> Am 21.09.2023 um 05:10 schrieb Jiufu Guo <guoji...@linux.ibm.com>:
>
> Hi,
>
> The root cause of PR111355 and PR111482 is missing to check if vr0
> is undefined_p before call vr0.lower_bound.
>
> In the pattern "(X + C) / N",
>
> (if (INTEGRAL_TYPE_P (type)
> && get_range_query (cfun)->range_of_expr (vr0, @0))
> (if (...)
> (plus (op @0 @2) { wide_int_to_tree (type, plus_op1 (c)); })
> (if (TYPE_UNSIGNED (type) && c.sign_mask () < 0 ...
> && wi::geu_p (vr0.lower_bound (), -c))
>
> In "(if (...)", there is code to prevent vr0's undefined_p,
> But in the "else" part, vr0's undefined_p is not checked before
> "wi::geu_p (vr0.lower_bound (), -c)".
>
> Bootstrap & regtest pass on ppc64{,le}.
> Is this ok for trunk?
Ok
Richard
> BR,
> Jeff (Jiufu Guo)
>
>
> PR tree-optimization/111355
>
> gcc/ChangeLog:
>
> * match.pd ((X + C) / N): Update pattern.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/pr111355.c: New test.
>
> ---
> gcc/match.pd | 2 +-
> gcc/testsuite/gcc.dg/pr111355.c | 8 ++++++++
> 2 files changed, 9 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.dg/pr111355.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 39c9c81966a..5fdfba14d47 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1033,7 +1033,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> || (vr0.nonnegative_p () && vr3.nonnegative_p ())
> || (vr0.nonpositive_p () && vr3.nonpositive_p ())))
> (plus (op @0 @2) { wide_int_to_tree (type, plus_op1 (c)); })
> - (if (TYPE_UNSIGNED (type) && c.sign_mask () < 0
> + (if (!vr0.undefined_p () && TYPE_UNSIGNED (type) && c.sign_mask () < 0
> && exact_mod (-c)
> /* unsigned "X-(-C)" doesn't underflow. */
> && wi::geu_p (vr0.lower_bound (), -c))
> diff --git a/gcc/testsuite/gcc.dg/pr111355.c b/gcc/testsuite/gcc.dg/pr111355.c
> new file mode 100644
> index 00000000000..8bacbc69d31
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr111355.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -Wno-div-by-zero" } */
> +
> +/* Make sure no ICE. */
> +int main() {
> + unsigned b;
> + return b ? 1 << --b / 0 : 0;
> +}
> --
> 2.25.1
>
