(rtx_equal_for_tmemref_p): Commutative operations are identical if the

operands match in the opposite order.

From-SVN: r6732

gcc/sched.c

 /* Instruction scheduling pass.
-   Copyright (C) 1992, 1993 Free Software Foundation, Inc.
+   Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
    Contributed by Michael Tiemann (tiemann@cygnus.com)
    Enhanced by, and currently maintained by, Jim Wilson (wilson@cygnus.com)
 
@@ -481,6 +481,19 @@ rtx_equal_for_memref_p (x, y)
   if (code == SYMBOL_REF)
     return XSTR (x, 0) == XSTR (y, 0);
 
+  /* For commutative operations, the RTX match if the operand match in any
+     order.  Also handle the simple binary and unary cases without a loop.  */
+  if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c')
+    return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0))
+	     && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1)))
+	    || (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1))
+		&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0))));
+  else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2')
+    return (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0))
+	    && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1)));
+  else if (GET_RTX_CLASS (code) == '1')
+    return rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0));
+
   /* Compare the elements.  If any pair of corresponding elements
      fail to match, return 0 for the whole things.  */