Ping.
> From: Hans-Peter Nilsson <h...@axis.com>
> Date: Wed, 4 Oct 2023 19:04:55 +0200
>
> > From: Hans-Peter Nilsson <h...@axis.com>
> > Date: Wed, 4 Oct 2023 17:15:28 +0200
>
> > New version coming up.
>
> Using pointer-sized int instead of int,
> __atomic_compare_exchange instead of __atomic_exchange,
> renamed to atomic-cmpxchg-word from atomic-exchange, and
> updating a comment that already seemed reasonably well
> placed.
>
> Tested as with v1 1/2.
>
> Ok to commit?
>
> -- >8 --
> Some targets (armv6-m) support inline atomic load and store,
> i.e. dg-require-thread-fence matches, but not atomic operations like
> compare and exchange.
>
> This directive can be used to replace uses of dg-require-thread-fence
> where an atomic operation is actually used.
>
> * testsuite/lib/dg-options.exp (dg-require-atomic-cmpxchg-word):
> New proc.
> * testsuite/lib/libstdc++.exp (check_v3_target_atomic_cmpxchg_word):
> Ditto.
> ---
> libstdc++-v3/testsuite/lib/dg-options.exp | 9 ++++++
> libstdc++-v3/testsuite/lib/libstdc++.exp | 37 +++++++++++++++++++++++
> 2 files changed, 46 insertions(+)
>
> diff --git a/libstdc++-v3/testsuite/lib/dg-options.exp
> b/libstdc++-v3/testsuite/lib/dg-options.exp
> index 84ad0c65330b..850442b6b7c1 100644
> --- a/libstdc++-v3/testsuite/lib/dg-options.exp
> +++ b/libstdc++-v3/testsuite/lib/dg-options.exp
> @@ -133,6 +133,15 @@ proc dg-require-thread-fence { args } {
> return
> }
>
> +proc dg-require-atomic-cmpxchg-word { args } {
> + if { ![ check_v3_target_atomic_cmpxchg_word ] } {
> + upvar dg-do-what dg-do-what
> + set dg-do-what [list [lindex ${dg-do-what} 0] "N" "P"]
> + return
> + }
> + return
> +}
> +
> proc dg-require-atomic-builtins { args } {
> if { ![ check_v3_target_atomic_builtins ] } {
> upvar dg-do-what dg-do-what
> diff --git a/libstdc++-v3/testsuite/lib/libstdc++.exp
> b/libstdc++-v3/testsuite/lib/libstdc++.exp
> index 608056e5068e..4bedb36dc6f9 100644
> --- a/libstdc++-v3/testsuite/lib/libstdc++.exp
> +++ b/libstdc++-v3/testsuite/lib/libstdc++.exp
> @@ -1221,6 +1221,43 @@ proc check_v3_target_thread_fence { } {
> }]
> }
>
> +proc check_v3_target_atomic_cmpxchg_word { } {
> + return [check_v3_target_prop_cached et_atomic_cmpxchg_word {
> + global cxxflags
> + global DEFAULT_CXXFLAGS
> +
> + # Set up and link a C++11 test program that depends on
> + # atomic-compare-exchange being available for a pointer-sized
> + # integer. It should be sufficient as gcc can derive all
> + # other operations when a target implements this operation.
> + set src atomic_cmpxchg_word[pid].cc
> +
> + set f [open $src "w"]
> + puts $f "
> + __UINTPTR_TYPE__ i, j, k;
> + int main() {
> + __atomic_compare_exchange (&i, &j, &k, 1, __ATOMIC_SEQ_CST,
> __ATOMIC_SEQ_CST);
> + return 0;
> + }"
> + close $f
> +
> + set cxxflags_saved $cxxflags
> + set cxxflags "$cxxflags $DEFAULT_CXXFLAGS -Werror -std=gnu++11"
> +
> + set lines [v3_target_compile $src /dev/null executable ""]
> + set cxxflags $cxxflags_saved
> + file delete $src
> +
> + if [string match "" $lines] {
> + # No error message, linking succeeded.
> + return 1
> + } else {
> + verbose "check_v3_target_atomic_cmpxchg_word: compilation failed" 2
> + return 0
> + }
> + }]
> +}
> +
> # Return 1 if atomics_bool and atomic_int are always lock-free, 0 otherwise.
> proc check_v3_target_atomic_builtins { } {
> return [check_v3_target_prop_cached et_atomic_builtins {
> --
> 2.30.2
>
