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From: "H.J. Lu" <hjl.tools@gmail.com>
To: Richard Henderson <rth@twiddle.net>
Cc: Andreas Krebbel <krebbel@linux.vnet.ibm.com>,
	David Miller <davem@davemloft.net>,
	aj@suse.com, 	libc-alpha@sourceware.org,
	Binutils <binutils@sourceware.org>
Subject: Re: [PATCH] S/390: Fix two issues with the IFUNC optimized mem* routines
Date: Sun, 02 Sep 2012 14:50:00 -0000	[thread overview]
Message-ID: <CAMe9rOpX6j=rcdtJwuL3XCmG+TrPxk01DkZ0MrxWzAMCy8Gd=g@mail.gmail.com> (raw)
In-Reply-To: <50427D29.1010205@twiddle.net>

On Sat, Sep 1, 2012 at 2:24 PM, Richard Henderson <rth@twiddle.net> wrote:
> On 2012-09-01 10:21, H.J. Lu wrote:
>> It may work for other targets.  But x86 doesn't have a relax
>> pass.  I believe doing it in size_dynamic_sections is more
>> sensible.
>
> It *should* have a relax pass.  Especially as that allows one

A relax pass won't work properly for x86 without some surgery
since lang_relax_sections is called after bfd_elf_size_dynamic_sections
which calls elf_x86_64_allocate_dynrelocs to allocate GOT entries
and dynamic relocations. After it is done, it is not to easy to undo
the damage.

> to turn it all off just in case a bug is encountered.
>

This is a separate issue.  X86 backends also optimize
TLS relocations.  Some compilers generate bad TLS
sequences which lead to corrupted output:

http://sourceware.org/bugzilla/show_bug.cgi?id=4928

But there is no way to turn off the TLS optimization.  It
will be nice to move disable_target_specific_optimizations
from command_line to link_info so that a backend
can check it.


-- 
H.J.

  reply	other threads:[~2012-09-02 14:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <503E009B.3080302@linux.vnet.ibm.com>
     [not found] ` <CAMe9rOrmiF3VZOBNvEbMV5jFNog1-_EoPoT9rHTUQFsANaSD8w@mail.gmail.com>
     [not found]   ` <503E3930.5040603@linux.vnet.ibm.com>
     [not found]     ` <20120829.125208.824114683359549094.davem@davemloft.net>
     [not found]       ` <503F14A3.8070801@linux.vnet.ibm.com>
     [not found]         ` <CAMe9rOozW=4q_a=nmNvbZhsXooRZ4opvTTNtq2WHcGSSd2ONOw@mail.gmail.com>
2012-08-31  1:10           ` H.J. Lu
2012-08-31 14:43             ` Richard Henderson
2012-08-31 19:16               ` H.J. Lu
2012-09-01 16:51                 ` Richard Henderson
2012-09-01 17:22                   ` H.J. Lu
2012-09-01 21:25                     ` Richard Henderson
2012-09-02 14:50                       ` H.J. Lu [this message]
2012-09-02 19:41                         ` Richard Henderson
2012-09-02 20:06                           ` H.J. Lu

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