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Re: [PATCH][4/n] referenced-vars TLC
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Richard Guenther <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 23 May 2012 07:25:03 -0700
- Subject: Re: [PATCH][4/n] referenced-vars TLC
- References: <Pine.LNX.4.64.1205231355550.5860@jbgna.fhfr.qr>
On Wed, May 23, 2012 at 5:00 AM, Richard Guenther <rguenther@suse.de> wrote:
>
> This finally switches us to not record global vars in referenced-vars.
> For this to work I had to re-engineer how we handle global var removal
> from local-decls in remove_unused_locals. ?Incidentially that code
> already had some sort of a bitmap (for some weird reason even), thus
> I borrowed that and simplified the handling. ?You may notice that
> it would be easy to handle all vars that way ...
>
> So eventually 5/n will make referenced-vars go away completely
> (the only serious user seems to be the SSA renamer for its
> SYMS_TO_RENAME bitmap).
>
> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
>
> Richard.
>
> 2012-05-23 ?Richard Guenther ?<rguenther@suse.de>
>
> ? ? ? ?* tree-dfa.c (add_referenced_var_1): Do not add global vars.
> ? ? ? ?* tree-ssa-live.c (mark_all_vars_used_1): Handle global vars
> ? ? ? ?via the global_unused_vars bitmap.
> ? ? ? ?(remove_unused_locals): Handle global vars in local-decls via
> ? ? ? ?a global_unused_vars bitmap instead of the used flag in the
> ? ? ? ?var annotation. ?Simplify global variable handling and removal.
>
This breaks bootstrap on Linux/x86-64:
http://gcc.gnu.org/ml/gcc-regression/2012-05/msg00468.html
Comparing stages 2 and 3
warning: gcc/cc1plus-checksum.o differs
warning: gcc/cc1obj-checksum.o differs
warning: gcc/cc1-checksum.o differs
Bootstrap comparison failure!
gcc/trans-mem.o differs
gcc/gimple-low.o differs
gcc/sese.o differs
make[5]: *** [compare] Error 1
Please make sure that your compiler used for bootstrap
doesn't add anything to .comment section, which will
disable debug compare.
Thanks.
--
H.J.