forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			97 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This file defines helper functions for running LLVM in a multi-threaded
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| // environment.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "llvm/Support/Threading.h"
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| #include "llvm/Config/config.h"
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| #include "llvm/Support/Host.h"
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| 
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| #include <cassert>
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| #include <errno.h>
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| #include <stdlib.h>
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| #include <string.h>
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| 
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| using namespace llvm;
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| 
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| //===----------------------------------------------------------------------===//
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| //=== WARNING: Implementation here must contain only TRULY operating system
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| //===          independent code.
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| //===----------------------------------------------------------------------===//
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| 
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| bool llvm::llvm_is_multithreaded() {
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| #if LLVM_ENABLE_THREADS != 0
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|   return true;
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| #else
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|   return false;
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| #endif
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| }
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| 
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| #if LLVM_ENABLE_THREADS == 0 ||                                                \
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|     (!defined(_WIN32) && !defined(HAVE_PTHREAD_H))
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| // Support for non-Win32, non-pthread implementation.
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| void llvm::llvm_execute_on_thread(void (*Fn)(void *), void *UserData,
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|                                   unsigned RequestedStackSize) {
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|   (void)RequestedStackSize;
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|   Fn(UserData);
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| }
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| 
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| unsigned llvm::heavyweight_hardware_concurrency() { return 1; }
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| 
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| unsigned llvm::hardware_concurrency() { return 1; }
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| 
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| uint64_t llvm::get_threadid() { return 0; }
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| 
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| uint32_t llvm::get_max_thread_name_length() { return 0; }
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| 
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| void llvm::set_thread_name(const Twine &Name) {}
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| 
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| void llvm::get_thread_name(SmallVectorImpl<char> &Name) { Name.clear(); }
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| 
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| #else
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| 
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| #include <thread>
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| unsigned llvm::heavyweight_hardware_concurrency() {
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|   // Since we can't get here unless LLVM_ENABLE_THREADS == 1, it is safe to use
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|   // `std::thread` directly instead of `llvm::thread` (and indeed, doing so
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|   // allows us to not define `thread` in the llvm namespace, which conflicts
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|   // with some platforms such as FreeBSD whose headers also define a struct
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|   // called `thread` in the global namespace which can cause ambiguity due to
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|   // ADL.
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|   int NumPhysical = sys::getHostNumPhysicalCores();
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|   if (NumPhysical == -1)
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|     return std::thread::hardware_concurrency();
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|   return NumPhysical;
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| }
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| 
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| unsigned llvm::hardware_concurrency() {
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| #if defined(HAVE_SCHED_GETAFFINITY) && defined(HAVE_CPU_COUNT)
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|   cpu_set_t Set;
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|   if (sched_getaffinity(0, sizeof(Set), &Set))
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|     return CPU_COUNT(&Set);
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| #endif
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|   // Guard against std::thread::hardware_concurrency() returning 0.
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|   if (unsigned Val = std::thread::hardware_concurrency())
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|     return Val;
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|   return 1;
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| }
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| 
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| // Include the platform-specific parts of this class.
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| #ifdef LLVM_ON_UNIX
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| #include "Unix/Threading.inc"
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| #endif
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| #ifdef _WIN32
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| #include "Windows/Threading.inc"
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| #endif
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| 
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| #endif
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