[Bug rtl-optimization/50762] ICE: in extract_insn, at recog.c:2137 (unrecognizable insn)

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50762

Uros Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ubizjak at gmail dot com

--- Comment #9 from Uros Bizjak <ubizjak at gmail dot com> 2011-11-09 20:48:31 UTC ---
(In reply to comment #8)

> The zero_extend is a fixed part of the insn pattern in question:
> 
> (define_insn "*lea_4_zext"
>   [(set (match_operand:DI 0 "register_operand" "=r")
>         (zero_extend:DI
>           (match_operand:SI 1 "lea_address_operand" "p")))]
> 
> Reload only ever changes what is *inside* the operands.  It does not change the
> fixed parts of the pattern (outside of operands).

If this is the case, then (const_int 1) is perfectly acceptable here. It is
accepted as a valid address operand (most of the magic happens in
x86_decompose_address, followed by ix86_legitimate_address_p), and would result
in somehing like

    leal    1(,1), %eax


0000000000000000 <.text>:
   0:    8d 04 25 01 00 00 00     lea    0x1,%eax

Not quite effective way to load immediate 1, but whatnot.

> Not sure why that doesn't happen.  I'll have a look.

Thanks!