Re: [PATCH] x86: Check invalid third argument to __builtin_ia32_prefetch

[Hongtao Liu <crazylht@gmail.com>]

On Thu, Jan 19, 2023 at 3:12 AM H.J. Lu via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> Check invalid third argument to __builtin_ia32_prefetch when expaning
> __builtin_ia32_prefetch to avoid ICE later.
Ok, thanks.
>
> gcc/
>
>         PR target/108436
>         * config/i386/i386-expand.cc (ix86_expand_builtin): Check
>         invalid third argument to __builtin_ia32_prefetch.
>
> gcc/testsuite/
>
>         * gcc.target/i386/pr108436.c: New test.
> ---
>  gcc/config/i386/i386-expand.cc           | 12 ++++++++++++
>  gcc/testsuite/gcc.target/i386/pr108436.c | 15 +++++++++++++++
>  2 files changed, 27 insertions(+)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr108436.c
>
> diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
> index 54f700cd09d..e2e2d28bb47 100644
> --- a/gcc/config/i386/i386-expand.cc
> +++ b/gcc/config/i386/i386-expand.cc
> @@ -13175,6 +13175,12 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
>
>         if (INTVAL (op3) == 1)
>           {
> +           if (INTVAL (op2) < 2 || INTVAL (op2) > 3)
> +             {
> +               error ("invalid third argument");
> +               return const0_rtx;
> +             }
> +
>             if (TARGET_64BIT && TARGET_PREFETCHI
>                 && local_func_symbolic_operand (op0, GET_MODE (op0)))
>               emit_insn (gen_prefetchi (op0, op2));
> @@ -13195,6 +13201,12 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
>                 op0 = copy_addr_to_reg (op0);
>               }
>
> +           if (INTVAL (op2) < 0 || INTVAL (op2) > 3)
> +             {
> +               warning (0, "invalid third argument to %<__builtin_ia32_prefetch%>; using zero");
> +               op2 = const0_rtx;
> +             }
> +
>             if (TARGET_3DNOW || TARGET_PREFETCH_SSE
>                 || TARGET_PRFCHW || TARGET_PREFETCHWT1)
>               emit_insn (gen_prefetch (op0, op1, op2));
> diff --git a/gcc/testsuite/gcc.target/i386/pr108436.c b/gcc/testsuite/gcc.target/i386/pr108436.c
> new file mode 100644
> index 00000000000..d51f25863a5
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr108436.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mprefetchi" } */
> +
> +int
> +foo (int a)
> +{
> +  return a + 1;
> +}
> +
> +void
> +bad (int *p)
> +{
> +  __builtin_ia32_prefetch (p, 0, 4, 0);   /* { dg-warning "invalid third argument to '__builtin_ia32_prefetch'; using zero" } */
> +  __builtin_ia32_prefetch (foo, 0, 4, 1);   /* { dg-error "invalid third argument" } */
> +}
> --
> 2.39.0
>


-- 
BR,
Hongtao