SPDX-License-Identifier: MIT

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================================================================================

The opt/fft_neon.c is derived from the implementation 
(https://github.com/GMUCERG/Falcon_NEON) that belongs to the paper 
"Fast Falcon Signature Generation and Verification Using ARMv8 NEON Instructions" 
by Duc Tri Nguyen and Prof. Kris Gaj at CERG GMU, accepted to AfricaCrypt 2023.

   Copyright 2023 Duc Tri Nguyen and Prof. Kris Gaj at CERG GMU

   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.