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+//===-- llvm/Support/Threading.cpp- Control multithreading mode --*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines helper functions for running LLVM in a multi-threaded
+// environment.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Threading.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/Config/config.h"
+#include "llvm/Support/Host.h"
+
+#include <cassert>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+//=== WARNING: Implementation here must contain only TRULY operating system
+//=== independent code.
+//===----------------------------------------------------------------------===//
+
+bool llvm::llvm_is_multithreaded() {
+#if LLVM_ENABLE_THREADS != 0
+ return true;
+#else
+ return false;
+#endif
+}
+
+#if LLVM_ENABLE_THREADS == 0 || \
+ (!defined(_WIN32) && !defined(HAVE_PTHREAD_H))
+uint64_t llvm::get_threadid() { return 0; }
+
+uint32_t llvm::get_max_thread_name_length() { return 0; }
+
+void llvm::set_thread_name(const Twine &Name) {}
+
+void llvm::get_thread_name(SmallVectorImpl<char> &Name) { Name.clear(); }
+
+llvm::BitVector llvm::get_thread_affinity_mask() { return {}; }
+
+unsigned llvm::ThreadPoolStrategy::compute_thread_count() const {
+ // When threads are disabled, ensure clients will loop at least once.
+ return 1;
+}
+
+#else
+
+int computeHostNumHardwareThreads();
+
+unsigned llvm::ThreadPoolStrategy::compute_thread_count() const {
+ int MaxThreadCount = UseHyperThreads ? computeHostNumHardwareThreads()
+ : sys::getHostNumPhysicalCores();
+ if (MaxThreadCount <= 0)
+ MaxThreadCount = 1;
+ if (ThreadsRequested == 0)
+ return MaxThreadCount;
+ if (!Limit)
+ return ThreadsRequested;
+ return std::min((unsigned)MaxThreadCount, ThreadsRequested);
+}
+
+// Include the platform-specific parts of this class.
+#ifdef LLVM_ON_UNIX
+#include "Unix/Threading.inc"
+#endif
+#ifdef _WIN32
+#include "Windows/Threading.inc"
+#endif
+
+// Must be included after Threading.inc to provide definition for llvm::thread
+// because FreeBSD's condvar.h (included by user.h) misuses the "thread"
+// keyword.
+#include "llvm/Support/thread.h"
+
+#if defined(__APPLE__)
+ // Darwin's default stack size for threads except the main one is only 512KB,
+ // which is not enough for some/many normal LLVM compilations. This implements
+ // the same interface as std::thread but requests the same stack size as the
+ // main thread (8MB) before creation.
+const llvm::Optional<unsigned> llvm::thread::DefaultStackSize = 8 * 1024 * 1024;
+#else
+const llvm::Optional<unsigned> llvm::thread::DefaultStackSize = None;
+#endif
+
+
+#endif
+
+Optional<ThreadPoolStrategy>
+llvm::get_threadpool_strategy(StringRef Num, ThreadPoolStrategy Default) {
+ if (Num == "all")
+ return llvm::hardware_concurrency();
+ if (Num.empty())
+ return Default;
+ unsigned V;
+ if (Num.getAsInteger(10, V))
+ return None; // malformed 'Num' value
+ if (V == 0)
+ return Default;
+
+ // Do not take the Default into account. This effectively disables
+ // heavyweight_hardware_concurrency() if the user asks for any number of
+ // threads on the cmd-line.
+ ThreadPoolStrategy S = llvm::hardware_concurrency();
+ S.ThreadsRequested = V;
+ return S;
+}