// Copyright 2022 Risc0, Inc.
//
// 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.

PARALLEL_KERNEL(                                  //
    zkShift,                                      //
    (PTR(Fp, io),                                 //
     SIZE(polyCount),                             //
     CALC(bits, log2Ceil(io.size() / polyCount)), //
     CALC(count, io.size()),                      //
     REQ(io.size() == polyCount * (1 << bits))),
    {
      uint32_t pos = idx & ((1 << bits) - 1);
      uint32_t posRev = accel_rev32(pos) >> (32 - bits);
      Fp pow3 = pow(Fp(3), posRev);
      io[idx] = io[idx] * pow3;
    })