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Re: fix -fcompare-debug regression in free_lang_data
- From: Alexandre Oliva <aoliva at redhat dot com>
- To: Richard Guenther <richard dot guenther at gmail dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Sun, 08 Nov 2009 22:29:38 -0200
- Subject: Re: fix -fcompare-debug regression in free_lang_data
- References: <orhbtzg4y5.fsf@livre.localdomain> <84fc9c000910160255o79c92bb8rfcf5d9a2be2eca86@mail.gmail.com> <or8wfacx8v.fsf@livre.localdomain> <84fc9c000910170420u32b61c0ag3b2c13446a763f6e@mail.gmail.com> <orws21hd89.fsf@livre.localdomain>
On Nov 8, 2009, Alexandre Oliva <aoliva@redhat.com> wrote:
> I see still a problem in Ada. Maybe it's not visible with the default
> bootstrap-debug BUILD_CONFIG, because the incorrect use of flag_gtoggle
> hides it, but it's noticeable if you compile with say ada/einfo.adb
> (among tens of others) with '-O2 -fcompare-debug=-g' (without any other
> -g).
Another -fcompare-debug problem is that free_lang_data_in_block()
removes types from BLOCK_VARSes, and decl uids go out of sync depending
on whether a function is inlined with or without this transformation.
Out-of-sync decl uids has been a great recipe for codegen differences,
so lto needs to fix this somehow.
This problem is visible compiling tree.c itself with -g
-fcompare-debug=-g0: it's when gimple_op gets inlined into
find_decls_types_in_node that decl uids go out of sync, because the
CONST_CAST-introduced union is not there in the -g0 compilation, and it
remains in place in the -g compilation.
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer