1 //===-- llvm/Support/DJB.h ---DJB Hash --------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains support for the DJ Bernstein hash function. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_SUPPORT_DJB_H 14 #define LLVM_SUPPORT_DJB_H 15 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/Support/Compiler.h" 18 19 namespace llvm { 20 21 /// The Bernstein hash function used by the DWARF accelerator tables. 22 inline uint32_t djbHash(StringRef Buffer, uint32_t H = 5381) { 23 for (unsigned char C : Buffer.bytes()) 24 H = (H << 5) + H + C; 25 return H; 26 } 27 28 /// Computes the Bernstein hash after folding the input according to the Dwarf 5 29 /// standard case folding rules. 30 LLVM_ABI uint32_t caseFoldingDjbHash(StringRef Buffer, uint32_t H = 5381); 31 } // namespace llvm 32 33 #endif // LLVM_SUPPORT_DJB_H 34