[PATCH, i386]: Reject wrong RTXes from index early

[Uros Bizjak]

Hello!

Just a small optimization, we can reject non-register RTXes and wrong
subregs from index early.  No functional change - these RTXes were
rejected in ix86_legitimate_address_p anyway.

2011-07-21  Uros Bizjak  <ubiz...@gmail.com>

        * config/i386/i386.c (ix86_decompose_address): Reject all but
        register operands and DImode hard registers in index.

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

Uros.

Index: i386.c
===================================================================
--- i386.c      (revision 176550)
+++ i386.c      (working copy)
@@ -11203,7 +11203,9 @@
        ;
       /* Allow only subregs of DImode hard regs.  */
       else if (GET_CODE (index) == SUBREG
-              && !register_no_elim_operand (SUBREG_REG (index), DImode))
+              && register_no_elim_operand (SUBREG_REG (index), DImode))
+       ;
+      else
        return 0;
     }