tree-ssa-dom.c (record_equivalences_from_incoming_edge): Rework slightly to…

tree-ssa-dom.c (record_equivalences_from_incoming_edge): Rework slightly to avoid creating and folding useless trees.

        * tree-ssa-dom.c (record_equivalences_from_incoming_edge): Rework
	slightly to avoid creating and folding useless trees.  Simplify
        slightly by restricting to INTEGER_CSTs and using int_fits_type_p.

From-SVN: r197060

gcc/ChangeLog

+2013-03-25  Jeff Law  <law@redhat.com>
+
+	* tree-ssa-dom.c (record_equivalences_from_incoming_edge): Rework
+	slightly to avoid creating and folding useless trees.  Simplify
+	slightly by restricting to INTEGER_CSTs and using int_fits_type_p.
+
 2013-03-25  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.md (*zero_extendsidi2): Merge with

gcc/tree-ssa-dom.c

@@ -1135,12 +1135,13 @@ record_equivalences_from_incoming_edge (basic_block bb)
 	  if (lhs)
 	    record_equality (lhs, rhs);
 
-	  /* If LHS is an SSA_NAME and RHS is a constant and LHS was set
-	     via a widening type conversion, then we may be able to record
+	  /* If LHS is an SSA_NAME and RHS is a constant integer and LHS was
+	     set via a widening type conversion, then we may be able to record
 	     additional equivalences.  */
 	  if (lhs
 	      && TREE_CODE (lhs) == SSA_NAME
-	      && is_gimple_constant (rhs))
+	      && is_gimple_constant (rhs)
+	      && TREE_CODE (rhs) == INTEGER_CST)
 	    {
 	      gimple defstmt = SSA_NAME_DEF_STMT (lhs);
 
@@ -1149,16 +1150,14 @@ record_equivalences_from_incoming_edge (basic_block bb)
 		  && CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (defstmt)))
 		{
 		  tree old_rhs = gimple_assign_rhs1 (defstmt);
-		  tree newval = fold_convert (TREE_TYPE (old_rhs), rhs);
-
-		  /* If this was a widening conversion and if RHS is converted
-		     to the type of OLD_RHS and has the same value, then we
-		     can record an equivalence between OLD_RHS and the
-		     converted representation of RHS.  */
-		  if ((TYPE_PRECISION (TREE_TYPE (lhs))
-		       > TYPE_PRECISION (TREE_TYPE (old_rhs)))
-		      && operand_equal_p (rhs, newval, 0))
-		    record_equality (old_rhs, newval);
+
+		  /* If the constant is in the range of the type of OLD_RHS,
+		     then convert the constant and record the equivalence.  */
+		  if (int_fits_type_p (rhs, TREE_TYPE (old_rhs)))
+		    {
+		      tree newval = fold_convert (TREE_TYPE (old_rhs), rhs);
+		      record_equality (old_rhs, newval);
+		    }
 		}
 	    }