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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 <string>
19 
20 namespace llvm {
21 namespace sys {
22 
isLittleEndianHost()23   inline bool isLittleEndianHost() {
24     union {
25       int i;
26       char c;
27     };
28     i = 1;
29     return c;
30   }
31 
isBigEndianHost()32   inline bool isBigEndianHost() {
33     return !isLittleEndianHost();
34   }
35 
36   /// getDefaultTargetTriple() - Return the default target triple the compiler
37   /// has been configured to produce code for.
38   ///
39   /// The target triple is a string in the format of:
40   ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
41   /// or
42   ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
43   std::string getDefaultTargetTriple();
44 
45   /// getProcessTriple() - Return an appropriate target triple for generating
46   /// code to be loaded into the current process, e.g. when using the JIT.
47   std::string getProcessTriple();
48 
49   /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
50   /// of the name is target dependent, and suitable for passing as -mcpu to the
51   /// target which matches the host.
52   ///
53   /// \return - The host CPU name, or empty if the CPU could not be determined.
54   std::string getHostCPUName();
55 
56   /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
57   /// The particular format of the names are target dependent, and suitable for
58   /// passing as -mattr to the target which matches the host.
59   ///
60   /// \param Features - A string mapping feature names to either
61   /// true (if enabled) or false (if disabled). This routine makes no guarantees
62   /// about exactly which features may appear in this map, except that they are
63   /// all valid LLVM feature names.
64   ///
65   /// \return - True on success.
66   bool getHostCPUFeatures(StringMap<bool> &Features);
67 }
68 }
69 
70 #endif
71