text: //===- llvm/Support/Host.h - Host machine characteristics --------*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // Methods for querying the nature of the host machine.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_SUPPORT_HOST_H
  #define LLVM_SUPPORT_HOST_H
  
  #include "llvm/ADT/StringMap.h"
  
  #include <string>
  
  namespace llvm {
  namespace sys {
  
    /// getDefaultTargetTriple() - Return the default target triple the compiler
    /// has been configured to produce code for.
    ///
    /// The target triple is a string in the format of:
    ///   CPU_TYPE-VENDOR-OPERATING_SYSTEM
    /// or
    ///   CPU_TYPE-VENDOR-KERNEL-OPERATING_SYSTEM
    std::string getDefaultTargetTriple();
  
    /// getProcessTriple() - Return an appropriate target triple for generating
    /// code to be loaded into the current process, e.g. when using the JIT.
    std::string getProcessTriple();
  
    /// getHostCPUName - Get the LLVM name for the host CPU. The particular format
    /// of the name is target dependent, and suitable for passing as -mcpu to the
    /// target which matches the host.
    ///
    /// \return - The host CPU name, or empty if the CPU could not be determined.
    StringRef getHostCPUName();
  
    /// getHostCPUFeatures - Get the LLVM names for the host CPU features.
    /// The particular format of the names are target dependent, and suitable for
    /// passing as -mattr to the target which matches the host.
    ///
    /// \param Features - A string mapping feature names to either
    /// true (if enabled) or false (if disabled). This routine makes no guarantees
    /// about exactly which features may appear in this map, except that they are
    /// all valid LLVM feature names.
    ///
    /// \return - True on success.
    bool getHostCPUFeatures(StringMap<bool> &Features);
  
    /// Get the number of physical cores (as opposed to logical cores returned
    /// from thread::hardware_concurrency(), which includes hyperthreads).
    /// Returns -1 if unknown for the current host system.
    int getHostNumPhysicalCores();
  
    namespace detail {
    /// Helper functions to extract HostCPUName from /proc/cpuinfo on linux.
    StringRef getHostCPUNameForPowerPC(StringRef ProcCpuinfoContent);
    StringRef getHostCPUNameForARM(StringRef ProcCpuinfoContent);
    StringRef getHostCPUNameForS390x(StringRef ProcCpuinfoContent);
    StringRef getHostCPUNameForBPF();
    }
  }
  }
  
  #endif
  