Tweak code into an equivalent form for which icc

doesn't warn about unreachable instructions.  Patch
by Erick Tryzelaar (#111).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81110 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/System/Mutex.h

@@ -93,32 +93,36 @@ namespace llvm
         MutexImpl(rec), acquired(0), recursive(rec) { }
       
       bool acquire() {
-        if (!mt_only || llvm_is_multithreaded())
+        if (!mt_only || llvm_is_multithreaded()) {
           return MutexImpl::acquire();
-        
+        } else {
-        // Single-threaded debugging code.  This would be racy in multithreaded
+          // Single-threaded debugging code.  This would be racy in
-        // mode, but provides not sanity checks in single threaded mode.
+          // multithreaded mode, but provides not sanity checks in single
+          // threaded mode.
           assert((recursive || acquired == 0) && "Lock already acquired!!");
           ++acquired;
           return true;
         }
+      }
 
       bool release() {
-        if (!mt_only || llvm_is_multithreaded())
+        if (!mt_only || llvm_is_multithreaded()) {
           return MutexImpl::release();
-        
+        } else {
-        // Single-threaded debugging code.  This would be racy in multithreaded
+          // Single-threaded debugging code.  This would be racy in
-        // mode, but provides not sanity checks in single threaded mode.
+          // multithreaded mode, but provides not sanity checks in single
+          // threaded mode.
           assert(((recursive && acquired) || (acquired == 1)) &&
                  "Lock not acquired before release!");
           --acquired;
           return true;
         }
+      }
 
       bool tryacquire() {
         if (!mt_only || llvm_is_multithreaded())
           return MutexImpl::tryacquire();
-        return true;
+        else return true;
       }
       
       private:

lib/System/Mutex.cpp

@@ -115,8 +115,7 @@ MutexImpl::acquire()
 
     int errorcode = pthread_mutex_lock(mutex);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 bool
@@ -129,8 +128,7 @@ MutexImpl::release()
 
     int errorcode = pthread_mutex_unlock(mutex);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 bool
@@ -143,8 +141,7 @@ MutexImpl::tryacquire()
 
     int errorcode = pthread_mutex_trylock(mutex);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 }

lib/System/RWMutex.cpp

@@ -117,8 +117,7 @@ RWMutexImpl::reader_acquire()
 
     int errorcode = pthread_rwlock_rdlock(rwlock);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 bool
@@ -131,8 +130,7 @@ RWMutexImpl::reader_release()
 
     int errorcode = pthread_rwlock_unlock(rwlock);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 bool
@@ -145,8 +143,7 @@ RWMutexImpl::writer_acquire()
 
     int errorcode = pthread_rwlock_wrlock(rwlock);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 bool
@@ -159,8 +156,7 @@ RWMutexImpl::writer_release()
 
     int errorcode = pthread_rwlock_unlock(rwlock);
     return errorcode == 0;
-  }
+  } else return false;
-  return false;
 }
 
 }

lib/System/Unix/Process.inc

@@ -181,25 +181,28 @@ void Process::PreventCoreFiles() {
 bool Process::StandardInIsUserInput() {
 #if HAVE_ISATTY
   return isatty(0);
-#endif
+#else
   // If we don't have isatty, just return false.
   return false;
+#endif
 }
 
 bool Process::StandardOutIsDisplayed() {
 #if HAVE_ISATTY
   return isatty(1);
-#endif
+#else
   // If we don't have isatty, just return false.
   return false;
+#endif
 }
 
 bool Process::StandardErrIsDisplayed() {
 #if HAVE_ISATTY
   return isatty(2);
-#endif
+#else
   // If we don't have isatty, just return false.
   return false;
+#endif
 }
 
 static unsigned getColumns(int FileID) {