1 //===- llvm/Support/Host.h - Host machine characteristics --------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Methods for querying the nature of the host machine.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_SUPPORT_HOST_H
14 #define LLVM_SUPPORT_HOST_H
15 
16 #include "llvm/ADT/StringMap.h"
17 
18 #include <string>
19 
20 namespace llvm {
21 namespace sys {
22 
23   /// getDefaultTargetTriple() - Return the default target triple the compiler
24   /// has been configured to produce code for.
25   ///
26   /// The target triple is a string in the format of:
27   ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
28   /// or
29   ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
30   std::string getDefaultTargetTriple();
31 
32   /// getProcessTriple() - Return an appropriate target triple for generating
33   /// code to be loaded into the current process, e.g. when using the JIT.
34   std::string getProcessTriple();
35 
36   /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
37   /// of the name is target dependent, and suitable for passing as -mcpu to the
38   /// target which matches the host.
39   ///
40   /// \return - The host CPU name, or empty if the CPU could not be determined.
41   StringRef getHostCPUName();
42 
43   /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
44   /// The particular format of the names are target dependent, and suitable for
45   /// passing as -mattr to the target which matches the host.
46   ///
47   /// \param Features - A string mapping feature names to either
48   /// true (if enabled) or false (if disabled). This routine makes no guarantees
49   /// about exactly which features may appear in this map, except that they are
50   /// all valid LLVM feature names.
51   ///
52   /// \return - True on success.
53   bool getHostCPUFeatures(StringMap<bool> &Features);
54 
55   /// Get the number of physical cores (as opposed to logical cores returned
56   /// from thread::hardware_concurrency(), which includes hyperthreads).
57   /// Returns -1 if unknown for the current host system.
58   int getHostNumPhysicalCores();
59 
60   namespace detail {
61   /// Helper functions to extract HostCPUName from /proc/cpuinfo on linux.
62   StringRef getHostCPUNameForPowerPC(StringRef ProcCpuinfoContent);
63   StringRef getHostCPUNameForARM(StringRef ProcCpuinfoContent);
64   StringRef getHostCPUNameForS390x(StringRef ProcCpuinfoContent);
65   StringRef getHostCPUNameForBPF();
66   }
67 }
68 }
69 
70 #endif
71