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diff --git a/clang-r353983/include/llvm/Support/JamCRC.h b/clang-r353983/include/llvm/Support/JamCRC.h
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+//===-- llvm/Support/JamCRC.h - Cyclic Redundancy Check ---------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an implementation of JamCRC.
+//
+// We will use the "Rocksoft^tm Model CRC Algorithm" to describe the properties
+// of this CRC:
+// Width : 32
+// Poly : 04C11DB7
+// Init : FFFFFFFF
+// RefIn : True
+// RefOut : True
+// XorOut : 00000000
+// Check : 340BC6D9 (result of CRC for "123456789")
+//
+// N.B. We permit flexibility of the "Init" value. Some consumers of this need
+// it to be zero.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_JAMCRC_H
+#define LLVM_SUPPORT_JAMCRC_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+template <typename T> class ArrayRef;
+
+class JamCRC {
+public:
+ JamCRC(uint32_t Init = 0xFFFFFFFFU) : CRC(Init) {}
+
+ // Update the CRC calculation with Data.
+ void update(ArrayRef<char> Data);
+
+ uint32_t getCRC() const { return CRC; }
+
+private:
+ uint32_t CRC;
+};
+} // End of namespace llvm
+
+#endif