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 #else
24 #if !defined(BYTE_ORDER) && !defined(LLVM_ON_WIN32)
25 #include <machine/endian.h>
26 #endif
27 #endif
28 
29 #include <string>
30 
31 namespace llvm {
32 namespace sys {
33 
34 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
35   static const bool IsBigEndianHost = true;
36 #else
37   static const bool IsBigEndianHost = false;
38 #endif
39 
40   static const bool IsLittleEndianHost = !IsBigEndianHost;
41 
42   /// getDefaultTargetTriple() - Return the default target triple the compiler
43   /// has been configured to produce code for.
44   ///
45   /// The target triple is a string in the format of:
46   ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
47   /// or
48   ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
49   std::string getDefaultTargetTriple();
50 
51   /// getProcessTriple() - Return an appropriate target triple for generating
52   /// code to be loaded into the current process, e.g. when using the JIT.
53   std::string getProcessTriple();
54 
55   /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
56   /// of the name is target dependent, and suitable for passing as -mcpu to the
57   /// target which matches the host.
58   ///
59   /// \return - The host CPU name, or empty if the CPU could not be determined.
60   StringRef getHostCPUName();
61 
62   /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
63   /// The particular format of the names are target dependent, and suitable for
64   /// passing as -mattr to the target which matches the host.
65   ///
66   /// \param Features - A string mapping feature names to either
67   /// true (if enabled) or false (if disabled). This routine makes no guarantees
68   /// about exactly which features may appear in this map, except that they are
69   /// all valid LLVM feature names.
70   ///
71   /// \return - True on success.
72   bool getHostCPUFeatures(StringMap<bool> &Features);
73 
74   /// Get the number of physical cores (as opposed to logical cores returned
75   /// from thread::hardware_concurrency(), which includes hyperthreads).
76   /// Returns -1 if unknown for the current host system.
77   int getHostNumPhysicalCores();
78 }
79 }
80 
81 #endif
82