From: Cary Coutant <ccoutant@gmail.com>
To: Vladislav Khmelevsky <och95@yandex.ru>
Cc: Binutils <binutils@sourceware.org>
Subject: Re: [PATCH] gold/aarch64: Fix adrp distance check
Date: Fri, 29 Jul 2022 13:14:08 -0700 [thread overview]
Message-ID: <CAJimCsFaZnnHW9v6i4DgQxf_P7j5SUOJmp5i42AWwMXau5uVKw@mail.gmail.com> (raw)
In-Reply-To: <20220625175259.3171982-1-och95@yandex.ru>
> The offset between destination and location is a signed number,
> currently the offset is treated as unsigned number, thus mathematical
> shifting of negative value is performed incorrectly.
Do you have a test case to illustrate the problem?
+ int64_t offset
+ = static_cast<int64_t> (Reloc::Page (dest) - Reloc::Page (location));
+ int64_t adrp_imm = offset < 0 ? ~(~offset >> 12) : offset >> 12;
C++ conventions: No space before paren in a function call.
The cast is unnecessary here for assignment to an int64_t. Once the
result is in a signed int, I don't think you need to go to all that
extra trouble to shift it.
I'd suggest this instead:
int64_t adrp_imm = Reloc::Page(dest) - Reloc::Page(location);
adrp_imm >>= 12;
-cary
next prev parent reply other threads:[~2022-07-29 20:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-25 17:52 Vladislav Khmelevsky
2022-07-29 20:14 ` Cary Coutant [this message]
2022-07-29 20:44 ` Andreas Schwab
2022-07-29 22:14 ` Cary Coutant
2022-08-08 19:18 ` Vladislav Khmelevsky
2022-11-07 11:28 Vladislav Khmelevsky
2022-11-11 0:49 ` Cary Coutant
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