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| author | Alan Modra <amodra@gmail.com> | 2015-09-18 16:17:49 +0930 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2015-09-18 16:38:03 +0930 |
| commit | 7c9cf4158452094f4c463676e5122c5c4ce64de8 (patch) | |
| tree | 0ffa90631c601f42f7c88145c3faef48e8d6fdab /ld/ld.texinfo | |
| parent | 975f8a9e3144e4d3d3f391e907c8bf94b23dc8b6 (diff) | |
| download | gdb-7c9cf4158452094f4c463676e5122c5c4ce64de8.zip gdb-7c9cf4158452094f4c463676e5122c5c4ce64de8.tar.gz gdb-7c9cf4158452094f4c463676e5122c5c4ce64de8.tar.bz2 | |
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.
Diffstat (limited to 'ld/ld.texinfo')
| -rw-r--r-- | ld/ld.texinfo | 15 |
1 files changed, 15 insertions, 0 deletions
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 |