2005-04-27 Paolo Bonzini <bonzini@gnu.org>

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-loop-ivcanon.c

diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
index 7271878..f2898b5 100644 (file)
--- a/gcc/tree-ssa-loop-ivcanon.c
+++ b/gcc/tree-ssa-loop-ivcanon.c
@@ -1,5 +1,5 @@
 /* Induction variable canonicalization.
-   Copyright (C) 2004 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005 Free Software Foundation, Inc.
    
 This file is part of GCC.
    
@@ -74,9 +74,9 @@ create_canonical_iv (struct loop *loop, edge exit, tree niter)
     }
 
   cond = last_stmt (exit->src);
-  in = exit->src->succ;
+  in = EDGE_SUCC (exit->src, 0);
   if (in == exit)
-    in = in->succ_next;
+    in = EDGE_SUCC (exit->src, 1);
 
   /* Note that we do not need to worry about overflows, since
      type of niter is always unsigned and all comparisons are
@@ -97,7 +97,7 @@ create_canonical_iv (struct loop *loop, edge exit, tree niter)
   COND_EXPR_COND (cond) = build2 (cmp, boolean_type_node,
                                  var,
                                  build_int_cst (type, 0));
-  modify_stmt (cond);
+  update_stmt (cond);
 }
 
 /* Computes an estimated number of insns in LOOP.  */
@@ -168,27 +168,24 @@ try_unroll_loop_completely (struct loops *loops ATTRIBUTE_UNUSED,
     
   if (n_unroll)
     {
-      if (!flag_unroll_loops)
-       return false;
-
       old_cond = COND_EXPR_COND (cond);
       COND_EXPR_COND (cond) = dont_exit;
-      modify_stmt (cond);
+      update_stmt (cond);
 
-#if 0
-      /* The necessary infrastructure is not in yet.  */
       if (!tree_duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop),
                                               loops, n_unroll, NULL,
                                               NULL, NULL, NULL, 0))
-#endif
        {
          COND_EXPR_COND (cond) = old_cond;
+         update_stmt (cond);
          return false;
        }
     }
   
   COND_EXPR_COND (cond) = do_exit;
-  modify_stmt (cond);
+  update_stmt (cond);
+
+  update_ssa (TODO_update_ssa);
 
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "Unrolled loop %d completely.\n", loop->num);
@@ -223,12 +220,23 @@ canonicalize_loop_induction_variables (struct loops *loops, struct loop *loop,
       niter = fold (build2 (MINUS_EXPR, TREE_TYPE (niter), niter,
                            build_int_cst (TREE_TYPE (niter), 1)));
     }
-  else if (try_eval)
-    niter = find_loop_niter_by_eval (loop, &exit);
-
-  if (chrec_contains_undetermined (niter)
-      || TREE_CODE (niter) != INTEGER_CST)
-    return false;
+  else
+    {
+      /* If the loop has more than one exit, try checking all of them
+        for # of iterations determinable through scev.  */
+      if (!loop->single_exit)
+       niter = find_loop_niter (loop, &exit);
+
+      /* Finally if everything else fails, try brute force evaluation.  */
+      if (try_eval
+         && (chrec_contains_undetermined (niter)
+             || TREE_CODE (niter) != INTEGER_CST))
+       niter = find_loop_niter_by_eval (loop, &exit);
+
+      if (chrec_contains_undetermined (niter)
+         || TREE_CODE (niter) != INTEGER_CST)
+       return false;
+    }
 
   if (dump_file && (dump_flags & TDF_DETAILS))
     {
@@ -254,20 +262,23 @@ canonicalize_induction_variables (struct loops *loops)
 {
   unsigned i;
   struct loop *loop;
+  bool changed = false;
   
   for (i = 1; i < loops->num; i++)
     {
       loop = loops->parray[i];
 
       if (loop)
-       canonicalize_loop_induction_variables (loops, loop, true, false, true);
+       changed |= canonicalize_loop_induction_variables (loops, loop,
+                                                         true, false, true);
     }
 
-#if 0
-  /* The necessary infrastructure is not in yet.  */
+  /* Clean up the information about numbers of iterations, since brute force
+     evaluation could reveal new information.  */
+  scev_reset ();
+
   if (changed)
     cleanup_tree_cfg_loop ();
-#endif
 }
 
 /* Unroll LOOPS completely if they iterate just few times.  */
@@ -288,12 +299,13 @@ tree_unroll_loops_completely (struct loops *loops)
 
       changed |= canonicalize_loop_induction_variables (loops, loop,
                                                        false, true,
-                                                       !flag_ivcanon);
+                                                       !flag_tree_loop_ivcanon);
     }
 
-#if 0
-  /* The necessary infrastructure is not in yet.  */
+  /* Clean up the information about numbers of iterations, since complete
+     unrolling might have invalidated it.  */
+  scev_reset ();
+
   if (changed)
     cleanup_tree_cfg_loop ();
-#endif
 }