1 //===- FuzzerBuiltinsMSVC.h - Internal header for builtins ------*- 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 // Wrapper functions and marcos that use intrinsics instead of builtin functions 9 // which cannot be compiled by MSVC. 10 //===----------------------------------------------------------------------===// 11 12 #ifndef LLVM_FUZZER_BUILTINS_MSVC_H 13 #define LLVM_FUZZER_BUILTINS_MSVC_H 14 15 #include "FuzzerDefs.h" 16 17 #if LIBFUZZER_MSVC 18 #if !defined(_M_ARM) && !defined(_M_X64) 19 #error "_BitScanReverse64 unavailable on this platform so MSVC is unsupported." 20 #endif 21 #include <intrin.h> 22 #include <cstdint> 23 #include <cstdlib> 24 25 // __builtin_return_address() cannot be compiled with MSVC. Use the equivalent 26 // from <intrin.h> 27 #define GET_CALLER_PC() _ReturnAddress() 28 29 namespace fuzzer { 30 31 inline uint8_t Bswap(uint8_t x) { return x; } 32 // Use alternatives to __builtin functions from <stdlib.h> and <intrin.h> on 33 // Windows since the builtins are not supported by MSVC. 34 inline uint16_t Bswap(uint16_t x) { return _byteswap_ushort(x); } 35 inline uint32_t Bswap(uint32_t x) { return _byteswap_ulong(x); } 36 inline uint64_t Bswap(uint64_t x) { return _byteswap_uint64(x); } 37 38 // The functions below were mostly copied from 39 // compiler-rt/lib/builtins/int_lib.h which defines the __builtin functions used 40 // outside of Windows. 41 inline uint32_t Clzll(uint64_t X) { 42 unsigned long LeadZeroIdx = 0; 43 if (_BitScanReverse64(&LeadZeroIdx, X)) return 63 - LeadZeroIdx; 44 return 64; 45 } 46 47 inline uint32_t Clz(uint32_t X) { 48 unsigned long LeadZeroIdx = 0; 49 if (_BitScanReverse(&LeadZeroIdx, X)) return 31 - LeadZeroIdx; 50 return 32; 51 } 52 53 inline int Popcountll(unsigned long long X) { return __popcnt64(X); } 54 55 } // namespace fuzzer 56 57 #endif // LIBFUZER_MSVC 58 #endif // LLVM_FUZZER_BUILTINS_MSVC_H 59