revert: re PR middle-end/49721 (convert_memory_address_addr_space may generate invalid new insns)

2014-10-14  Andrew Pinski  <apinski@cavium.com>

	Revert:
	2011-08-19  H.J. Lu  <hongjiu.lu@intel.com>

        PR middle-end/49721
        * explow.c (convert_memory_address_addr_space): Also permute the
        conversion and addition of constant for zero-extend.

From-SVN: r216229

gcc/ChangeLog

+2014-10-14  Andrew Pinski  <apinski@cavium.com>
+
+	Revert:
+	2011-08-19  H.J. Lu  <hongjiu.lu@intel.com>
+
+        PR middle-end/49721
+        * explow.c (convert_memory_address_addr_space): Also permute the
+        conversion and addition of constant for zero-extend.
+
 2014-10-14  DJ Delorie  <dj@redhat.com>
 
 	* config/msp430/msp430-modes.def (PSI): Add.

gcc/explow.c

@@ -376,23 +376,18 @@ convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
 
     case PLUS:
     case MULT:
-      /* FIXME: For addition, we used to permute the conversion and
-	 addition operation only if one operand is a constant and
-	 converting the constant does not change it or if one operand
-	 is a constant and we are using a ptr_extend instruction
-	 (POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
-	 may overflow/underflow.  We relax the condition to include
-	 zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
-	 parts of the compiler depend on it.  See PR 49721.
-
+      /* For addition we can safely permute the conversion and addition
+	 operation if one operand is a constant and converting the constant
+	 does not change it or if one operand is a constant and we are
+	 using a ptr_extend instruction  (POINTERS_EXTEND_UNSIGNED < 0).
 	 We can always safely permute them if we are making the address
 	 narrower.  */
       if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
 	  || (GET_CODE (x) == PLUS
 	      && CONST_INT_P (XEXP (x, 1))
-	      && (POINTERS_EXTEND_UNSIGNED != 0
-		  || XEXP (x, 1) == convert_memory_address_addr_space
-		  			(to_mode, XEXP (x, 1), as))))
+	      && (XEXP (x, 1) == convert_memory_address_addr_space
+				   (to_mode, XEXP (x, 1), as)
+                 || POINTERS_EXTEND_UNSIGNED < 0)))
 	return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
 			       convert_memory_address_addr_space
 				 (to_mode, XEXP (x, 0), as),