llvm/lib/Support/Hashing.cpp

   1 //===-------------- lib/Support/Hashing.cpp -------------------------------===//
   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 provides implementation bits for the LLVM common hashing
  10 // infrastructure. Documentation and most of the other information is in the
  11 // header file.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ADT/Hashing.h"
  16
  17 using namespace llvm;
  18
  19 // Provide a definition and static initializer for the fixed seed. This
  20 // initializer should always be zero to ensure its value can never appear to be
  21 // non-zero, even during dynamic initialization.
  22 uint64_t llvm::hashing::detail::fixed_seed_override = 0;
  23
  24 // Implement the function for forced setting of the fixed seed.
  25 // FIXME: Use atomic operations here so that there is no data race.
  26 void llvm::set_fixed_execution_hash_seed(uint64_t fixed_value) {
  27   hashing::detail::fixed_seed_override = fixed_value;
  28 }