[Bug middle-end/58970] [4.7/4.8/4.9 Regression] internal compiler error: in get_bit_range, at expr.c:4562

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58970

--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Bernd Edlinger from comment #18)
> Well, how about this version?
> Does'nt it look like a much smaller change?
> 
> --- expr.c.jj	2013-10-31 14:57:05.000000000 +0100
> +++ expr.c	2013-11-04 12:51:55.013931114 +0100
> @@ -4582,7 +4582,8 @@ get_bit_range (unsigned HOST_WIDE_INT *b
>        HOST_WIDE_INT adjust = bitoffset - *bitpos;
>  
>        gcc_assert ((adjust % BITS_PER_UNIT) == 0);
> -      gcc_assert (*offset != NULL_TREE);
> +      if (*offset == NULL_TREE)
> +	*offset = size_zero_node;
>  
>        *bitpos += adjust;
>        *offset

But you then have undefined behavior if *bitpos is HOST_WIDE_INT_MIN.  Or could
for very small other *bitpos and not really small bitoffset, etc.  And, while
you save a few characters on the line, it means it is more expensive at
runtime.
>From gcc-bugs-return-433436-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Nov 04 14:07:54 2013
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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug other/58944] [4.9 Regression] bogus -Wunused-macros warnings when compiling Libreoffice
Date: Mon, 04 Nov 2013 14:07:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idX944

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
   Target Milestone|---                         |4.9.0

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Looks like a system_header check doesn't work anymore.