On Fri, Jul 17, 2026 at 12:26:08PM +0000, Richard Earnshaw via Sourceware Forge
wrote:
> From: Richard Earnshaw <[email protected]>
>
> Arm has sunset the TME extension from the aarch64 architecture since
> there are no known implementations. Since this has been present in the
> compiler for a while though, we need to go through a deprecation cycle.
>
> This patch starts that process by:
> - removing it from the documentation
> - warning if the option is used during compilation
> - removing the tests for it.
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc (aarch64_override_options): Warn if
> +tme is used as an architecture feature
> (aarch64_process_target_attr): Similarly, but only if TME
> was previously disabled.
> * doc/invoke.texi (aarch64): Remove mentions of +tme.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/pragma_cpp_predefs_2.c: Drop tests for TME.
> * gcc.target/aarch64/acle/tme.c: Removed.
> * gcc.target/aarch64/acle/tme_guard-1.c: Removed.
> * gcc.target/aarch64/acle/tme_guard-2.c: Removed.
> * gcc.target/aarch64/acle/tme_guard-3.c: Removed.
> * gcc.target/aarch64/acle/tme_guard-4.c: Removed.
> ---
> gcc/config/aarch64/aarch64.cc | 10 +++++-
> gcc/doc/invoke.texi | 2 --
> gcc/testsuite/gcc.target/aarch64/acle/tme.c | 34 -------------------
> .../gcc.target/aarch64/acle/tme_guard-1.c | 9 -----
> .../gcc.target/aarch64/acle/tme_guard-2.c | 10 ------
> .../gcc.target/aarch64/acle/tme_guard-3.c | 9 -----
> .../gcc.target/aarch64/acle/tme_guard-4.c | 10 ------
> .../gcc.target/aarch64/pragma_cpp_predefs_2.c | 12 -------
> 8 files changed, 9 insertions(+), 87 deletions(-)
> delete mode 100644 gcc/testsuite/gcc.target/aarch64/acle/tme.c
> delete mode 100644 gcc/testsuite/gcc.target/aarch64/acle/tme_guard-1.c
> delete mode 100644 gcc/testsuite/gcc.target/aarch64/acle/tme_guard-2.c
> delete mode 100644 gcc/testsuite/gcc.target/aarch64/acle/tme_guard-3.c
> delete mode 100644 gcc/testsuite/gcc.target/aarch64/acle/tme_guard-4.c
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index a1f91dd425ef..2d34ee09b5be 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -20428,6 +20428,10 @@ aarch64_override_options (void)
> if (TARGET_ILP32)
> warning (OPT_Wdeprecated, "%<-mabi=ilp32%> is deprecated");
>
> + if (TARGET_TME)
> + warning (OPT_Wdeprecated,
> + "the architecture extension %<+tme%> is deprecated");
> +
> if (global_options.x_pcrelative_literal_loads == 1)
> warning (OPT_Wdeprecated, "%<-mpc-relative-literal-loads%> is
> deprecated");
>
> @@ -21078,6 +21082,11 @@ aarch64_process_target_attr (tree args)
> while (token)
> {
> num_attrs++;
> +
> + if ((strcmp (token, "+tme") == 0) && !TARGET_TME)
> + warning (OPT_Wdeprecated,
> + "the architecture extension %<+tme%> is deprecated");
> +
This check misses stuff like "+memtag+tme", and I think it's also in the wrong
place. The ideal place to check would probably be in aarch64_parse_extension;
if its use in the driver makes that difficult, then we should find some way of
passing the information out of that function to somewhere that can emit the
warning.
We could also use a global variable to ensure we only warn once about each
deprecated feature - if there's multiple instances, users can easily search the
code for "+tme" to find all of them.
Alice
> if (!aarch64_process_one_target_attr (token))
> {
> /* Check if token is possibly an arch extension without
> @@ -21094,7 +21103,6 @@ aarch64_process_target_attr (tree args)
> error ("pragma or attribute %<target(\"%s\")%> is not valid",
> token);
> return false;
> }
> -
> token = strtok_r (NULL, ",", &str_to_check);
> }
>
