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[binutils-gdb] Add PowerPC64 ld --tls-get-addr-optimize.
- From: Alan Modra <amodra at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 18 Sep 2015 07:26:12 -0000
- Subject: [binutils-gdb] Add PowerPC64 ld --tls-get-addr-optimize.
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7c9cf4158452094f4c463676e5122c5c4ce64de8
commit 7c9cf4158452094f4c463676e5122c5c4ce64de8
Author: Alan Modra <amodra@gmail.com>
Date: Fri Sep 18 16:17:49 2015 +0930
Add PowerPC64 ld --tls-get-addr-optimize.
Sometimes it may be of benefit to force use of the __tls_get_addr_opt
call stub even when the glibc being used during linking does not
advertise __tls_get_addr_opt.
bfd/
* elf64-ppc.h (struct ppc64_elf_params <tls_get_addr_opt>): Rename
from no_tls_get_addr_opt.
* elf64-ppc.c: Update for rename and inversion of tls_get_addr_opt.
(ppc64_elf_tls_setup): Set tls_get_addr_opt to 0 only when at
default of -1.
ld/
* emultempl/ppc64elf.em (params): Init tls_get_addr_opt field to -1.
(OPTION_TLS_GET_ADDR_OPT): Define.
(PARSE_AND_LIST_LONGOPTS): Handle --tls-get-addr-opt.
(PARSE_AND_LIST_OPTIONS, PARSE_AND_LIST_ARGS_CASES): Likewise.
* ld.texinfo: Document --tls-get-addr-optimize and
--no-tls-get-addr-optimize.
Diff:
---
bfd/ChangeLog | 8 ++++++++
bfd/elf64-ppc.c | 16 ++++++++--------
bfd/elf64-ppc.h | 2 +-
ld/ChangeLog | 9 +++++++++
ld/emultempl/ppc64elf.em | 17 +++++++++++++----
ld/ld.texinfo | 15 +++++++++++++++
6 files changed, 54 insertions(+), 13 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 26a0537..3e0c7b8 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2015-09-18 Alan Modra <amodra@gmail.com>
+
+ * elf64-ppc.h (struct ppc64_elf_params <tls_get_addr_opt>): Rename
+ from no_tls_get_addr_opt.
+ * elf64-ppc.c: Update for rename and inversion of tls_get_addr_opt.
+ (ppc64_elf_tls_setup): Set tls_get_addr_opt to 0 only when at
+ default of -1.
+
2015-09-17 Alan Modra <amodra@gmail.com>
PR 18867
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index f179f6d..5ad5f48 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -8136,7 +8136,7 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
htab->tls_get_addr_fd = ((struct ppc_link_hash_entry *)
elf_link_hash_lookup (&htab->elf, "__tls_get_addr",
FALSE, FALSE, TRUE));
- if (!htab->params->no_tls_get_addr_opt)
+ if (htab->params->tls_get_addr_opt)
{
struct elf_link_hash_entry *opt, *opt_fd, *tga, *tga_fd;
@@ -8203,8 +8203,8 @@ ppc64_elf_tls_setup (struct bfd_link_info *info)
}
}
}
- else
- htab->params->no_tls_get_addr_opt = TRUE;
+ else if (htab->params->tls_get_addr_opt < 0)
+ htab->params->tls_get_addr_opt = 0;
}
return _bfd_elf_tls_setup (info->output_bfd, info);
}
@@ -10125,7 +10125,7 @@ ppc64_elf_size_dynamic_sections (bfd *output_bfd,
return FALSE;
}
- tls_opt = (!htab->params->no_tls_get_addr_opt
+ tls_opt = (htab->params->tls_get_addr_opt
&& htab->tls_get_addr_fd != NULL
&& htab->tls_get_addr_fd->elf.plt.plist != NULL);
if (tls_opt || !htab->opd_abi)
@@ -10310,7 +10310,7 @@ plt_stub_size (struct ppc_link_hash_table *htab,
if (stub_entry->h != NULL
&& (stub_entry->h == htab->tls_get_addr_fd
|| stub_entry->h == htab->tls_get_addr)
- && !htab->params->no_tls_get_addr_opt)
+ && htab->params->tls_get_addr_opt)
size += 13 * 4;
return size;
}
@@ -10354,7 +10354,7 @@ build_plt_stub (struct ppc_link_hash_table *htab,
&& plt_thread_safe
&& !((stub_entry->h == htab->tls_get_addr_fd
|| stub_entry->h == htab->tls_get_addr)
- && !htab->params->no_tls_get_addr_opt))
+ && htab->params->tls_get_addr_opt))
{
bfd_vma pltoff = stub_entry->plt_ent->plt.offset & ~1;
bfd_vma pltindex = ((pltoff - PLT_INITIAL_ENTRY_SIZE (htab))
@@ -11005,7 +11005,7 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (stub_entry->h != NULL
&& (stub_entry->h == htab->tls_get_addr_fd
|| stub_entry->h == htab->tls_get_addr)
- && !htab->params->no_tls_get_addr_opt)
+ && htab->params->tls_get_addr_opt)
p = build_tls_get_addr_stub (htab, stub_entry, loc, off, r);
else
p = build_plt_stub (htab, stub_entry, loc, off, r);
@@ -13911,7 +13911,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
if (h != NULL
&& (h == htab->tls_get_addr_fd
|| h == htab->tls_get_addr)
- && !htab->params->no_tls_get_addr_opt)
+ && htab->params->tls_get_addr_opt)
{
/* Special stub used, leave nop alone. */
}
diff --git a/bfd/elf64-ppc.h b/bfd/elf64-ppc.h
index 19f72b5..d035ffc 100644
--- a/bfd/elf64-ppc.h
+++ b/bfd/elf64-ppc.h
@@ -34,7 +34,7 @@ struct ppc64_elf_params
bfd_signed_vma group_size;
/* Whether to use a special call stub for __tls_get_addr. */
- int no_tls_get_addr_opt;
+ int tls_get_addr_opt;
/* Whether to allow multiple toc sections. */
int no_multi_toc;
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 96359f5..f495ed2 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,14 @@
2015-09-18 Alan Modra <amodra@gmail.com>
+ * emultempl/ppc64elf.em (params): Init tls_get_addr_opt field to -1.
+ (OPTION_TLS_GET_ADDR_OPT): Define.
+ (PARSE_AND_LIST_LONGOPTS): Handle --tls-get-addr-opt.
+ (PARSE_AND_LIST_OPTIONS, PARSE_AND_LIST_ARGS_CASES): Likewise.
+ * ld.texinfo: Document --tls-get-addr-optimize and
+ --no-tls-get-addr-optimize.
+
+2015-09-18 Alan Modra <amodra@gmail.com>
+
PR ld/18963
* ldexp.h (struct ldexp_control): Add rel_from_abs.
(ldexp_finalize_syms): Declare.
diff --git a/ld/emultempl/ppc64elf.em b/ld/emultempl/ppc64elf.em
index 41942f9..08bd5d4 100644
--- a/ld/emultempl/ppc64elf.em
+++ b/ld/emultempl/ppc64elf.em
@@ -37,7 +37,7 @@ static void ppc_layout_sections_again (void);
static struct ppc64_elf_params params = { NULL,
&ppc_add_stub_section,
&ppc_layout_sections_again,
- 1, 0, 0,
+ 1, -1, 0,
${DEFAULT_PLT_STATIC_CHAIN-0}, -1, 0,
0, -1, -1, 0};
@@ -699,7 +699,8 @@ PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
#define OPTION_DOTSYMS (OPTION_NO_SAVRES + 1)
#define OPTION_NO_DOTSYMS (OPTION_DOTSYMS + 1)
#define OPTION_NO_TLS_OPT (OPTION_NO_DOTSYMS + 1)
-#define OPTION_NO_TLS_GET_ADDR_OPT (OPTION_NO_TLS_OPT + 1)
+#define OPTION_TLS_GET_ADDR_OPT (OPTION_NO_TLS_OPT + 1)
+#define OPTION_NO_TLS_GET_ADDR_OPT (OPTION_TLS_GET_ADDR_OPT + 1)
#define OPTION_NO_OPD_OPT (OPTION_NO_TLS_GET_ADDR_OPT + 1)
#define OPTION_NO_TOC_OPT (OPTION_NO_OPD_OPT + 1)
#define OPTION_NO_MULTI_TOC (OPTION_NO_TOC_OPT + 1)
@@ -722,6 +723,7 @@ PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
{ "save-restore-funcs", no_argument, NULL, OPTION_SAVRES },
{ "no-save-restore-funcs", no_argument, NULL, OPTION_NO_SAVRES },
{ "no-tls-optimize", no_argument, NULL, OPTION_NO_TLS_OPT },
+ { "tls-get-addr-optimize", no_argument, NULL, OPTION_TLS_GET_ADDR_OPT },
{ "no-tls-get-addr-optimize", no_argument, NULL, OPTION_NO_TLS_GET_ADDR_OPT },
{ "no-opd-optimize", no_argument, NULL, OPTION_NO_OPD_OPT },
{ "no-toc-optimize", no_argument, NULL, OPTION_NO_TOC_OPT },
@@ -786,6 +788,9 @@ PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
--no-tls-optimize Don'\''t try to optimize TLS accesses.\n"
));
fprintf (file, _("\
+ --tls-get-addr-optimize Force use of special __tls_get_addr call.\n"
+ ));
+ fprintf (file, _("\
--no-tls-get-addr-optimize Don'\''t use a special __tls_get_addr call.\n"
));
fprintf (file, _("\
@@ -877,8 +882,12 @@ PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
no_tls_opt = 1;
break;
+ case OPTION_TLS_GET_ADDR_OPT:
+ params.tls_get_addr_opt = 1;
+ break;
+
case OPTION_NO_TLS_GET_ADDR_OPT:
- params.no_tls_get_addr_opt = 1;
+ params.tls_get_addr_opt = 0;
break;
case OPTION_NO_OPD_OPT:
@@ -903,7 +912,7 @@ PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
case OPTION_TRADITIONAL_FORMAT:
no_tls_opt = 1;
- params.no_tls_get_addr_opt = 1;
+ params.tls_get_addr_opt = 0;
no_opd_opt = 1;
no_toc_opt = 1;
params.no_multi_toc = 1;
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index be1d490..57f1730 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -7133,6 +7133,21 @@ PowerPC64 @command{ld} normally performs some optimization of code
sequences used to access Thread-Local Storage. Use this option to
disable the optimization.
+@cindex PowerPC64 __tls_get_addr optimization
+@kindex --tls-get-addr-optimize
+@kindex --no-tls-get-addr-optimize
+@item --tls-get-addr-optimize, --no-tls-get-addr-optimize
+These options control whether PowerPC64 @command{ld} uses a special
+stub to call __tls_get_addr. PowerPC64 glibc 2.22 and later support
+an optimization that allows the second and subsequent calls to
+@code{__tls_get_addr} for a given symbol to be resolved by the special
+stub without calling in to glibc. By default the linker enables this
+option when glibc advertises the availability of __tls_get_addr_opt.
+Forcing this option on when using an older glibc won't do much besides
+slow down your applications, but may be useful if linking an
+application against an older glibc with the expectation that it will
+normally be used on systems having a newer glibc.
+
@cindex PowerPC64 OPD optimization
@kindex --no-opd-optimize
@item --no-opd-optimize