On Mon, Oct 28, 2024 at 12:41 AM Andrew Pinski <quic_apin...@quicinc.com> wrote:
>
> ABSU_EXPR lowering incorrectly used the resulting type
> for the new expression but in the case of ABSU the resulting
> type is an unsigned type and with ABSU is folded away. The fix
> is to use a signed type for the expression instead.
>
> Bootstrapped and tested on x86_64-linux-gnu.
OK.
> PR middle-end/111285
>
> gcc/ChangeLog:
>
> * tree-vect-generic.cc (do_unop): Use a signed type for the
> operand if the operation was ABSU_EXPR.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/torture/vect-absu-1.C: New test.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/testsuite/g++.dg/torture/vect-absu-1.C | 29 ++++++++++++++++++++++
> gcc/tree-vect-generic.cc | 10 +++++++-
> 2 files changed, 38 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/g++.dg/torture/vect-absu-1.C
>
> diff --git a/gcc/testsuite/g++.dg/torture/vect-absu-1.C
> b/gcc/testsuite/g++.dg/torture/vect-absu-1.C
> new file mode 100644
> index 00000000000..0b2035f638f
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/torture/vect-absu-1.C
> @@ -0,0 +1,29 @@
> +// { dg-do run }
> +// PR middle-end/111285
> +
> +// The lowering of vect absu was done incorrectly
> +
> +#define vect1 __attribute__((vector_size(sizeof(int))))
> +
> +#define negabs(a) a < 0 ? a : -a
> +
> +__attribute__((noinline))
> +int s(int a)
> +{
> + return negabs(a);
> +}
> +__attribute__((noinline))
> +vect1 int v(vect1 int a)
> +{
> + return negabs(a);
> +}
> +
> +int main(void)
> +{
> + for(int i = -10; i < 10; i++)
> + {
> + vect1 int t = {i};
> + if (v(t)[0] != s(i))
> + __builtin_abort();
> + }
> +}
> diff --git a/gcc/tree-vect-generic.cc b/gcc/tree-vect-generic.cc
> index ef7d2dd259d..21d906e9c55 100644
> --- a/gcc/tree-vect-generic.cc
> +++ b/gcc/tree-vect-generic.cc
> @@ -168,7 +168,15 @@ do_unop (gimple_stmt_iterator *gsi, tree inner_type,
> tree a,
> tree b ATTRIBUTE_UNUSED, tree bitpos, tree bitsize,
> enum tree_code code, tree type ATTRIBUTE_UNUSED)
> {
> - a = tree_vec_extract (gsi, inner_type, a, bitsize, bitpos);
> + tree rhs_type = inner_type;
> +
> + /* For ABSU_EXPR, use the signed type for the rhs if the rhs was signed. */
> + if (code == ABSU_EXPR
> + && ANY_INTEGRAL_TYPE_P (TREE_TYPE (a))
> + && !TYPE_UNSIGNED (TREE_TYPE (a)))
> + rhs_type = signed_type_for (rhs_type);
> +
> + a = tree_vec_extract (gsi, rhs_type, a, bitsize, bitpos);
> return gimplify_build1 (gsi, code, inner_type, a);
> }
>
> --
> 2.43.0
>
