[PATCH, i386]: Simplify AND-extended address decomposition

[Uros Bizjak]

Hello!

Since we use simplify_gen_subreg on address part, we can use it for
DImode subreg of SImode address as well. simplify_gen_subreg knows how
to strip subreg.

2012-10-29  Uros Bizjak  <ubiz...@gmail.com>

        * config/i386/i386.c (ix86_decompose_address): Use simplify_gen_subreg
        for all addresses, zero-extended with AND.

Tested on x86_64-pc-linux-gnu {,-m32}, committed to mainline SVN.

Uros.

Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c  (revision 192933)
+++ config/i386/i386.c  (working copy)
@@ -11810,23 +11810,11 @@ ix86_decompose_address (rtx addr, struct ix86_addr
       else if (GET_CODE (addr) == AND
               && const_32bit_mask (XEXP (addr, 1), DImode))
        {
-         addr = XEXP (addr, 0);
+         addr = simplify_gen_subreg (SImode, XEXP (addr, 0), DImode, 0);
+         if (addr == NULL_RTX)
+           return 0;
 
-         /* Adjust SUBREGs.  */
-         if (GET_CODE (addr) == SUBREG
-             && GET_MODE (SUBREG_REG (addr)) == SImode)
-           {
-             addr = SUBREG_REG (addr);
-             if (CONST_INT_P (addr))
-               return 0;
-           }
-         else if (GET_MODE (addr) == DImode)
-           {
-             addr = simplify_gen_subreg (SImode, addr, DImode, 0);
-             if (addr == NULL_RTX)
-               return 0;
-           }
-         else if (GET_MODE (addr) != VOIDmode)
+         if (CONST_INT_P (addr))
            return 0;
        }
     }