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From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen)
To: Helmut Grohne <helmut@subdivi.de>,
	Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
	"debian-arm@lists.debian.org" <debian-arm@lists.debian.org>,
	arcml <linux-snps-arc@lists.infradead.org>,
	GNU C Library <libc-alpha@sourceware.org>,
	Vineet Gupta <vineetg76@gmail.com>,
	Claudiu Zissulescu <Claudiu.Zissulescu@synopsys.com>,
	Vineet Gupta <Vineet.Gupta1@synopsys.com>
Subject: Re: ARC rebootstrap prereq (was Re: switching ARC to 64-bit time_t )
Date: Thu, 26 Mar 2020 15:04:28 -0400	[thread overview]
Message-ID: <20200326190428.dxgq6vetirgq5ixy@csclub.uwaterloo.ca> (raw)
In-Reply-To: <20200326142836.GA24503@alf.mars>

On Thu, Mar 26, 2020 at 03:28:36PM +0100, Helmut Grohne wrote:
> One part of the question here is "why do we need libatomic-ops?". The
> answer to that is, because libgc uses it and libgc is used by e.g.  gcc,
> gnutls, guile, and make. Possibly, some of these could be built without
> libgc, but this is how they are packaged for Debian at present.  Package
> dependencies currently say that we need libatomic-ops.
> 
> The other part is "what is missing in libatomic-ops"? If you look at a
> more recent implementation, such as riscv, you see that it basically
> says "trust gcc". So I guess all you need here is an arc-specific
> implementation that says "gcc knows what it is doing, use its
> primitives".
> 
> Given sufficient work, I guess libatomic-ops could be removed in favour
> of using the gcc built-ins directly. Not sure whether that'd fly with
> libgc upstream though.
> 
> So no, this is not a stupid question. Thank you for asking.

The way I read the details on libatomic is that it provides functions
to implement the things a given architecture can't do with intrinsics
in gcc directly.  So on some architectures it does nothing and on others
it implements missing bits for atomic operations.

-- 
Len Sorensen

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  reply	other threads:[~2020-03-26 19:10 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1578824547.git.alistair.francis@wdc.com>
     [not found] ` <4e95f95966d8d7c6a8339160dc62d81c1f6a1bfb.1578824547.git.alistair.francis@wdc.com>
2020-02-12  0:14   ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Vineet Gupta
2020-02-12  0:14     ` Alistair Francis
2020-02-12  1:30       ` Joseph Myers
2020-02-14 22:39         ` Alistair Francis
2020-02-18 23:05           ` switching ARC to 64-bit time_t (Re: [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64) Vineet Gupta
2020-02-18 23:13             ` Joseph Myers
2020-02-19 23:09               ` Lukasz Majewski
2020-02-19 23:11             ` Lukasz Majewski
2020-02-20  8:31               ` Arnd Bergmann
2020-02-20  9:37                 ` Lukasz Majewski
2020-02-20 12:37                   ` Arnd Bergmann
2020-02-20 13:14                     ` Lukasz Majewski
2020-02-20 14:44                       ` Arnd Bergmann
2020-02-20 15:42                         ` Lukasz Majewski
2020-02-20 16:08                           ` Arnd Bergmann
2020-02-20 16:31                             ` Lukasz Majewski
2020-02-24  2:48                         ` Viresh Kumar
2020-02-21 19:56                     ` Alistair Francis
2020-02-22  8:42                   ` Arnd Bergmann
2020-02-24  9:00                     ` Lukasz Majewski
2020-02-24  9:46                       ` Andreas Schwab
2020-02-24 10:14                         ` Lukasz Majewski
2020-02-24 10:23                           ` Andreas Schwab
2020-02-24 10:36                             ` Lukasz Majewski
2020-02-24 10:42                               ` Andreas Schwab
2020-02-24 11:13                                 ` Lukasz Majewski
2020-02-24 12:41                                   ` Lukasz Majewski
2020-02-25  0:03                               ` Joseph Myers
2020-02-25 11:39                                 ` Lukasz Majewski
2020-02-25 14:36                                   ` Joseph Myers
2020-02-26 13:18                                     ` Lukasz Majewski
2020-02-26 14:48                                       ` Joseph Myers
2020-02-26 16:28                                         ` Lukasz Majewski
2020-02-25  9:03                       ` Arnd Bergmann
2020-02-20 16:27                 ` Helmut Grohne
2020-03-26  0:25                   ` ARC rebootstrap prereq (was Re: switching ARC to 64-bit time_t ) Vineet Gupta
2020-03-26  5:54                     ` Helmut Grohne
2020-03-26 11:51                       ` Alexey Brodkin
2020-03-26 12:24                         ` Helmut Grohne
2020-03-26 12:53                           ` Alexey Brodkin
2020-03-26 14:28                             ` Helmut Grohne
2020-03-26 19:04                               ` Lennart Sorensen [this message]
2020-08-26 14:39                       ` Vineet Gupta
2020-08-26 15:43                         ` Helmut Grohne
2020-08-26 21:16                           ` Aurelien Jarno
2021-02-24 20:17                             ` Vineet Gupta
2021-02-26  9:47                               ` Helmut Grohne
2021-02-26 15:58                                 ` Vineet Gupta
2021-08-21 17:36                             ` Aurelien Jarno
2020-02-12  1:42       ` [RFC v6 07/23] RISC-V: Use 64-bit time_t and off_t for RV32 and RV64 Vineet Gupta
2020-02-12 12:58         ` Arnd Bergmann
2020-02-19  0:56   ` Vineet Gupta
2020-02-19  1:03     ` Alistair Francis
2020-02-19  1:31       ` Vineet Gupta
2020-02-19  8:30         ` Andreas Schwab
2020-02-19 18:42           ` Vineet Gupta
2020-02-19 23:18             ` Lukasz Majewski
2020-02-20  0:26               ` Vineet Gupta
2020-02-20  0:46                 ` Joseph Myers
2020-02-20  8:24                   ` Arnd Bergmann
2020-02-20 10:28                     ` Lukasz Majewski
2020-02-20 14:14                     ` Joseph Myers

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