tree-vrp.c (maybe_add_assert_expr): Don't assert ASSERT_EXPRs for single-use variable.

	* tree-vrp.c (maybe_add_assert_expr): Don't assert
	ASSERT_EXPRs for single-use variable.

From-SVN: r98278

gcc/ChangeLog

@@ -3,6 +3,9 @@
 	* tree-vrp.c (compare_values): Check that VAL1 and VAL2 are
 	both pointers or both integers.
 
+	* tree-vrp.c (maybe_add_assert_expr): Don't assert
+	ASSERT_EXPRs for single-use variable.
+
 2005-04-17  Richard Sandiford  <rsandifo@redhat.com>
 
 	* config/mips/iris6.h (DRIVER_SELF_SPECS): Check -march as well as

gcc/tree-vrp.c

@@ -1446,6 +1446,14 @@ maybe_add_assert_expr (basic_block bb)
 	{
 	  tree cond;
 
+	  /* If OP is used only once, namely in this STMT, don't
+	     bother inserting an ASSERT_EXPR for it.  Such an
+	     ASSERT_EXPR would do nothing but increase compile time.
+	     Experiments show that with this simple check, we can save
+	     more than 20% of ASSERT_EXPRs.  */
+	  if (has_single_use (op))
+	    continue;
+
 	  SET_BIT (found, SSA_NAME_VERSION (op));
 
 	  cond = infer_value_range (stmt, op);