PR fortran/20897

[pf3gnuchains/gcc-fork.git] / gcc / tree-cfgcleanup.c

diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index d13a536..8cf66cb 100644 (file)
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -1,5 +1,6 @@
 /* CFG cleanup for trees.
-   Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
+   Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -28,7 +29,7 @@ Boston, MA 02110-1301, USA.  */
 #include "hard-reg-set.h"
 #include "basic-block.h"
 #include "output.h"
-#include "errors.h"
+#include "toplev.h"
 #include "flags.h"
 #include "function.h"
 #include "expr.h"
@@ -78,6 +79,9 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
     {
       edge e;
       edge_iterator ei;
+      bool warned;
+
+      fold_defer_overflow_warnings ();
 
       switch (TREE_CODE (expr))
        {
@@ -88,7 +92,10 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
        case SWITCH_EXPR:
          val = fold (SWITCH_COND (expr));
          if (TREE_CODE (val) != INTEGER_CST)
-           return false;
+           {
+             fold_undefer_and_ignore_overflow_warnings ();
+             return false;
+           }
          break;
 
        default:
@@ -97,13 +104,24 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
 
       taken_edge = find_taken_edge (bb, val);
       if (!taken_edge)
-       return false;
+       {
+         fold_undefer_and_ignore_overflow_warnings ();
+         return false;
+       }
 
       /* Remove all the edges except the one that is always executed.  */
+      warned = false;
       for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
        {
          if (e != taken_edge)
            {
+             if (!warned)
+               {
+                 fold_undefer_overflow_warnings
+                   (true, expr, WARN_STRICT_OVERFLOW_CONDITIONAL);
+                 warned = true;
+               }
+
              taken_edge->probability += e->probability;
              taken_edge->count += e->count;
              remove_edge (e);
@@ -112,6 +130,8 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
          else
            ei_next (&ei);
        }
+      if (!warned)
+       fold_undefer_and_ignore_overflow_warnings ();
       if (taken_edge->probability > REG_BR_PROB_BASE)
        taken_edge->probability = REG_BR_PROB_BASE;
     }
@@ -127,14 +147,6 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
   return retval;
 }
 
-/* A list of all the noreturn calls passed to modify_stmt.
-   cleanup_control_flow uses it to detect cases where a mid-block
-   indirect call has been turned into a noreturn call.  When this
-   happens, all the instructions after the call are no longer
-   reachable and must be deleted as dead.  */
-
-VEC(tree,gc) *modified_noreturn_calls;
-
 /* Try to remove superfluous control structures.  */
 
 static bool
@@ -146,13 +158,14 @@ cleanup_control_flow (void)
   tree stmt;
 
   /* Detect cases where a mid-block call is now known not to return.  */
-  while (VEC_length (tree, modified_noreturn_calls))
-    {
-      stmt = VEC_pop (tree, modified_noreturn_calls);
-      bb = bb_for_stmt (stmt);
-      if (bb != NULL && last_stmt (bb) != stmt && noreturn_call_p (stmt))
-       split_block (bb, stmt);
-    }
+  if (cfun->gimple_df)
+    while (VEC_length (tree, MODIFIED_NORETURN_CALLS (cfun)))
+      {
+       stmt = VEC_pop (tree, MODIFIED_NORETURN_CALLS (cfun));
+       bb = bb_for_stmt (stmt);
+       if (bb != NULL && last_stmt (bb) != stmt && noreturn_call_p (stmt))
+         split_block (bb, stmt);
+      }
 
   FOR_EACH_BB (bb)
     {
@@ -581,7 +594,7 @@ cleanup_tree_cfg (void)
 
 /* Cleanup cfg and repair loop structures.  */
 
-void
+bool
 cleanup_tree_cfg_loop (void)
 {
   bool changed = cleanup_tree_cfg ();
@@ -589,8 +602,8 @@ cleanup_tree_cfg_loop (void)
   if (changed)
     {
       bitmap changed_bbs = BITMAP_ALLOC (NULL);
-      fix_loop_structure (changed_bbs);
       calculate_dominance_info (CDI_DOMINATORS);
+      fix_loop_structure (changed_bbs);
 
       /* This usually does nothing.  But sometimes parts of cfg that originally
         were inside a loop get out of it due to edge removal (since they
@@ -604,6 +617,7 @@ cleanup_tree_cfg_loop (void)
 #endif
       scev_reset ();
     }
+  return changed;
 }
 
 /* Merge the PHI nodes at BB into those at BB's sole successor.  */