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1 //===-- llvm/Support/DJB.h ---DJB Hash --------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains support for the DJ Bernstein hash function.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_SUPPORT_DJB_H
15 #define LLVM_SUPPORT_DJB_H
16 
17 #include "llvm/ADT/StringRef.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 uint32_t caseFoldingDjbHash(StringRef Buffer, uint32_t H = 5381);
31 } // namespace llvm
32 
33 #endif // LLVM_SUPPORT_DJB_H
34