Host.h revision 321369 
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#include "llvm/Support/MemoryBuffer.h"
19
20#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__)
21#include <endian.h>
22#elif defined(_AIX)
23#include <sys/machine.h>
24#elif defined(__sun)
25/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
26#include <sys/types.h>
27#define BIG_ENDIAN 4321
28#define LITTLE_ENDIAN 1234
29#if defined(_BIG_ENDIAN)
30#define BYTE_ORDER BIG_ENDIAN
31#else
32#define BYTE_ORDER LITTLE_ENDIAN
33#endif
34#else
35#if !defined(BYTE_ORDER) && !defined(LLVM_ON_WIN32)
36#include <machine/endian.h>
37#endif
38#endif
39
40#include <string>
41
42namespace llvm {
43namespace sys {
44
45#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
46constexpr bool IsBigEndianHost = true;
47#else
48constexpr bool IsBigEndianHost = false;
49#endif
50
51  static const bool IsLittleEndianHost = !IsBigEndianHost;
52
53  /// getDefaultTargetTriple() - Return the default target triple the compiler
54  /// has been configured to produce code for.
55  ///
56  /// The target triple is a string in the format of:
57  ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
58  /// or
59  ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
60  std::string getDefaultTargetTriple();
61
62  /// getProcessTriple() - Return an appropriate target triple for generating
63  /// code to be loaded into the current process, e.g. when using the JIT.
64  std::string getProcessTriple();
65
66  /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
67  /// of the name is target dependent, and suitable for passing as -mcpu to the
68  /// target which matches the host.
69  ///
70  /// \return - The host CPU name, or empty if the CPU could not be determined.
71  StringRef getHostCPUName();
72
73  /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
74  /// The particular format of the names are target dependent, and suitable for
75  /// passing as -mattr to the target which matches the host.
76  ///
77  /// \param Features - A string mapping feature names to either
78  /// true (if enabled) or false (if disabled). This routine makes no guarantees
79  /// about exactly which features may appear in this map, except that they are
80  /// all valid LLVM feature names.
81  ///
82  /// \return - True on success.
83  bool getHostCPUFeatures(StringMap<bool> &Features);
84
85  /// Get the number of physical cores (as opposed to logical cores returned
86  /// from thread::hardware_concurrency(), which includes hyperthreads).
87  /// Returns -1 if unknown for the current host system.
88  int getHostNumPhysicalCores();
89
90  namespace detail {
91  /// Helper functions to extract HostCPUName from /proc/cpuinfo on linux.
92  StringRef getHostCPUNameForPowerPC(const StringRef &ProcCpuinfoContent);
93  StringRef getHostCPUNameForARM(const StringRef &ProcCpuinfoContent);
94  StringRef getHostCPUNameForS390x(const StringRef &ProcCpuinfoContent);
95  }
96}
97}
98
99#endif
100