On Wed, Aug 9, 2023 at 8:19 PM Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> The following patch enables _BitInt support on x86-64, the only
> target which has _BitInt specified in psABI.
>
> 2023-08-09 Jakub Jelinek <ja...@redhat.com>
>
> PR c/102989
> * config/i386/i386.cc (classify_argument): Handle BITINT_TYPE.
> (ix86_bitint_type_info): New function.
> (TARGET_C_BITINT_TYPE_INFO): Redefine.
LGTM, with a nit.
Thanks,
Uros.
>
> --- gcc/config/i386/i386.cc.jj 2023-08-08 15:55:05.627176766 +0200
> +++ gcc/config/i386/i386.cc 2023-08-08 16:12:02.308940091 +0200
> @@ -2121,7 +2121,8 @@ classify_argument (machine_mode mode, co
> return 0;
> }
>
> - if (type && AGGREGATE_TYPE_P (type))
> + if (type && (AGGREGATE_TYPE_P (type)
> + || (TREE_CODE (type) == BITINT_TYPE && words > 1)))
> {
> int i;
> tree field;
> @@ -2270,6 +2271,14 @@ classify_argument (machine_mode mode, co
> }
> break;
>
> + case BITINT_TYPE:
> + /* _BitInt(N) for N > 64 is passed as structure containing
> + (N + 63) / 64 64-bit elements. */
> + if (words > 2)
> + return 0;
> + classes[0] = classes[1] = X86_64_INTEGER_CLASS;
> + return 2;
> +
> default:
> gcc_unreachable ();
> }
> @@ -24842,6 +24851,26 @@ ix86_get_excess_precision (enum excess_p
> return FLT_EVAL_METHOD_UNPREDICTABLE;
> }
>
> +/* Return true if _BitInt(N) is supported and fill details about it into
> + *INFO. */
The above comment should fit into one line.
> +bool
> +ix86_bitint_type_info (int n, struct bitint_info *info)
> +{
> + if (!TARGET_64BIT)
> + return false;
> + if (n <= 8)
> + info->limb_mode = QImode;
> + else if (n <= 16)
> + info->limb_mode = HImode;
> + else if (n <= 32)
> + info->limb_mode = SImode;
> + else
> + info->limb_mode = DImode;
> + info->big_endian = false;
> + info->extended = false;
> + return true;
> +}
> +
> /* Implement PUSH_ROUNDING. On 386, we have pushw instruction that
> decrements by exactly 2 no matter what the position was, there is no
> pushb.
>
> @@ -25446,6 +25475,8 @@ ix86_run_selftests (void)
>
> #undef TARGET_C_EXCESS_PRECISION
> #define TARGET_C_EXCESS_PRECISION ix86_get_excess_precision
> +#undef TARGET_C_BITINT_TYPE_INFO
> +#define TARGET_C_BITINT_TYPE_INFO ix86_bitint_type_info
> #undef TARGET_PROMOTE_PROTOTYPES
> #define TARGET_PROMOTE_PROTOTYPES hook_bool_const_tree_true
> #undef TARGET_PUSH_ARGUMENT
>
> Jakub
>
