diff --git a/lib/Support/Mutex.cpp b/lib/Support/Mutex.cpp
index 6a873cb0004..e146b8b0ed1 100644
--- a/lib/Support/Mutex.cpp
+++ b/lib/Support/Mutex.cpp
@@ -40,109 +40,80 @@ bool MutexImpl::tryacquire() { return true; }
 namespace llvm {
 using namespace sys;
 
-
-// This variable is useful for situations where the pthread library has been
-// compiled with weak linkage for its interface symbols. This allows the
-// threading support to be turned off by simply not linking against -lpthread.
-// In that situation, the value of pthread_mutex_init will be 0 and
-// consequently pthread_enabled will be false. In such situations, all the
-// pthread operations become no-ops and the functions all return false. If
-// pthread_mutex_init does have an address, then mutex support is enabled.
-// Note: all LLVM tools will link against -lpthread if its available since it
-//       is configured into the LIBS variable.
-// Note: this line of code generates a warning if pthread_mutex_init is not
-//       declared with weak linkage. It's safe to ignore the warning.
-static const bool pthread_enabled = true;
-
 // Construct a Mutex using pthread calls
 MutexImpl::MutexImpl( bool recursive)
   : data_(0)
 {
-  if (pthread_enabled)
-  {
-    // Declare the pthread_mutex data structures
-    pthread_mutex_t* mutex =
-      static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
-    pthread_mutexattr_t attr;
+  // Declare the pthread_mutex data structures
+  pthread_mutex_t* mutex =
+    static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
+  pthread_mutexattr_t attr;
 
-    // Initialize the mutex attributes
-    int errorcode = pthread_mutexattr_init(&attr);
-    assert(errorcode == 0);
+  // Initialize the mutex attributes
+  int errorcode = pthread_mutexattr_init(&attr);
+  assert(errorcode == 0);
 
-    // Initialize the mutex as a recursive mutex, if requested, or normal
-    // otherwise.
-    int kind = ( recursive  ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
-    errorcode = pthread_mutexattr_settype(&attr, kind);
-    assert(errorcode == 0);
+  // Initialize the mutex as a recursive mutex, if requested, or normal
+  // otherwise.
+  int kind = ( recursive  ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
+  errorcode = pthread_mutexattr_settype(&attr, kind);
+  assert(errorcode == 0);
 
 #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
-    // Make it a process local mutex
-    errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
-    assert(errorcode == 0);
+  // Make it a process local mutex
+  errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
+  assert(errorcode == 0);
 #endif
 
-    // Initialize the mutex
-    errorcode = pthread_mutex_init(mutex, &attr);
-    assert(errorcode == 0);
+  // Initialize the mutex
+  errorcode = pthread_mutex_init(mutex, &attr);
+  assert(errorcode == 0);
 
-    // Destroy the attributes
-    errorcode = pthread_mutexattr_destroy(&attr);
-    assert(errorcode == 0);
+  // Destroy the attributes
+  errorcode = pthread_mutexattr_destroy(&attr);
+  assert(errorcode == 0);
 
-    // Assign the data member
-    data_ = mutex;
-  }
+  // Assign the data member
+  data_ = mutex;
 }
 
 // Destruct a Mutex
 MutexImpl::~MutexImpl()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
-    pthread_mutex_destroy(mutex);
-    free(mutex);
-  }
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != 0);
+  pthread_mutex_destroy(mutex);
+  free(mutex);
 }
 
 bool
 MutexImpl::acquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != 0);
 
-    int errorcode = pthread_mutex_lock(mutex);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_mutex_lock(mutex);
+  return errorcode == 0;
 }
 
 bool
 MutexImpl::release()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != 0);
 
-    int errorcode = pthread_mutex_unlock(mutex);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_mutex_unlock(mutex);
+  return errorcode == 0;
 }
 
 bool
 MutexImpl::tryacquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != 0);
 
-    int errorcode = pthread_mutex_trylock(mutex);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_mutex_trylock(mutex);
+  return errorcode == 0;
 }
 
 }
diff --git a/lib/Support/RWMutex.cpp b/lib/Support/RWMutex.cpp
index d14b9765b85..6a34f2d0852 100644
--- a/lib/Support/RWMutex.cpp
+++ b/lib/Support/RWMutex.cpp
@@ -42,107 +42,75 @@ bool RWMutexImpl::writer_release() { return true; }
 namespace llvm {
 using namespace sys;
 
-
-// This variable is useful for situations where the pthread library has been
-// compiled with weak linkage for its interface symbols. This allows the
-// threading support to be turned off by simply not linking against -lpthread.
-// In that situation, the value of pthread_mutex_init will be 0 and
-// consequently pthread_enabled will be false. In such situations, all the
-// pthread operations become no-ops and the functions all return false. If
-// pthread_rwlock_init does have an address, then rwlock support is enabled.
-// Note: all LLVM tools will link against -lpthread if its available since it
-//       is configured into the LIBS variable.
-// Note: this line of code generates a warning if pthread_rwlock_init is not
-//       declared with weak linkage. It's safe to ignore the warning.
-static const bool pthread_enabled = true;
-
 // Construct a RWMutex using pthread calls
 RWMutexImpl::RWMutexImpl()
   : data_(0)
 {
-  if (pthread_enabled)
-  {
-    // Declare the pthread_rwlock data structures
-    pthread_rwlock_t* rwlock =
-      static_cast<pthread_rwlock_t*>(malloc(sizeof(pthread_rwlock_t)));
+  // Declare the pthread_rwlock data structures
+  pthread_rwlock_t* rwlock =
+    static_cast<pthread_rwlock_t*>(malloc(sizeof(pthread_rwlock_t)));
 
 #ifdef __APPLE__
-    // Workaround a bug/mis-feature in Darwin's pthread_rwlock_init.
-    bzero(rwlock, sizeof(pthread_rwlock_t));
+  // Workaround a bug/mis-feature in Darwin's pthread_rwlock_init.
+  bzero(rwlock, sizeof(pthread_rwlock_t));
 #endif
 
-    // Initialize the rwlock
-    int errorcode = pthread_rwlock_init(rwlock, NULL);
-    (void)errorcode;
-    assert(errorcode == 0);
+  // Initialize the rwlock
+  int errorcode = pthread_rwlock_init(rwlock, NULL);
+  (void)errorcode;
+  assert(errorcode == 0);
 
-    // Assign the data member
-    data_ = rwlock;
-  }
+  // Assign the data member
+  data_ = rwlock;
 }
 
 // Destruct a RWMutex
 RWMutexImpl::~RWMutexImpl()
 {
-  if (pthread_enabled)
-  {
-    pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-    assert(rwlock != 0);
-    pthread_rwlock_destroy(rwlock);
-    free(rwlock);
-  }
+  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+  assert(rwlock != 0);
+  pthread_rwlock_destroy(rwlock);
+  free(rwlock);
 }
 
 bool
 RWMutexImpl::reader_acquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-    assert(rwlock != 0);
+  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+  assert(rwlock != 0);
 
-    int errorcode = pthread_rwlock_rdlock(rwlock);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_rwlock_rdlock(rwlock);
+  return errorcode == 0;
 }
 
 bool
 RWMutexImpl::reader_release()
 {
-  if (pthread_enabled)
-  {
-    pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-    assert(rwlock != 0);
+  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+  assert(rwlock != 0);
 
-    int errorcode = pthread_rwlock_unlock(rwlock);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_rwlock_unlock(rwlock);
+  return errorcode == 0;
 }
 
 bool
 RWMutexImpl::writer_acquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-    assert(rwlock != 0);
+  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+  assert(rwlock != 0);
 
-    int errorcode = pthread_rwlock_wrlock(rwlock);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_rwlock_wrlock(rwlock);
+  return errorcode == 0;
 }
 
 bool
 RWMutexImpl::writer_release()
 {
-  if (pthread_enabled)
-  {
-    pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
-    assert(rwlock != 0);
+  pthread_rwlock_t* rwlock = static_cast<pthread_rwlock_t*>(data_);
+  assert(rwlock != 0);
 
-    int errorcode = pthread_rwlock_unlock(rwlock);
-    return errorcode == 0;
-  } else return false;
+  int errorcode = pthread_rwlock_unlock(rwlock);
+  return errorcode == 0;
 }
 
 }