Index: config/i386/predicates.md
===================================================================
--- config/i386/predicates.md	(revision 177456)
+++ config/i386/predicates.md	(working copy)
@@ -801,6 +801,10 @@
   struct ix86_address parts;
   int ok;
 
+  /*  LEA handles zero-extend by itself.  */
+  if (GET_CODE (op) == ZERO_EXTEND)
+    return false;
+
   ok = ix86_decompose_address (op, &parts);
   gcc_assert (ok);
   return parts.seg == SEG_DEFAULT;
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c	(revision 177456)
+++ config/i386/i386.c	(working copy)
@@ -11146,6 +11146,14 @@ ix86_decompose_address (rtx addr, struct ix86_addr
   int retval = 1;
   enum ix86_address_seg seg = SEG_DEFAULT;
 
+  /* Allow zero-extended SImode addresses,
+     they will be emitted with addr32 prefix.  */
+  if (TARGET_64BIT
+      && GET_CODE (addr) == ZERO_EXTEND
+      && GET_MODE (addr) == DImode
+      && GET_MODE (XEXP (addr, 0)) == SImode)
+    addr = XEXP (addr, 0);
+ 
   if (REG_P (addr))
     base = addr;
   else if (GET_CODE (addr) == SUBREG)
@@ -14163,9 +14171,13 @@ ix86_print_operand_address (FILE *file, rtx addr)
     }
   else
     {
-      /* Print DImode registers on 64bit targets to avoid addr32 prefixes.  */
-      int code = TARGET_64BIT ? 'q' : 0;
+      int code = 0;
 
+      /* Print SImode registers for zero-extended addresses to force
+	 addr32 prefix.  Otherwise print DImode registers to avoid it.  */
+      if (TARGET_64BIT)
+	code = (GET_CODE (addr) == ZERO_EXTEND) ? 'l' : 'q';
+
       if (ASSEMBLER_DIALECT == ASM_ATT)
 	{
 	  if (disp)
@@ -21776,7 +21788,8 @@ assign_386_stack_local (enum machine_mode mode, en
 }
 
 /* Calculate the length of the memory address in the instruction
-   encoding.  Does not include the one-byte modrm, opcode, or prefix.  */
+   encoding.  Includes addr32 prefix, does not include the one-byte modrm,
+   opcode, or other prefixes.  */
 
 int
 memory_address_length (rtx addr)
@@ -21803,8 +21816,10 @@ memory_address_length (rtx addr)
   base = parts.base;
   index = parts.index;
   disp = parts.disp;
-  len = 0;
 
+  /* Add length of addr32 prefix.  */
+  len = (GET_CODE (addr) == ZERO_EXTEND);
+
   /* Rule of thumb:
        - esp as the base always wants an index,
        - ebp as the base always wants a displacement,