From: Fangrui Song <i@maskray.me>
To: binutils <binutils@sourceware.org>
Subject: Re: [MIPS] Can we have R_MIPS_PC64?
Date: Wed, 8 Jul 2020 22:23:17 -0700 [thread overview]
Message-ID: <20200709052317.ef5ff6bm6athgbs6@gmail.com> (raw)
In-Reply-To: <20200219042647.rw2fdnb7gbtbmzbz@google.com>
On 2020-02-18, Fangrui Song wrote:
>On 2020-02-17, Maciej W. Rozycki wrote:
>>On Sat, 8 Feb 2020, Fangrui Song wrote:
>>
>>>I hope someone can add back R_MIPS_PC64.
>>
>>You don't need R_MIPS_PC64. You can yield the same effect the usual
>>MIPS64 way, that is by composing R_MIPS_PC32 with R_MIPS_64 (similarly to
>>e.g. how R_MIPS_REL32 composes with R_MIPS_64).
>>
>>Of course the toolchain may not as it stands support this composition.
>>Feel free to post patches to take care of your use case.
>>
>>HTH,
>>
>> Maciej
>
>Thank you for your comments. Sorry that I cannot create a patch, as I know very little about MIPS.
>
>I raised these MIPS issues (including the recent DT_MIPS_XHASH
>https://sourceware.org/ml/binutils/2020-01/msg00451.html) not because I
>have anything to do with MIPS. I started the threads from the viewpoint
>of a toolchain maintainer.
>
>I noticed MIPS introduced complexity in a number of areas,
>where other architectures can share a simple common implementation.
>(It is weird that .quad foo - . is not representable on MIPS64.)
>
>For my own selfish purposes, I will be sad if someone wants to add some
>peculiar MIPS features (e.g. DT_MIPS_XHASH) to LLVM binary utilities or
>lld. I hope we can get rid of things like
>https://reviews.llvm.org/D72228 at some point.
>
>I hope someone can implement PC64, or something similar for MIPS.
Simon Atanasyan has implemented .quad foo-. via a chain of relocation
R_MIPS_PC32/R_MIPS_64/R_MIPS_NONE in LLVM's integrated assembler
(https://reviews.llvm.org/D80390 ). This will be available in LLVM/Clang 11.0.0
I created a feature request for GNU as:
https://sourceware.org/bugzilla/show_bug.cgi?id=26222
prev parent reply other threads:[~2020-07-09 5:23 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-05 7:19 Fangrui Song
2020-02-05 9:00 ` Andrew Pinski
2020-02-05 9:04 ` Andrew Pinski
2020-02-05 9:10 ` Andrew Pinski
2020-02-05 9:16 ` Andrew Pinski
2020-02-08 18:40 ` Fangrui Song
2020-02-17 18:07 ` Maciej W. Rozycki
2020-02-19 4:26 ` Fangrui Song
2020-07-09 5:23 ` Fangrui Song [this message]
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