Could you make a simple testcase that could vectorize two loops in
different modes (e.g one SI and one SF) and with this param will only
auto vec on loop?
On Wed, May 21, 2025 at 9:47 PM Robin Dapp <rdapp....@gmail.com> wrote:
>
> Hi,
>
> This patch adds a --param=autovec-mode=<MODE_NAME>. When the param is
> specified we make autovectorize_vector_modes return exactly this mode if
> it is available. This helps when testing different vectorizer settings.
>
> Regtested on rv64gcv_zvl512b.
>
> Regards
> Robin
>
> gcc/ChangeLog:
>
> * config/riscv/riscv-v.cc (autovectorize_vector_modes): Return
> user-specified mode if available.
> * config/riscv/riscv.opt: New param.
> ---
> gcc/config/riscv/riscv-v.cc | 20 ++++++++++++++++++++
> gcc/config/riscv/riscv.opt | 4 ++++
> 2 files changed, 24 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
> index 1b5ef51886e..a7f2f0a4abe 100644
> --- a/gcc/config/riscv/riscv-v.cc
> +++ b/gcc/config/riscv/riscv-v.cc
> @@ -2821,6 +2821,26 @@ autovectorize_vector_modes (vector_modes *modes, bool)
> i++;
> size = base_size / (1U << i);
> }
> +
> + /* If the user specified the exact mode to use look if it is available and
> + remove all other ones before returning. */
> + if (riscv_autovec_mode)
> + {
> + auto_vector_modes ms;
> + ms.safe_splice (*modes);
> + modes->truncate (0);
> +
> + for (machine_mode mode : ms)
> + {
> + if (!strcmp (GET_MODE_NAME (mode), riscv_autovec_mode))
> + {
> + modes->safe_push (mode);
> + return 0;
> + }
> + }
> + return 0;
> + }
> +
> /* Enable LOOP_VINFO comparison in COST model. */
> return VECT_COMPARE_COSTS;
> }
> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
> index 527e09549a8..5b6dbc6bb4e 100644
> --- a/gcc/config/riscv/riscv.opt
> +++ b/gcc/config/riscv/riscv.opt
> @@ -286,6 +286,10 @@ Max number of bytes to compare as part of inlined
> strcmp/strncmp routines (defau
> Target RejectNegative Joined UInteger Var(gpr2vr_cost)
> Init(GPR2VR_COST_UNPROVIDED)
> Set the cost value of the rvv instruction when operate from GPR to VR.
>
> +-param=autovec-mode=
> +Target Undocumented RejectNegative Joined Var(riscv_autovec_mode) Save
> +Set the only autovec mode to try.
> +
> Enum
> Name(rvv_max_lmul) Type(enum rvv_max_lmul_enum)
> The RVV possible LMUL (-mrvv-max-lmul=):
> --
> 2.49.0
>
