cse.c (find_comparison_args): Check that we can reverse a comparison if needed…

cse.c (find_comparison_args): Check that we can reverse a comparison if needed before accepting the substitution.

        * cse.c (find_comparison_args): Check that we can reverse a
        comparison if needed before accepting the substitution.

From-SVN: r37064

gcc/ChangeLog

 2000-10-25  Richard Henderson  <rth@redhat.com>
 
+	* cse.c (find_comparison_args): Check that we can reverse a
+	comparison if needed before accepting the substitution.
+
+2000-10-25  Richard Henderson  <rth@redhat.com>
+
 	* reload.c (find_reloads_address_part): Kill rtx obstack hackery.
 
 2000-10-25  Richard Henderson  <rth@redhat.com>

gcc/cse.c

@@ -3234,6 +3234,12 @@ find_comparison_args (code, parg1, parg2, pmode1, pmode2)
       if (x == 0)
 	break;
 
+      /* If we need to reverse the comparison, make sure that that is
+	 possible -- we can't necessarily infer the value of GE from LT
+	 with floating-point operands.  */
+      if (reverse_code && ! can_reverse_comparison_p (x, NULL_RTX))
+	break;
+
       arg1 = XEXP (x, 0), arg2 = XEXP (x, 1);
       if (GET_RTX_CLASS (GET_CODE (x)) == '<')
 	code = GET_CODE (x);