third_party/highway/hwy/per_target.h

   1 // Copyright 2022 Google LLC
   2 // SPDX-License-Identifier: Apache-2.0
   3 //
   4 // Licensed under the Apache License, Version 2.0 (the "License");
   5 // you may not use this file except in compliance with the License.
   6 // You may obtain a copy of the License at
   7 //
   8 //      http://www.apache.org/licenses/LICENSE-2.0
   9 //
  10 // Unless required by applicable law or agreed to in writing, software
  11 // distributed under the License is distributed on an "AS IS" BASIS,
  12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 // See the License for the specific language governing permissions and
  14 // limitations under the License.
  15
  16 #ifndef HIGHWAY_HWY_PER_TARGET_H_
  17 #define HIGHWAY_HWY_PER_TARGET_H_
  18
  19 #include <stddef.h>
  20
  21 // Per-target functions.
  22
  23 namespace hwy {
  24
  25 // Returns size in bytes of a vector, i.e. `Lanes(ScalableTag<uint8_t>())`.
  26 //
  27 // Do not cache the result, which may change after calling DisableTargets, or
  28 // if software requests a different vector size (e.g. when entering/exiting SME
  29 // streaming mode). Instead call this right before the code that depends on the
  30 // result, without any DisableTargets or SME transition in-between. Note that
  31 // this involves an indirect call, so prefer not to call this frequently nor
  32 // unnecessarily.
  33 size_t VectorBytes();
  34
  35 }  // namespace hwy
  36
  37 #endif  // HIGHWAY_HWY_PER_TARGET_H_