From: Jiong Wang <jiong.wang@arm.com>
To: Christophe Lyon <christophe.lyon@linaro.org>
Cc: Marcus Shawcroft <marcus.shawcroft@gmail.com>,
gcc-patches <gcc-patches@gnu.org>
Subject: Re: [AArch64][TLSLE][3/3] Implement local executable mode for all memory model
Date: Thu, 27 Aug 2015 09:53:00 -0000 [thread overview]
Message-ID: <n9961413w63.fsf@arm.com> (raw)
In-Reply-To: <CAKdteOZDnKhEaw6rACrv-vu6c3fwDh99=zCHiQ-DE_rhFd8Tew@mail.gmail.com>
Christophe Lyon writes:
> On 27 August 2015 at 10:35, Jiong Wang <jiong.wang@arm.com> wrote:
>>
>> Christophe Lyon writes:
>>
>>> On 19 August 2015 at 16:21, Jiong Wang <jiong.wang@arm.com> wrote:
>>>>
>>>> Marcus Shawcroft writes:
>>>>
>>>>> On 21 May 2015 at 17:49, Jiong Wang <jiong.wang@arm.com> wrote:
>>>>>
>>>>>> 2015-05-14 Jiong Wang <jiong.wang@arm.com>
>>>>>> gcc/
>>>>>> * config/aarch64/aarch64.c (aarch64_print_operand): Support tls_size.
>>>>>> * config/aarch64/aarch64.md (tlsle): Choose proper instruction
>>>>>> sequences.
>>>>>> (tlsle_<mode>): New define_insn.
>>>>>> (tlsle_movsym_<mode>): Ditto.
>>>>>> * config/aarch64/constraints.md (Uta): New constraint.
>>>>>> (Utb): Ditto.
>>>>>> (Utc): Ditto.
>>>>>> (Utd): Ditto.
>>>>>>
>>>>>> gcc/testsuite/
>>>>>> * gcc.target/aarch64/tlsle.c: New test source.
>>>>>> * gcc.target/aarch64/tlsle12.c: New testcase.
>>>>>> * gcc.target/aarch64/tlsle24.c: New testcase.
>>>>>> * gcc.target/aarch64/tlsle32.c: New testcase.
>>>>>>
>>>>>
>>>>>
>>>>> case SYMBOL_TLSLE:
>>>>> - asm_fprintf (asm_out_file, ":tprel_lo12_nc:");
>>>>> + if (aarch64_tls_size <= 12)
>>>>> + /* Make sure TLS offset fit into 12bit. */
>>>>> + asm_fprintf (asm_out_file, ":tprel_lo12:");
>>>>> + else
>>>>> + asm_fprintf (asm_out_file, ":tprel_lo12_nc:");
>>>>> break;
>>>>>
>>>>> Use the existing classify_symbol mechanism we use throughout the
>>>>> aarch64 backend. Specifically rename SYMBOL_TLSLE as SYMBOL_TLSLE24
>>>>> and introduce the 3 missing flavours then use the symbol
>>>>> classification to control behaviour such as this modifier selection.
>>>>
>>>> Done.
>>>>
>>>> classified TLS symbol into the following sub-types according to the value of tls size.
>>>>
>>>> SYMBOL_TLSLE12
>>>> SYMBOL_TLSLE24
>>>> SYMBOL_TLSLE32
>>>> SYMBOL_TLSLE48
>>>>
>>>> And On AArch64, instruction sequence for TLS LE under -mtls-size=32 will
>>>> utilize the relocation modifier "tprel_g0_nc" together with MOVK, it's
>>>> only supported in binutils since 2015-03-04 as PR gas/17843. So I
>>>> adjusted tlsle32.c to make it robust by detecting whether there is such
>>>> binutils support.
>>>>
>>>
>>> Hi,
>>>
>>> I'm (still) using binutils-2.25, and I can see that 2 of these new
>>> tests (tlsle12_1.c and tlsle24_1.c) fail at execution time on
>>> aarch64*-none-elf targets.
>>
>> Christophe,
>>
>> Those relocation types required by tls-size 12 & 24 are supported by
>> binutils-2.25 already, and you have passed compilation and failed at
>> exectuion, so there do have something wrong I guess.
>>
>> Either the generated instruction sequence or the bare-metal environment.
>>
>> One thing strange to me is those testcases are guarded by:
>>
>> /* { dg-require-effective-target tls_native } */
>>
>> while for bare-metal environment, normally you don't have tls_native
>> support right? then these testcases should have been marked as
>> unsupported otherwise they will generate native tls instruction
>> sequences while the bare-metal runtime environment may don't support
>> initialize tp register etc, thus caused the exectuion error.
>>
>> Could you please double check this? thanks
>>
>
> Well, the "tls_native" check passes (there is no "emutls" string in
> the generated assembly).
> This BTW, does not involve the binutils, since it only check the
> assembly output.
>
> Could it be a configure error instead? (where GCC wouldn't notice that
> it shouldn't generate such relocations)
to me, it's more like this. native tls is enabled on a no such support
platform.
I am trying to setup a bare-metal environment for reproducing. I was
testing on linux environment.
--
Regards,
Jiong
next prev parent reply other threads:[~2015-08-27 9:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-21 16:58 [AArch64][TLSLE][N/N] " Jiong Wang
2015-06-26 16:02 ` Marcus Shawcroft
2015-08-19 14:50 ` [AArch64][TLSLE][3/3] " Jiong Wang
2015-08-25 9:50 ` Marcus Shawcroft
2015-08-27 7:52 ` Christophe Lyon
2015-08-27 9:21 ` Jiong Wang
2015-08-27 9:41 ` Christophe Lyon
2015-08-27 9:53 ` Jiong Wang [this message]
2015-08-27 10:34 ` Jiong Wang
2015-08-27 13:23 ` Christophe Lyon
2015-08-27 13:36 ` Jiong Wang
2015-08-27 13:45 ` Christophe Lyon
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