On Thu, Jun 16, 2022 at 02:22:09PM -0700, Chang S. Bae wrote:
> + 1. **Check the feature availability**. AMX_TILE is enumerated in CPUID
> + leaf 7, sub-leaf 0, bit 24 of EDX. If available, ``/proc/cpuinfo``
> + shows ``amx_tile`` in the flag entry of the CPUs. Given that, the
> + kernel may have set XSTATE component 18 in the XCR0 register. But a
> + user needs to ensure the kernel support via the ARCH_GET_XCOMP_SUPP
> + option::
> +
> + #include <asm/prctl.h>
> + #include <sys/syscall.h>
> + #include <stdio.h>
> + #include <unistd.h>
> +
> + #define ARCH_GET_XCOMP_SUPP 0x1021
> +
> + #define XFEATURE_XTILECFG 17
> + #define XFEATURE_XTILEDATA 18
> + #define XFEATURE_MASK_XTILE ((1 << XFEATURE_XTILECFG) | (1 << XFEATURE_XFILEDATA))
> +
> + unsigned long features;
> + long rc;
> +
> + ...
> +
> + rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_SUPP, &features);
> +
> + if (!rc && features & XFEATURE_MASK_XTILE == XFEATURE_MASK_XTILE)
> + printf("AMX is available.\n");
> +
nit: stdio include line isn't aligned with the rest of code.
Otherwise LGTM (no new warnings).
Reviewed-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>
--
An old man doll... just what I always wanted! - Clara
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