2009-04-15 Rafael Avila de Espindola <espindola@google.com>

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

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 0059443..37865e2 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -1,6 +1,6 @@
 /* Induction variable optimizations.
-   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software
-   Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   Free Software Foundation, Inc.
    
 This file is part of GCC.
    
@@ -219,15 +219,12 @@ struct ivopts_data
   /* The currently optimized loop.  */
   struct loop *current_loop;
 
-  /* Are we optimizing for speed?  */
-  bool speed;
+  /* Numbers of iterations for all exits of the current loop.  */
+  struct pointer_map_t *niters;
 
   /* Number of registers used in it.  */
   unsigned regs_used;
 
-  /* Numbers of iterations for all exits of the current loop.  */
-  struct pointer_map_t *niters;
-
   /* The size of version_info array allocated.  */
   unsigned version_info_size;
 
@@ -237,9 +234,6 @@ struct ivopts_data
   /* The bitmap of indices in version_info whose value was changed.  */
   bitmap relevant;
 
-  /* The maximum invariant id.  */
-  unsigned max_inv_id;
-
   /* The uses of induction variables.  */
   VEC(iv_use_p,heap) *iv_uses;
 
@@ -249,9 +243,15 @@ struct ivopts_data
   /* A bitmap of important candidates.  */
   bitmap important_candidates;
 
+  /* The maximum invariant id.  */
+  unsigned max_inv_id;
+
   /* Whether to consider just related and important candidates when replacing a
      use.  */
   bool consider_all_candidates;
+
+  /* Are we optimizing for speed?  */
+  bool speed;
 };
 
 /* An assignment of iv candidates to uses.  */
@@ -884,7 +884,7 @@ determine_biv_step (gimple phi)
   if (!is_gimple_reg (name))
     return NULL_TREE;
 
-  if (!simple_iv (loop, phi, name, &iv, true))
+  if (!simple_iv (loop, loop, name, &iv, true))
     return NULL_TREE;
 
   return integer_zerop (iv.step) ? NULL_TREE : iv.step;
@@ -990,7 +990,7 @@ find_givs_in_stmt_scev (struct ivopts_data *data, gimple stmt, affine_iv *iv)
   if (TREE_CODE (lhs) != SSA_NAME)
     return false;
 
-  if (!simple_iv (loop, stmt, lhs, iv, true))
+  if (!simple_iv (loop, loop_containing_stmt (stmt), lhs, iv, true))
     return false;
   iv->base = expand_simple_operations (iv->base);
 
@@ -2071,9 +2071,7 @@ add_candidate_1 (struct ivopts_data *data,
     {
       orig_type = TREE_TYPE (base);
       type = generic_type_for (orig_type);
-      /* Don't convert the base to the generic type for pointers as the generic
-        type is an integer type with the same size as the pointer type.  */
-      if (type != orig_type && !POINTER_TYPE_P (orig_type))
+      if (type != orig_type)
        {
          base = fold_convert (type, base);
          step = fold_convert (type, step);
@@ -3844,7 +3842,12 @@ may_eliminate_iv (struct ivopts_data *data,
     return false;
 
   cand_value_at (loop, cand, use->stmt, nit, &bnd);
+
   *bound = aff_combination_to_tree (&bnd);
+  /* It is unlikely that computing the number of iterations using division
+     would be more profitable than keeping the original induction variable.  */
+  if (expression_expensive_p (*bound))
+    return false;
   return true;
 }
 
@@ -4355,6 +4358,8 @@ iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs,
 static comp_cost
 iv_ca_cost (struct iv_ca *ivs)
 {
+  /* This was a conditional expression but it triggered a bug in
+     Sun C 5.5.  */
   if (ivs->bad_uses)
     return infinite_cost;
   else
@@ -5217,63 +5222,6 @@ unshare_and_remove_ssa_names (tree ref)
   return ref;
 }
 
-/* Extract the alias analysis info for the memory reference REF.  There are
-   several ways how this information may be stored and what precisely is
-   its semantics depending on the type of the reference, but there always is
-   somewhere hidden one _DECL node that is used to determine the set of
-   virtual operands for the reference.  The code below deciphers this jungle
-   and extracts this single useful piece of information.  */
-
-static tree
-get_ref_tag (tree ref, tree orig)
-{
-  tree var = get_base_address (ref);
-  tree aref = NULL_TREE, tag, sv;
-  HOST_WIDE_INT offset, size, maxsize;
-
-  for (sv = orig; handled_component_p (sv); sv = TREE_OPERAND (sv, 0))
-    {
-      aref = get_ref_base_and_extent (sv, &offset, &size, &maxsize);
-      if (ref)
-       break;
-    }
-
-  if (!var)
-    return NULL_TREE;
-
-  if (TREE_CODE (var) == INDIRECT_REF)
-    {
-      /* If the base is a dereference of a pointer, first check its name memory
-        tag.  If it does not have one, use its symbol memory tag.  */
-      var = TREE_OPERAND (var, 0);
-      if (TREE_CODE (var) != SSA_NAME)
-       return NULL_TREE;
-
-      if (SSA_NAME_PTR_INFO (var))
-       {
-         tag = SSA_NAME_PTR_INFO (var)->name_mem_tag;
-         if (tag)
-           return tag;
-       }
- 
-      var = SSA_NAME_VAR (var);
-      tag = symbol_mem_tag (var);
-      gcc_assert (tag != NULL_TREE);
-      return tag;
-    }
-  else
-    { 
-      if (!DECL_P (var))
-       return NULL_TREE;
-
-      tag = symbol_mem_tag (var);
-      if (tag)
-       return tag;
-
-      return var;
-    }
-}
-
 /* Copies the reference information from OLD_REF to NEW_REF.  */
 
 static void
@@ -5282,10 +5230,7 @@ copy_ref_info (tree new_ref, tree old_ref)
   if (TREE_CODE (old_ref) == TARGET_MEM_REF)
     copy_mem_ref_info (new_ref, old_ref);
   else
-    {
-      TMR_ORIGINAL (new_ref) = unshare_and_remove_ssa_names (old_ref);
-      TMR_TAG (new_ref) = get_ref_tag (old_ref, TMR_ORIGINAL (new_ref));
-    }
+    TMR_ORIGINAL (new_ref) = unshare_and_remove_ssa_names (old_ref);
 }
 
 /* Rewrites USE (address that is an iv) using candidate CAND.  */