From: Xi Ruoyao <xry111@xry111.site>
To: liuzhensong <liuzhensong@loongson.cn>, binutils@sourceware.org
Cc: WANG Xuerui <i.swmail@xen0n.name>, chenglulu@loongson.cn
Subject: Re: [PATCH] LoongArch: Use copy relocation for %pc_lo12 against external symbol
Date: Thu, 01 Sep 2022 09:41:17 +0800 [thread overview]
Message-ID: <d1089572e821cf1cdb6f7e69223bb32df2ec2a41.camel@xry111.site> (raw)
In-Reply-To: <e0fad4d1-cf0f-bae6-186c-ad6a3b601d03@loongson.cn>
On Thu, 2022-09-01 at 09:27 +0800, liuzhensong wrote:
> The R_LARCH_COPY is supported in older versions, we removed this
> feature and are not going to support.
Hmm, then for
extern int x;
int f() { return x; }
it will produce a GOT access. If x is in another TU but not in a shared
library, such a GOT access and the GOT entry is unneeded.
This will be really a pain for situations like building an OS kernel, or
with -static or -static-pie. Even for this simple example, there is no
way to tell "x" is not in a shared library (maybe, expect LTO or linker
relaxation, but IIRC LTO or relaxation do not *guarantee* to avoid the
GOT, just "try to" avoid the GOT).
So is there any serious reason forbidding us from using R_LARCH_COPY? Or
any options for this "unneeded GOT" issue?
--
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University
next prev parent reply other threads:[~2022-09-01 1:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-31 13:22 Xi Ruoyao
2022-08-31 13:41 ` Xi Ruoyao
2022-09-01 1:38 ` liuzhensong
2022-09-01 1:38 ` liuzhensong
2022-09-01 2:12 ` Xi Ruoyao
2022-09-01 2:31 ` liuzhensong
2022-09-01 2:31 ` liuzhensong
2022-09-01 1:27 ` liuzhensong
2022-09-01 1:27 ` liuzhensong
2022-09-01 1:41 ` Xi Ruoyao [this message]
2022-09-01 2:09 ` liuzhensong
2022-09-01 7:42 ` Fangrui Song
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