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Re: [PATCH][4/n] referenced-vars TLC
On Wed, May 23, 2012 at 7:25 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> 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.
I opened:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53466
--
H.J.