1 //===- FuzzerBuiltinsMSVC.h - Internal header for builtins ------*- C++ -* ===//
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
7 //===----------------------------------------------------------------------===//
8 // Wrapper functions and marcos that use intrinsics instead of builtin functions
9 // which cannot be compiled by MSVC.
10 //===----------------------------------------------------------------------===//
12 #ifndef LLVM_FUZZER_BUILTINS_MSVC_H
13 #define LLVM_FUZZER_BUILTINS_MSVC_H
15 #include "FuzzerPlatform.h"
22 // __builtin_return_address() cannot be compiled with MSVC. Use the equivalent
24 #define GET_CALLER_PC() _ReturnAddress()
28 inline uint8_t Bswap(uint8_t x) { return x; }
29 // Use alternatives to __builtin functions from <stdlib.h> and <intrin.h> on
30 // Windows since the builtins are not supported by MSVC.
31 inline uint16_t Bswap(uint16_t x) { return _byteswap_ushort(x); }
32 inline uint32_t Bswap(uint32_t x) { return _byteswap_ulong(x); }
33 inline uint64_t Bswap(uint64_t x) { return _byteswap_uint64(x); }
35 // The functions below were mostly copied from
36 // compiler-rt/lib/builtins/int_lib.h which defines the __builtin functions used
37 // outside of Windows.
38 inline uint32_t Clzll(uint64_t X) {
39 unsigned long LeadZeroIdx = 0;
41 #if !defined(_M_ARM) && !defined(_M_X64)
42 // Scan the high 32 bits.
43 if (_BitScanReverse(&LeadZeroIdx, static_cast<unsigned long>(X >> 32)))
44 return static_cast<int>(63 - (LeadZeroIdx + 32)); // Create a bit offset from the MSB.
45 // Scan the low 32 bits.
46 if (_BitScanReverse(&LeadZeroIdx, static_cast<unsigned long>(X)))
47 return static_cast<int>(63 - LeadZeroIdx);
50 if (_BitScanReverse64(&LeadZeroIdx, X)) return 63 - LeadZeroIdx;
55 inline uint32_t Clz(uint32_t X) {
56 unsigned long LeadZeroIdx = 0;
57 if (_BitScanReverse(&LeadZeroIdx, X)) return 31 - LeadZeroIdx;
61 inline int Popcountll(unsigned long long X) {
62 #if !defined(_M_ARM) && !defined(_M_X64)
63 return __popcnt(X) + __popcnt(X >> 32);
71 #endif // LIBFUZER_MSVC
72 #endif // LLVM_FUZZER_BUILTINS_MSVC_H