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//===- FuzzerBuiltinsMSVC.h - Internal header for builtins ------*- C++ -* ===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Wrapper functions and marcos that use intrinsics instead of builtin functions
// which cannot be compiled by MSVC.
//===----------------------------------------------------------------------===//
#ifndef LLVM_FUZZER_BUILTINS_MSVC_H
#define LLVM_FUZZER_BUILTINS_MSVC_H
#include "FuzzerPlatform.h"
#if LIBFUZZER_MSVC
#include <intrin.h>
#include <cstdint>
#include <cstdlib>
// __builtin_return_address() cannot be compiled with MSVC. Use the equivalent
// from <intrin.h>
#define GET_CALLER_PC() _ReturnAddress()
namespace fuzzer {
inline uint8_t Bswap(uint8_t x) { return x; }
// Use alternatives to __builtin functions from <stdlib.h> and <intrin.h> on
// Windows since the builtins are not supported by MSVC.
inline uint16_t Bswap(uint16_t x) { return _byteswap_ushort(x); }
inline uint32_t Bswap(uint32_t x) { return _byteswap_ulong(x); }
inline uint64_t Bswap(uint64_t x) { return _byteswap_uint64(x); }
// The functions below were mostly copied from
// compiler-rt/lib/builtins/int_lib.h which defines the __builtin functions used
// outside of Windows.
inline uint32_t Clzll(uint64_t X) {
unsigned long LeadZeroIdx = 0;
#if !defined(_M_ARM) && !defined(_M_X64)
// Scan the high 32 bits.
if (_BitScanReverse(&LeadZeroIdx, static_cast<unsigned long>(X >> 32)))
return static_cast<int>(63 - (LeadZeroIdx + 32)); // Create a bit offset from the MSB.
// Scan the low 32 bits.
if (_BitScanReverse(&LeadZeroIdx, static_cast<unsigned long>(X)))
return static_cast<int>(63 - LeadZeroIdx);
#else
if (_BitScanReverse64(&LeadZeroIdx, X)) return 63 - LeadZeroIdx;
#endif
return 64;
}
inline uint32_t Clz(uint32_t X) {
unsigned long LeadZeroIdx = 0;
if (_BitScanReverse(&LeadZeroIdx, X)) return 31 - LeadZeroIdx;
return 32;
}
inline int Popcountll(unsigned long long X) {
#if !defined(_M_ARM) && !defined(_M_X64)
return __popcnt(X) + __popcnt(X >> 32);
#else
return __popcnt64(X);
#endif
}
} // namespace fuzzer
#endif // LIBFUZER_MSVC
#endif // LLVM_FUZZER_BUILTINS_MSVC_H