+ enum rtx_code invcode = op0code == PLUS ? MINUS : PLUS;
+ rtx tem = simplify_gen_binary (invcode, cmp_mode, op1, c);
+
+ /* Detect an infinite recursive condition, where we oscillate at this
+ simplification case between:
+ A + B == C <---> C - B == A,
+ where A, B, and C are all constants with non-simplifiable expressions,
+ usually SYMBOL_REFs. */
+ if (GET_CODE (tem) == invcode
+ && CONSTANT_P (x)
+ && rtx_equal_p (c, XEXP (tem, 1)))
+ return NULL_RTX;