On Tue, Dec 16, 2025 at 1:36 PM Robin Dapp <[email protected]> wrote:
>
> Hi,
>
> In the process of refactoring the gather/scatter rework this likely got
> lost. In the "third pass" that we look for a configuration with a
> smaller scale and a larger offset type with the same signedness.
> We want to be able to multiply the offset by the new
> scale but not change the offset sign. What we actually checked is
> whether a converted offset type was supported without setting
> *supported_offset_vectype.
>
> This patch removes the check for the offset type change and replaces it
> with a TYPE_SIGN match.
>
> Bootstrapped and regtested on x86 and power10. Regtested on riscv64 and
> aarch64.
OK.
> Regards
> Robin
>
> PR tree-optimization/123118
>
> gcc/ChangeLog:
>
> * tree-vect-data-refs.cc (vect_gather_scatter_fn_p): Check that
> the type sign is equal.
>
> gcc/testsuite/ChangeLog:
>
> * g++.target/riscv/rvv/autovec/pr123118.C: New test.
> ---
> .../g++.target/riscv/rvv/autovec/pr123118.C | 19 +++++++++++++++++++
> gcc/tree-vect-data-refs.cc | 10 +++-------
> 2 files changed, 22 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/g++.target/riscv/rvv/autovec/pr123118.C
>
> diff --git a/gcc/testsuite/g++.target/riscv/rvv/autovec/pr123118.C
> b/gcc/testsuite/g++.target/riscv/rvv/autovec/pr123118.C
> new file mode 100644
> index 00000000000..8cef5a7fe91
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/riscv/rvv/autovec/pr123118.C
> @@ -0,0 +1,19 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -march=rv64gcv -mabi=lp64d" } */
> +
> +long long a;
> +short c, d;
> +extern int e[][1][1][1];
> +extern bool f[][1][4][2];
> +#include <vector>
> +
> +void
> +g ()
> +{
> + for (bool b;;)
> + for (signed char h (c); h < 4; h += -4487 - 119)
> + {
> + e[b][b][b][b] = std::max (std::min ((long long) 3, a), (long long) d);
> + f[0][0][h][1] = h;
> + }
> +}
> diff --git a/gcc/tree-vect-data-refs.cc b/gcc/tree-vect-data-refs.cc
> index b35ba05fd08..f12e1f6af5b 100644
> --- a/gcc/tree-vect-data-refs.cc
> +++ b/gcc/tree-vect-data-refs.cc
> @@ -4709,13 +4709,9 @@ vect_gather_scatter_fn_p (vec_info *vinfo, bool
> read_p, bool masked_p,
> unsigned int precision
> = TYPE_PRECISION (TREE_TYPE (configs[i].offset_vectype));
> if (configs[i].scale < scale
> - && precision >= needed_precision
> - && (supportable_convert_operation (CONVERT_EXPR,
> - configs[i].offset_vectype,
> - offset_vectype, &tmp)
> - || (needed_precision == offset_precision
> - && tree_nop_conversion_p (configs[i].offset_vectype,
> - offset_vectype))))
> + && TYPE_SIGN (configs[i].offset_vectype)
> + == TYPE_SIGN (offset_vectype)
> + && precision >= needed_precision)
> {
> *ifn_out = configs[i].ifn;
> *offset_vectype_out = configs[i].offset_vectype;
> --
> 2.51.1
>
