re PR target/37878 (PPC64 ldu command generated with invalid offset)

        PR target/37878
        * config/rs6000/predicates.md (word_offset_memref_operand):
        Restructure code and look inside auto-inc/dec addresses.

From-SVN: r141450

gcc/ChangeLog

+2008-10-29  David Edelsohn  <edelsohn@gnu.org>
+
+	PR target/37878
+	* config/rs6000/predicates.md (word_offset_memref_operand):
+	Restructure code and look inside auto-inc/dec addresses.
+	
 2008-10-29  Steve Ellcey  <sje@cup.hp.com>
 
 	PR target/32277

gcc/config/rs6000/predicates.md

@@ -373,11 +373,23 @@
 
 ;; Return 1 if the operand is a memory operand with an address divisible by 4
 (define_predicate "word_offset_memref_operand"
-  (and (match_operand 0 "memory_operand")
-       (match_test "GET_CODE (XEXP (op, 0)) != PLUS
-		    || ! REG_P (XEXP (XEXP (op, 0), 0)) 
-		    || GET_CODE (XEXP (XEXP (op, 0), 1)) != CONST_INT
-		    || INTVAL (XEXP (XEXP (op, 0), 1)) % 4 == 0")))
+  (match_operand 0 "memory_operand")
+{
+  /* Address inside MEM.  */
+  op = XEXP (op, 0);
+
+  /* Extract address from auto-inc/dec.  */
+  if (GET_CODE (op) == PRE_INC
+      || GET_CODE (op) == PRE_DEC)
+    op = XEXP (op, 0);
+  else if (GET_CODE (op) == PRE_MODIFY)
+    op = XEXP (op, 1);
+
+  return (GET_CODE (op) != PLUS
+	  || ! REG_P (XEXP (op, 0))
+	  || GET_CODE (XEXP (op, 1)) != CONST_INT
+	  || INTVAL (XEXP (op, 1)) % 4 == 0);
+})
 
 ;; Return 1 if the operand is an indexed or indirect memory operand.
 (define_predicate "indexed_or_indirect_operand"