On Sat, Aug 23, 2025 at 2:42 AM Sam James <s...@gentoo.org> wrote:
>
> Allow passing --with-tls= at configure-time to control the default value
> of -mtls-dialect= for i386 and x86_64. The default itself (gnu) is not changed
> unless --with-tls= is passed.
>
> --with-tls= is already wired up for ARM and RISC-V.
>
> gcc/ChangeLog:
> PR target/120933
>
> * config.gcc (supported_defaults): Add tls for i386, x86_64.
> * config/i386/i386.h (host_detect_local_cpu): Add tls.
> * doc/install.texi: Document --with-tls= for i386, x86_64.
OK.
Thanks,
Uros.
> ---
> Bootstrapped on x86_64-pc-linux-gnu. Testing in progress there and on
> i686-pc-linux-gnu. OK?
>
> gcc/config.gcc | 13 ++++++++++++-
> gcc/config/i386/i386.h | 3 ++-
> gcc/doc/install.texi | 3 +++
> 3 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/gcc/config.gcc b/gcc/config.gcc
> index db813a7b561c..04e88cce00d5 100644
> --- a/gcc/config.gcc
> +++ b/gcc/config.gcc
> @@ -4658,7 +4658,7 @@ case "${target}" in
> ;;
>
> i[34567]86-*-* | x86_64-*-*)
> - supported_defaults="abi arch arch_32 arch_64 cpu cpu_32
> cpu_64 tune tune_32 tune_64"
> + supported_defaults="abi arch arch_32 arch_64 cpu cpu_32
> cpu_64 tune tune_32 tune_64 tls"
> for which in arch arch_32 arch_64 cpu cpu_32 cpu_64 tune
> tune_32 tune_64; do
> eval "val=\$with_$which"
> case " $x86_archs " in
> @@ -4717,6 +4717,17 @@ case "${target}" in
> ;;
> esac
> done
> +
> + # Handle --with-tls.
> + case "$with_tls" in
> + ""|gnu|gnu2)
> + # OK
> + ;;
> + *)
> + echo "Unknown TLS method used in
> --with-tls=$with_tls" 1>&2
> + exit 1
> + ;;
> + esac
> ;;
>
> riscv*-*-*)
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> index 2fbc1f6e9826..2d53db683176 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -644,7 +644,8 @@ extern const char *host_detect_local_cpu (int argc, const
> char **argv);
> {"cpu_64", "%{" OPT_ARCH64
> ":%{!mtune=*:%{!mcpu=*:%{!march=*:-mtune=%(VALUE)}}}}" }, \
> {"arch", "%{!march=*:-march=%(VALUE)}"}, \
> {"arch_32", "%{" OPT_ARCH32 ":%{!march=*:-march=%(VALUE)}}"}, \
> - {"arch_64", "%{" OPT_ARCH64 ":%{!march=*:-march=%(VALUE)}}"},
> + {"arch_64", "%{" OPT_ARCH64 ":%{!march=*:-march=%(VALUE)}}"}, \
> + {"tls", "%{!mtls-dialect=*:-mtls-dialect=%(VALUE)}"},
>
> /* Specs for the compiler proper */
>
> diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
> index 74232247d8b7..6913035b5966 100644
> --- a/gcc/doc/install.texi
> +++ b/gcc/doc/install.texi
> @@ -1254,6 +1254,9 @@ descriptor-based dialect.
> For RISC-V targets, possible values for @var{dialect} are @code{trad} or
> @code{desc}, which select between the traditional GNU dialect and the GNU TLS
> descriptor-based dialect.
> +For i386, x86-64 targets, possible values for @var{dialect} are @code{gnu} or
> +@code{gnu2}, which select between the original GNU dialect and the GNU TLS
> +descriptor-based dialect.
>
> @item --enable-multiarch
> Specify whether to enable or disable multiarch support. The default is
> --
> 2.51.0
>
