+2005-07-02 Andrew Pinski <pinskia@physics.uc.edu>
+
+ PR middle-end/14490
+ * fold-const.c (fold_binary): Handle the return value of
+ fold_to_nonsharp_ineq_using_bound if we get back the same operand back.
+ Implement "X +- C1 CMP C2" folding to "X CMP C2 -+ C1".
+
2005-07-02 Jeff Law <law@redhat.com>
* tree-ssa-dom.c (find_equivalent_equality_comparison): Do not
&& !TREE_SIDE_EFFECTS (arg1))
{
tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1);
- if (tem)
+ if (tem && !operand_equal_p (tem, arg0, 0))
return fold_build2 (code, type, tem, arg1);
tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0);
- if (tem)
+ if (tem && !operand_equal_p (tem, arg1, 0))
return fold_build2 (code, type, arg0, tem);
}
}
}
+ /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */
+ if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
+ && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST
+ && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1))
+ && !TYPE_UNSIGNED (TREE_TYPE (arg1))
+ && !(flag_wrapv || flag_trapv))
+ && (TREE_CODE (arg1) == INTEGER_CST
+ && !TREE_OVERFLOW (arg1)))
+ {
+ tree const1 = TREE_OPERAND (arg0, 1);
+ tree const2 = arg1;
+ tree variable = TREE_OPERAND (arg0, 0);
+ tree lhs;
+ int lhs_add;
+ lhs_add = TREE_CODE (arg0) != PLUS_EXPR;
+
+ lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR,
+ TREE_TYPE (arg1), const2, const1);
+ if (TREE_CODE (lhs) == TREE_CODE (arg1)
+ && (TREE_CODE (lhs) != INTEGER_CST
+ || !TREE_OVERFLOW (lhs)))
+ return fold_build2 (code, type, variable, lhs);
+ }
+
if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
{
tree targ0 = strip_float_extensions (arg0);
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* We going into an infinite loop in fold because we
+ were mishandling the return value of
+ fold_to_nonsharp_ineq_using_bound. */
+_Bool f();
+void g(int);
+void h (int old_size)
+{
+ int new_size = old_size, i;
+ g(old_size - 1);
+ i = 0;
+ while (i < old_size - 1)
+ {
+ if (f())
+ {
+ i++;
+ continue;
+ }
+ while (i < old_size - 1)
+ i++;
+ }
+ g(new_size);
+}