* tree-ssa-dom.c (simplify_switch_and_lookup_avail_expr): Code

	to simplify SWITCH_EXPR_CODE moved from here to ...
	* tree-ssa-forwprop.c (simplify_switch_expr): Here.
	(tree-ssa-forward_propagate_single_use_vars): Call
	simplify_switch_expr when appropriate.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@108738 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 68 insertions, 65 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 03f63c34d1f..d30feed3cfd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2005-12-18  Jeff Law  <law@redhat.com>
+
+	* tree-ssa-dom.c (simplify_switch_and_lookup_avail_expr): Code
+	to simplify SWITCH_EXPR_CODE moved from here to ...
+	* tree-ssa-forwprop.c (simplify_switch_expr): Here.
+	(tree-ssa-forward_propagate_single_use_vars): Call
+	simplify_switch_expr when appropriate.
+
 2005-12-17  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	* doc/objc.texi (Type encoding): Add documentation about encoding
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index 8e4a1995471..00659f3a670 100644
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -274,7 +274,6 @@ static void record_cond (tree, tree);
 static void record_const_or_copy (tree, tree);
 static void record_equality (tree, tree);
 static tree simplify_cond_and_lookup_avail_expr (tree, stmt_ann_t, int);
-static tree simplify_switch_and_lookup_avail_expr (tree, int);
 static tree find_equivalent_equality_comparison (tree);
 static void record_range (tree, basic_block);
 static bool extract_range_from_cond (tree, tree *, tree *, int *);
@@ -2120,67 +2119,6 @@ simplify_cond_and_lookup_avail_expr (tree stmt,
   return 0;
 }
 
-/* STMT is a SWITCH_EXPR for which we could not trivially determine its
-   result.  This routine attempts to find equivalent forms of the
-   condition which we may be able to optimize better.  */
-
-static tree
-simplify_switch_and_lookup_avail_expr (tree stmt, int insert)
-{
-  tree cond = SWITCH_COND (stmt);
-  tree def, to, ti;
-
-  /* The optimization that we really care about is removing unnecessary
-     casts.  That will let us do much better in propagating the inferred
-     constant at the switch target.  */
-  if (TREE_CODE (cond) == SSA_NAME)
-    {
-      def = SSA_NAME_DEF_STMT (cond);
-      if (TREE_CODE (def) == MODIFY_EXPR)
-	{
-	  def = TREE_OPERAND (def, 1);
-	  if (TREE_CODE (def) == NOP_EXPR)
-	    {
-	      int need_precision;
-	      bool fail;
-
-	      def = TREE_OPERAND (def, 0);
-
-#ifdef ENABLE_CHECKING
-	      /* ??? Why was Jeff testing this?  We are gimple...  */
-	      gcc_assert (is_gimple_val (def));
-#endif
-
-	      to = TREE_TYPE (cond);
-	      ti = TREE_TYPE (def);
-
-	      /* If we have an extension that preserves value, then we
-		 can copy the source value into the switch.  */
-
-	      need_precision = TYPE_PRECISION (ti);
-	      fail = false;
-	      if (TYPE_UNSIGNED (to) && !TYPE_UNSIGNED (ti))
-		fail = true;
-	      else if (!TYPE_UNSIGNED (to) && TYPE_UNSIGNED (ti))
-		need_precision += 1;
-	      if (TYPE_PRECISION (to) < need_precision)
-		fail = true;
-
-	      if (!fail)
-		{
-		  SWITCH_COND (stmt) = def;
-		  mark_stmt_modified (stmt);
-
-		  return lookup_avail_expr (stmt, insert);
-		}
-	    }
-	}
-    }
-
-  return 0;
-}
-
-
 /* CONST_AND_COPIES is a table which maps an SSA_NAME to the current
    known value for that SSA_NAME (or NULL if no value is known).  
 
@@ -2473,9 +2411,6 @@ eliminate_redundant_computations (tree stmt, stmt_ann_t ann)
      the hash table, simplify the condition and try again.  */
   if (! cached_lhs && TREE_CODE (stmt) == COND_EXPR)
     cached_lhs = simplify_cond_and_lookup_avail_expr (stmt, ann, insert);
-  /* Similarly for a SWITCH_EXPR.  */
-  else if (!cached_lhs && TREE_CODE (stmt) == SWITCH_EXPR)
-    cached_lhs = simplify_switch_and_lookup_avail_expr (stmt, insert);
 
   opt_stats.num_exprs_considered++;
 
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index e3978d8c2a2..2d89494ca73 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -739,6 +739,61 @@ simplify_not_neg_expr (tree stmt)
     }
 }
 
+/* STMT is a SWITCH_EXPR for which we attempt to find equivalent forms of
+   the condition which we may be able to optimize better.  */
+
+static void
+simplify_switch_expr (tree stmt)
+{
+  tree cond = SWITCH_COND (stmt);
+  tree def, to, ti;
+
+  /* The optimization that we really care about is removing unnecessary
+     casts.  That will let us do much better in propagating the inferred
+     constant at the switch target.  */
+  if (TREE_CODE (cond) == SSA_NAME)
+    {
+      def = SSA_NAME_DEF_STMT (cond);
+      if (TREE_CODE (def) == MODIFY_EXPR)
+	{
+	  def = TREE_OPERAND (def, 1);
+	  if (TREE_CODE (def) == NOP_EXPR)
+	    {
+	      int need_precision;
+	      bool fail;
+
+	      def = TREE_OPERAND (def, 0);
+
+#ifdef ENABLE_CHECKING
+	      /* ??? Why was Jeff testing this?  We are gimple...  */
+	      gcc_assert (is_gimple_val (def));
+#endif
+
+	      to = TREE_TYPE (cond);
+	      ti = TREE_TYPE (def);
+
+	      /* If we have an extension that preserves value, then we
+		 can copy the source value into the switch.  */
+
+	      need_precision = TYPE_PRECISION (ti);
+	      fail = false;
+	      if (TYPE_UNSIGNED (to) && !TYPE_UNSIGNED (ti))
+		fail = true;
+	      else if (!TYPE_UNSIGNED (to) && TYPE_UNSIGNED (ti))
+		need_precision += 1;
+	      if (TYPE_PRECISION (to) < need_precision)
+		fail = true;
+
+	      if (!fail)
+		{
+		  SWITCH_COND (stmt) = def;
+		  update_stmt (stmt);
+		}
+	    }
+	}
+    }
+}
+
 /* Main entry point for the forward propagation optimizer.  */
 
 static void
@@ -788,6 +843,11 @@ tree_ssa_forward_propagate_single_use_vars (void)
 	      else
 		bsi_next (&bsi);
 	    }
+	  else if (TREE_CODE (stmt) == SWITCH_EXPR)
+	    {
+	      simplify_switch_expr (stmt);
+	      bsi_next (&bsi);
+	    }
 	  else if (TREE_CODE (stmt) == COND_EXPR)
 	    {
 	      forward_propagate_into_cond (stmt);