[Bug target/47744] [x32] ICE: in reload_cse_simplify_operands, at postreload.c:403

["hjl.tools at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47744

--- Comment #17 from H.J. Lu <hjl.tools at gmail dot com> 2011-07-17 21:21:01 UTC ---
(In reply to comment #16)
> Following patch to original ix86_decompose_address solves all failures for me:
> 
> --cut here--
> Index: i386.c
> ===================================================================
> --- i386.c    (revision 176373)
> +++ i386.c    (working copy)
> @@ -11149,8 +11149,11 @@ ix86_decompose_address (rtx addr, struct
>          return 0;
>            break;
> 
> -        case REG:
>          case SUBREG:
> +          if (GET_CODE (op) != REG)
> +        return 0;
> +
> +        case REG:
>            if (!base)
>          base = op;
>            else if (!index)
> --cut here--
> 
> The patch simply prevents subregs of anything else than registers in addresses.
> 
> So, instead of mess as in comment 14, we have a sequence of two instructions:
> 
> (insn 185 87 89 3 (set (reg:DI 0 ax)
>         (plus:DI (reg/f:DI 7 sp)
>             (const_int 200 [0xc8]))) pr47744.c:5 248 {*lea_1}
>      (nil))
> 
> (insn 89 185 90 3 (set (reg:SI 40 r11 [177])
>         (plus:SI (plus:SI (mult:SI (reg:SI 40 r11 [175])
>                     (const_int 8 [0x8]))
>                 (reg:SI 0 ax))
>             (const_int -160 [0xffffffffffffff60]))) pr47744.c:5 286
> {*lea_general_3}
>      (nil))
> 
> Please note, that "normal" lea instructions are now generated, no need for some
> special x32 versions.
> 
> BTW: I'd also argue that this sequence is more correct w.r.t. to overflows, but
> I didn't investigate this since it is already late in the night here...

I will give it a try on x32 branch.  Thanks.