
 
-  loop_optimizer_finalize (loops, NULL);
+  loop_optimizer_finalize ();
+  return 0;
 }
 
 static bool