third_party/highway/hwy/per_target.h

// Copyright 2022 Google LLC
// SPDX-License-Identifier: Apache-2.0
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef HIGHWAY_HWY_PER_TARGET_H_
#define HIGHWAY_HWY_PER_TARGET_H_

#include <stddef.h>
#include <stdint.h>

#include "third_party/highway/hwy/highway_export.h"

// Functions to query the capabilities of the target that will be called by
// HWY_DYNAMIC_DISPATCH, which is not necessarily the current target.

namespace hwy {

// Returns the HWY_TARGET which HWY_DYNAMIC_DISPATCH selected.
HWY_DLLEXPORT int64_t DispatchedTarget();

// Returns size in bytes of a vector, i.e. `Lanes(ScalableTag<uint8_t>())`.
//
// Do not cache the result, which may change after calling DisableTargets, or
// if software requests a different vector size (e.g. when entering/exiting SME
// streaming mode). Instead call this right before the code that depends on the
// result, without any DisableTargets or SME transition in-between. Note that
// this involves an indirect call, so prefer not to call this frequently nor
// unnecessarily.
HWY_DLLEXPORT size_t VectorBytes();

// Returns whether 64-bit integers, 16/64-bit floats are a supported lane type.
HWY_DLLEXPORT bool HaveInteger64();
HWY_DLLEXPORT bool HaveFloat16();
HWY_DLLEXPORT bool HaveFloat64();

}  // namespace hwy

#endif  // HIGHWAY_HWY_PER_TARGET_H_