On Wed, Jun 24, 2026 at 7:37 PM Oleg Tolmatcev <[email protected]> wrote:
>
> Match Clang's declaration of _m_prefetchw to avoid requiring
> const_cast<void *> at call sites.
>
> gcc/ChangeLog:
>
> * config/i386/prfchwintrin.h (_m_prefetchw):: Take
> volatile const void * instead of void *.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/prfchw-Wcast-qual-1.c: New test.
>
> Signed-off-by: oltolm <[email protected]>
OK and pushed.
Thanks,
Uros.
> ---
>
> I don't have git commit rights.
>
> Oleg
>
> gcc/config/i386/prfchwintrin.h | 4 ++--
> .../gcc.target/i386/prfchw-Wcast-qual-1.c | 16 ++++++++++++++++
> 2 files changed, 18 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
>
> diff --git a/gcc/config/i386/prfchwintrin.h b/gcc/config/i386/prfchwintrin.h
> index af3bded18e0..2ac190964de 100644
> --- a/gcc/config/i386/prfchwintrin.h
> +++ b/gcc/config/i386/prfchwintrin.h
> @@ -29,9 +29,9 @@
> #define _PRFCHWINTRIN_H_INCLUDED
>
> extern __inline void __attribute__((__gnu_inline__, __always_inline__,
> __artificial__))
> -_m_prefetchw (void *__P)
> +_m_prefetchw (volatile const void *__P)
> {
> - __builtin_prefetch (__P, 1, 3 /* _MM_HINT_T0 */);
> + __builtin_prefetch ((const void *) __P, 1, 3 /* _MM_HINT_T0 */);
> }
>
> #endif /* _PRFCHWINTRIN_H_INCLUDED */
> diff --git a/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
> b/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
> new file mode 100644
> index 00000000000..c6e86aa6d3d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/prfchw-Wcast-qual-1.c
> @@ -0,0 +1,16 @@
> +/* Verify that _m_prefetchw does not produce -Wcast-qual warnings when
> + included as a system header. The cast (const void *) drops volatile
> + from volatile const void *, which would trigger -Wcast-qual if not
> + in a system header. */
> +/* { dg-do compile } */
> +/* { dg-options "-mprfchw -O2 -Wcast-qual" } */
> +
> +#include <x86intrin.h>
> +
> +void
> +prefetchw_cast_qual_test (volatile void *p)
> +{
> + _m_prefetchw (p);
> +}
> +
> +/* { dg-bogus "cast discards .volatile. qualifier" "" { target *-*-* } 0 } */
> --
> 2.54.0.windows.1
>
