Host.h revision 327952 
1//===- llvm/Support/Host.h - Host machine characteristics --------*- 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// Methods for querying the nature of the host machine.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_HOST_H
15#define LLVM_SUPPORT_HOST_H
16
17#include "llvm/ADT/StringMap.h"
18
19#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__)
20#include <endian.h>
21#elif defined(_AIX)
22#include <sys/machine.h>
23#elif defined(__sun)
24/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
25#include <sys/types.h>
26#define BIG_ENDIAN 4321
27#define LITTLE_ENDIAN 1234
28#if defined(_BIG_ENDIAN)
29#define BYTE_ORDER BIG_ENDIAN
30#else
31#define BYTE_ORDER LITTLE_ENDIAN
32#endif
33#else
34#if !defined(BYTE_ORDER) && !defined(LLVM_ON_WIN32)
35#include <machine/endian.h>
36#endif
37#endif
38
39#include <string>
40
41namespace llvm {
42namespace sys {
43
44#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
45constexpr bool IsBigEndianHost = true;
46#else
47constexpr bool IsBigEndianHost = false;
48#endif
49
50  static const bool IsLittleEndianHost = !IsBigEndianHost;
51
52  /// getDefaultTargetTriple() - Return the default target triple the compiler
53  /// has been configured to produce code for.
54  ///
55  /// The target triple is a string in the format of:
56  ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
57  /// or
58  ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
59  std::string getDefaultTargetTriple();
60
61  /// getProcessTriple() - Return an appropriate target triple for generating
62  /// code to be loaded into the current process, e.g. when using the JIT.
63  std::string getProcessTriple();
64
65  /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
66  /// of the name is target dependent, and suitable for passing as -mcpu to the
67  /// target which matches the host.
68  ///
69  /// \return - The host CPU name, or empty if the CPU could not be determined.
70  StringRef getHostCPUName();
71
72  /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
73  /// The particular format of the names are target dependent, and suitable for
74  /// passing as -mattr to the target which matches the host.
75  ///
76  /// \param Features - A string mapping feature names to either
77  /// true (if enabled) or false (if disabled). This routine makes no guarantees
78  /// about exactly which features may appear in this map, except that they are
79  /// all valid LLVM feature names.
80  ///
81  /// \return - True on success.
82  bool getHostCPUFeatures(StringMap<bool> &Features);
83
84  /// Get the number of physical cores (as opposed to logical cores returned
85  /// from thread::hardware_concurrency(), which includes hyperthreads).
86  /// Returns -1 if unknown for the current host system.
87  int getHostNumPhysicalCores();
88
89  namespace detail {
90  /// Helper functions to extract HostCPUName from /proc/cpuinfo on linux.
91  StringRef getHostCPUNameForPowerPC(const StringRef &ProcCpuinfoContent);
92  StringRef getHostCPUNameForARM(const StringRef &ProcCpuinfoContent);
93  StringRef getHostCPUNameForS390x(const StringRef &ProcCpuinfoContent);
94  StringRef getHostCPUNameForBPF();
95  }
96}
97}
98
99#endif
100