From: Joseph Myers <joseph@codesourcery.com>
To: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org, libc-alpha@sourceware.org
Subject: Re: [PATCH v4 02/15] ARC: ABI Implementation
Date: Thu, 26 Mar 2020 01:52:49 +0000 [thread overview]
Message-ID: <alpine.DEB.2.21.2003260138130.31593@digraph.polyomino.org.uk> (raw)
In-Reply-To: <20200313030419.15843-3-vgupta@synopsys.com>
On Thu, 12 Mar 2020, Vineet Gupta via Libc-alpha wrote:
> diff --git a/sysdeps/arc/bits/endianness.h b/sysdeps/arc/bits/endianness.h
> new file mode 100644
> index 000000000000..8f17ca84b485
> --- /dev/null
> +++ b/sysdeps/arc/bits/endianness.h
> @@ -0,0 +1,15 @@
> +#ifndef _BITS_ENDIANNESS_H
> +#define _BITS_ENDIANNESS_H 1
> +
> +#ifndef _BITS_ENDIAN_H
> +# error "Never use <bits/endian.h> directly; include <endian.h> instead."
> +#endif
> +
> +/* ARC has selectable endianness. */
> +#ifdef __BIG_ENDIAN__
> +# define __BYTE_ORDER __BIG_ENDIAN
> +#else
> +# define __BYTE_ORDER __LITTLE_ENDIAN
> +#endif
Elsewhere you say the port is little-endian only. In such cases we
generally have an error somewhere if you attempt to build glibc for the
other endianness, to avoid an other-endian configuration accidentally
building but not working and having a broken ABI. For example, see what
Nios II does: sysdeps/nios2/bits/endianness.h handles both endiannesses,
but sysdeps/nios2/configure.ac produces an error for big-endian.
> +/* PLT jump into resolver passes PC of PLTn, while _dl_fixup expects the
> + address of corresponding .rela.plt entry. */
> +
> +#ifdef __A7__
> +# define ARC_PLT_SIZE 12
> +#else
> +# define ARC_PLT_SIZE 16
> +#endif
Is this some sort of ABI difference between two incompatible ABIs? (The
ABI document you pointed to only seems to mention 12-byte PLT entries.)
> +#define reloc_index \
> +({ \
> + unsigned long int plt0 = D_PTR (l, l_info[DT_PLTGOT]); \
> + unsigned long int pltn = reloc_arg; \
> + /* Exclude PL0 and PLT1. */ \
Should PL0 be PLT0 here?
> + unsigned long int idx = (pltn - plt0)/ARC_PLT_SIZE - 2; \
Missing spaces around '/'.
> diff --git a/sysdeps/arc/gmp-mparam.h b/sysdeps/arc/gmp-mparam.h
> new file mode 100644
> index 000000000000..5580551483c8
> --- /dev/null
> +++ b/sysdeps/arc/gmp-mparam.h
> @@ -0,0 +1,23 @@
> +/* gmp-mparam.h -- Compiler/machine parameter header file.
> +
> +Copyright (C) 2017-2020 Free Software Foundation, Inc.
> +
> +This file is part of the GNU MP Library.
> +
> +The GNU MP Library is free software; you can redistribute it and/or modify
> +it under the terms of the GNU Lesser General Public License as published by
> +the Free Software Foundation; either version 2.1 of the License, or (at your
> +option) any later version.
> +
> +The GNU MP Library is distributed in the hope that it will be useful, but
> +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
> +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
> +License for more details.
> +
> +You should have received a copy of the GNU Lesser General Public License
> +along with the GNU MP Library; see the file COPYING.LIB. If not, see
> +<https://www.gnu.org/licenses/>. */
> +
> +#include <sysdeps/generic/gmp-mparam.h>
> +
> +#define IEEE_DOUBLE_BIG_ENDIAN 0
Plenty of architectures that have, or support, little-endian floating
point do not have gmp-mparam.h at all. IEEE_DOUBLE_BIG_ENDIAN is only
used to define union ieee_double_extract, which is nowhere used in glibc.
So I don't think you need this header at all (and it shows up the scope
for a more general cleanup possible for other ports, I suspect only the
x32 and mips64 versions of this header, the ones that define
_LONG_LONG_LIMB for ILP32 configurations with 64-bit registers, are the
only non-generic ones that do anything useful - but you don't need to do
that cleanup).
--
Joseph S. Myers
joseph@codesourcery.com
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc
next prev parent reply other threads:[~2020-03-26 1:53 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-13 3:04 [PATCH v4 00/15] glibc port to ARC processors Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 01/15] ARC: add definitions to elf/elf.h Vineet Gupta
2020-03-26 1:37 ` Joseph Myers
2020-03-26 1:52 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 02/15] ARC: ABI Implementation Vineet Gupta
2020-03-26 1:52 ` Joseph Myers [this message]
2020-03-26 2:39 ` Vineet Gupta
2020-03-26 18:48 ` Joseph Myers
2020-03-27 0:37 ` Vineet Gupta
2020-03-27 23:33 ` Vineet Gupta
2020-03-27 23:35 ` Joseph Myers
2020-03-27 23:47 ` Vineet Gupta
2020-03-31 21:08 ` Big Endian support as multi-ABI (was Re: [PATCH v4 02/15] ARC: ABI Implementation) Vineet Gupta
2020-03-31 21:27 ` Joseph Myers
2020-03-31 21:35 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 03/15] ARC: startup and dynamic linking code Vineet Gupta
2020-03-26 1:55 ` Joseph Myers
2020-03-26 2:45 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 04/15] ARC: Thread Local Storage support Vineet Gupta
2020-03-26 1:57 ` Joseph Myers
2020-03-26 2:47 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 05/15] ARC: Atomics and Locking primitives Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 06/15] ARC: math soft float support Vineet Gupta
2020-03-26 1:59 ` Joseph Myers
2020-03-26 2:48 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 07/15] ARC: hardware floating point support Vineet Gupta
2020-03-26 2:06 ` Joseph Myers
2020-03-26 3:19 ` Vineet Gupta
2020-03-26 23:22 ` Joseph Myers
2020-03-27 1:50 ` Vineet Gupta
2020-03-27 18:37 ` Joseph Myers
2020-03-27 18:53 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 08/15] ARC: Linux Syscall Interface Vineet Gupta
2020-03-26 23:52 ` Joseph Myers
2020-03-27 4:34 ` Vineet Gupta
2020-03-27 18:38 ` Joseph Myers
2020-03-13 3:04 ` [PATCH v4 09/15] ARC: Linux ABI Vineet Gupta
2020-03-27 0:38 ` Joseph Myers
2020-03-27 4:45 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 10/15] ARC: Linux Startup and Dynamic Loading Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 11/15] ARC: ABI lists Vineet Gupta
2020-03-27 0:40 ` Joseph Myers
2020-03-27 4:36 ` Vineet Gupta
2020-03-27 18:39 ` Joseph Myers
2020-03-27 19:09 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 12/15] ARC: Update syscall-names.list for ARC specific syscalls Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 13/15] ARC: Build Infrastructure Vineet Gupta
2020-03-27 22:47 ` Joseph Myers
2020-03-28 6:42 ` Vineet Gupta
2020-03-31 22:02 ` Vineet Gupta
2020-03-31 22:48 ` Joseph Myers
2020-04-01 0:44 ` __syscall_error (was Re: [PATCH v4 13/15] ARC: Build Infrastructure) Vineet Gupta
2020-04-01 7:58 ` Andreas Schwab
2020-04-01 21:38 ` Vineet Gupta
2020-04-01 17:06 ` Joseph Myers
2020-04-02 0:00 ` Vineet Gupta
2020-04-02 8:50 ` Florian Weimer
2020-04-02 20:22 ` Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 14/15] build-many-glibcs.py: Enable ARC builds Vineet Gupta
2020-03-13 3:04 ` [PATCH v4 15/15] Documentation for ARC port Vineet Gupta
2020-03-27 22:49 ` Joseph Myers
2020-03-27 23:56 ` Vineet Gupta
2020-03-28 0:01 ` Joseph Myers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.21.2003260138130.31593@digraph.polyomino.org.uk \
--to=joseph@codesourcery.com \
--cc=Vineet.Gupta1@synopsys.com \
--cc=libc-alpha@sourceware.org \
--cc=linux-snps-arc@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).