forked from OSchip/llvm-project
24 lines
886 B
C++
24 lines
886 B
C++
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//===-- runtime/buffer.cpp --------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "buffer.h"
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#include <algorithm>
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namespace Fortran::runtime::io {
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// Here's a very old trick for shifting circular buffer data cheaply
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// without a need for a temporary array.
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void LeftShiftBufferCircularly(
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char *buffer, std::size_t bytes, std::size_t shift) {
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// Assume that we start with "efgabcd" and the left shift is 3.
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std::reverse(buffer, buffer + shift); // "gfeabcd"
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std::reverse(buffer, buffer + bytes); // "dcbaefg"
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std::reverse(buffer, buffer + bytes - shift); // "abcdefg"
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}
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}
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