include/llvm/Support/Host.h

   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 #if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__)
  19 #include <endian.h>
  20 #elif defined(_AIX)
  21 #include <sys/machine.h>
  22 #elif defined(__sun)
  23 /* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
  24 #include <sys/types.h>
  25 #define BIG_ENDIAN 4321
  26 #define LITTLE_ENDIAN 1234
  27 #if defined(_BIG_ENDIAN)
  28 #define BYTE_ORDER BIG_ENDIAN
  29 #else
  30 #define BYTE_ORDER LITTLE_ENDIAN
  31 #endif
  32 #else
  33 #if !defined(BYTE_ORDER) && !defined(_WIN32)
  34 #include <machine/endian.h>
  35 #endif
  36 #endif
  37
  38 #include <string>
  39
  40 namespace llvm {
  41 namespace sys {
  42
  43 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
  44 constexpr bool IsBigEndianHost = true;
  45 #else
  46 constexpr bool IsBigEndianHost = false;
  47 #endif
  48
  49   static const bool IsLittleEndianHost = !IsBigEndianHost;
  50
  51   /// getDefaultTargetTriple() - Return the default target triple the compiler
  52   /// has been configured to produce code for.
  53   ///
  54   /// The target triple is a string in the format of:
  55   ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
  56   /// or
  57   ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
  58   std::string getDefaultTargetTriple();
  59
  60   /// getProcessTriple() - Return an appropriate target triple for generating
  61   /// code to be loaded into the current process, e.g. when using the JIT.
  62   std::string getProcessTriple();
  63
  64   /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
  65   /// of the name is target dependent, and suitable for passing as -mcpu to the
  66   /// target which matches the host.
  67   ///
  68   /// \return - The host CPU name, or empty if the CPU could not be determined.
  69   StringRef getHostCPUName();
  70
  71   /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
  72   /// The particular format of the names are target dependent, and suitable for
  73   /// passing as -mattr to the target which matches the host.
  74   ///
  75   /// \param Features - A string mapping feature names to either
  76   /// true (if enabled) or false (if disabled). This routine makes no guarantees
  77   /// about exactly which features may appear in this map, except that they are
  78   /// all valid LLVM feature names.
  79   ///
  80   /// \return - True on success.
  81   bool getHostCPUFeatures(StringMap<bool> &Features);
  82
  83   /// Get the number of physical cores (as opposed to logical cores returned
  84   /// from thread::hardware_concurrency(), which includes hyperthreads).
  85   /// Returns -1 if unknown for the current host system.
  86   int getHostNumPhysicalCores();
  87
  88   namespace detail {
  89   /// Helper functions to extract HostCPUName from /proc/cpuinfo on linux.
  90   StringRef getHostCPUNameForPowerPC(StringRef ProcCpuinfoContent);
  91   StringRef getHostCPUNameForARM(StringRef ProcCpuinfoContent);
  92   StringRef getHostCPUNameForS390x(StringRef ProcCpuinfoContent);
  93   StringRef getHostCPUNameForBPF();
  94   }
  95 }
  96 }
  97
  98 #endif