On Fri, Nov 22, 2024 at 09:56:17AM +0100, Jakub Jelinek wrote:
> Hi!
>
> Sorry, the last patch only partially fixed the __sync_* ICEs with
> _BitInt(128) on ia32.
> Even for !fetch we need to error out and return 0. I was afraid of
> APIs like __atomic_exchange/__atomic_compare_exchange, those obviously
> need to be supported even on _BitInt(128) on ia32, but they actually never
> sync_resolve_size, they are handled by adding the size argument and using
> the library version much earlier.
> For fetch && !orig_format (i.e. __atomic_fetch_* etc.) we need to return -1
> so that we handle it with a manualy __atomic_load +
> __atomic_compare_exchange loop in the caller, all other cases should
> be rejected.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok, thanks.
> 2024-11-22 Jakub Jelinek <ja...@redhat.com>
>
> PR c/117641
> * c-common.cc (sync_resolve_size): For size 16 with _BitInt
> on targets where TImode isn't supported, use goto incompatible if
> !fetch.
>
> * gcc.dg/bitint-117.c: New test.
>
> --- gcc/c-family/c-common.cc.jj 2024-11-19 20:35:53.222455518 +0100
> +++ gcc/c-family/c-common.cc 2024-11-21 11:23:07.897995741 +0100
> @@ -7457,11 +7457,10 @@ sync_resolve_size (tree function, vec<tr
>
> size = tree_to_uhwi (TYPE_SIZE_UNIT (type));
> if (size == 16
> - && fetch
> && TREE_CODE (type) == BITINT_TYPE
> && !targetm.scalar_mode_supported_p (TImode))
> {
> - if (!orig_format)
> + if (fetch && !orig_format)
> return -1;
> goto incompatible;
> }
> --- gcc/testsuite/gcc.dg/bitint-117.c.jj 2024-11-21 11:23:59.720260255
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-117.c 2024-11-21 11:24:59.141416996 +0100
> @@ -0,0 +1,13 @@
> +/* PR c/117641 */
> +/* { dg-do compile { target bitint575 } } */
> +/* { dg-options "-std=c23" } */
> +
> +void
> +foo (_BitInt(128) *b)
> +{
> + __sync_add_and_fetch (b, 1); /* { dg-error
> "incompatible" "" { target { ! int128 } } } */
> + __sync_val_compare_and_swap (b, 0, 1); /* { dg-error "incompatible" ""
> { target { ! int128 } } } */
> + __sync_bool_compare_and_swap (b, 0, 1); /* { dg-error "incompatible" ""
> { target { ! int128 } } } */
> + __sync_lock_test_and_set (b, 1); /* { dg-error "incompatible" ""
> { target { ! int128 } } } */
> + __sync_lock_release (b); /* { dg-error "incompatible" ""
> { target { ! int128 } } } */
> +}
>
> Jakub
>
Marek
