Use Q_UNLIKELY for every qFatal()/qCritical()

If, after checking a condition, we issue a qFatal()
or a qCritical(), by definition that check is
unlikely to be true.

Tell the compiler so it can move the error handling
code out of the normal code path to increase the
effective icache size.

Moved conditional code around where possible so that
we could always use Q_UNLIKELY, instead of having to
revert to Q_LIKELY here and there.

In some cases, simplified the expressions newly wrapped
in Q_UNLIKELY as a drive-by.

Change-Id: I67537d62b04bc6977d69254690c5ebbdf98bfd6d
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

12 files changed, 55 insertions, 56 deletions

diff --git a/src/plugins/platforms/qnx/qqnxbuffer.cpp b/src/plugins/platforms/qnx/qqnxbuffer.cpp
index 2c3a42ac7c..8589775fdf 100644
--- a/src/plugins/platforms/qnx/qqnxbuffer.cpp
+++ b/src/plugins/platforms/qnx/qqnxbuffer.cpp
@@ -76,7 +76,7 @@ QQnxBuffer::QQnxBuffer(screen_buffer_t buffer)
             screen_get_buffer_property_pv(buffer, SCREEN_PROPERTY_POINTER, (void **)&dataPtr),
             "Failed to query buffer pointer");
 
-    if (dataPtr == 0)
+    if (Q_UNLIKELY(!dataPtr))
         qFatal("QQNX: buffer pointer is NULL, errno=%d", errno);
 
     // Get format of buffer
@@ -131,13 +131,13 @@ void QQnxBuffer::invalidateInCache()
     qBufferDebug() << Q_FUNC_INFO;
 
     // Verify native buffer exists
-    if (m_buffer == 0)
+    if (Q_UNLIKELY(!m_buffer))
         qFatal("QQNX: can't invalidate cache for null buffer");
 
     // Evict buffer's data from cache
     errno = 0;
     int result = msync(m_image.bits(), m_image.height() * m_image.bytesPerLine(), MS_INVALIDATE | MS_CACHE_ONLY);
-    if (result != 0)
+    if (Q_UNLIKELY(result != 0))
         qFatal("QQNX: failed to invalidate cache, errno=%d", errno);
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxeglwindow.cpp b/src/plugins/platforms/qnx/qqnxeglwindow.cpp
index 77630018e9..8faa474718 100644
--- a/src/plugins/platforms/qnx/qqnxeglwindow.cpp
+++ b/src/plugins/platforms/qnx/qqnxeglwindow.cpp
@@ -59,7 +59,7 @@ QQnxEglWindow::QQnxEglWindow(QWindow *window, screen_context_t context, bool nee
     // Set window usage
     const int val = SCREEN_USAGE_OPENGL_ES2;
     const int result = screen_set_window_property_iv(nativeHandle(), SCREEN_PROPERTY_USAGE, &val);
-    if (result != 0)
+    if (Q_UNLIKELY(result != 0))
         qFatal("QQnxEglWindow: failed to set window alpha usage, errno=%d", errno);
 
     m_requestedBufferSize = shouldMakeFullScreen() ? screen()->geometry().size() : window->geometry().size();
@@ -106,7 +106,7 @@ void QQnxEglWindow::destroyEGLSurface()
     // Destroy EGL surface if it exists
     if (m_eglSurface != EGL_NO_SURFACE) {
         EGLBoolean eglResult = eglDestroySurface(platformOpenGLContext()->getEglDisplay(), m_eglSurface);
-        if (eglResult != EGL_TRUE)
+        if (Q_UNLIKELY(eglResult != EGL_TRUE))
             qFatal("QQNX: failed to destroy EGL surface, err=%d", eglGetError());
     }
 
@@ -118,12 +118,12 @@ void QQnxEglWindow::swapEGLBuffers()
     qEglWindowDebug() << Q_FUNC_INFO;
     // Set current rendering API
     EGLBoolean eglResult = eglBindAPI(EGL_OPENGL_ES_API);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to set EGL API, err=%d", eglGetError());
 
     // Post EGL surface to window
     eglResult = eglSwapBuffers(m_platformOpenGLContext->getEglDisplay(), m_eglSurface);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to swap EGL buffers, err=%d", eglGetError());
 
     windowPosted();
@@ -178,15 +178,15 @@ int QQnxEglWindow::pixelFormat() const
     const QSurfaceFormat format = m_platformOpenGLContext->format();
     // Extract size of color channels from window format
     const int redSize = format.redBufferSize();
-    if (redSize == -1)
+    if (Q_UNLIKELY(redSize == -1))
         qFatal("QQnxWindow: red size not defined");
 
     const int greenSize = format.greenBufferSize();
-    if (greenSize == -1)
+    if (Q_UNLIKELY(greenSize == -1))
         qFatal("QQnxWindow: green size not defined");
 
     const int blueSize = format.blueBufferSize();
-    if (blueSize == -1)
+    if (Q_UNLIKELY(blueSize == -1))
         qFatal("QQnxWindow: blue size not defined");
 
     // select matching native format
diff --git a/src/plugins/platforms/qnx/qqnxglcontext.cpp b/src/plugins/platforms/qnx/qqnxglcontext.cpp
index deac419a36..266de22205 100644
--- a/src/plugins/platforms/qnx/qqnxglcontext.cpp
+++ b/src/plugins/platforms/qnx/qqnxglcontext.cpp
@@ -61,7 +61,7 @@ QQnxGLContext::QQnxGLContext(QOpenGLContext *glContext)
 
     // Set current rendering API
     EGLBoolean eglResult = eglBindAPI(EGL_OPENGL_ES_API);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to set EGL API, err=%d", eglGetError());
 
     // Get colour channel sizes from window format
@@ -113,7 +113,7 @@ QQnxGLContext::QQnxGLContext(QOpenGLContext *glContext)
 
     // Select EGL config based on requested window format
     m_eglConfig = q_configFromGLFormat(ms_eglDisplay, format);
-    if (m_eglConfig == 0)
+    if (Q_UNLIKELY(m_eglConfig == 0))
         qFatal("QQnxGLContext: failed to find EGL config");
 
     QQnxGLContext *glShareContext = static_cast<QQnxGLContext*>(m_glContext->shareHandle());
@@ -121,7 +121,7 @@ QQnxGLContext::QQnxGLContext(QOpenGLContext *glContext)
 
     m_eglContext = eglCreateContext(ms_eglDisplay, m_eglConfig, m_eglShareContext,
                                     contextAttrs(format));
-    if (m_eglContext == EGL_NO_CONTEXT) {
+    if (Q_UNLIKELY(m_eglContext == EGL_NO_CONTEXT)) {
         checkEGLError("eglCreateContext");
         qFatal("QQnxGLContext: failed to create EGL context, err=%d", eglGetError());
     }
@@ -170,13 +170,13 @@ void QQnxGLContext::initializeContext()
 
     // Initialize connection to EGL
     ms_eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-    if (ms_eglDisplay == EGL_NO_DISPLAY) {
+    if (Q_UNLIKELY(ms_eglDisplay == EGL_NO_DISPLAY)) {
         checkEGLError("eglGetDisplay");
         qFatal("QQnxGLContext: failed to obtain EGL display");
     }
 
     EGLBoolean eglResult = eglInitialize(ms_eglDisplay, 0, 0);
-    if (eglResult != EGL_TRUE) {
+    if (Q_UNLIKELY(eglResult != EGL_TRUE)) {
         checkEGLError("eglInitialize");
         qFatal("QQnxGLContext: failed to initialize EGL display, err=%d", eglGetError());
     }
@@ -198,7 +198,7 @@ bool QQnxGLContext::makeCurrent(QPlatformSurface *surface)
 
     // Set current rendering API
     EGLBoolean eglResult = eglBindAPI(EGL_OPENGL_ES_API);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQnxGLContext: failed to set EGL API, err=%d", eglGetError());
 
     QQnxEglWindow *platformWindow = dynamic_cast<QQnxEglWindow*>(surface);
@@ -227,12 +227,12 @@ void QQnxGLContext::doneCurrent()
 
     // set current rendering API
     EGLBoolean eglResult = eglBindAPI(EGL_OPENGL_ES_API);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to set EGL API, err=%d", eglGetError());
 
     // clear curent EGL context and unbind EGL surface
     eglResult = eglMakeCurrent(ms_eglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to clear current EGL context, err=%d", eglGetError());
 }
 
@@ -252,7 +252,7 @@ QFunctionPointer QQnxGLContext::getProcAddress(const QByteArray &procName)
 
     // Set current rendering API
     EGLBoolean eglResult = eglBindAPI(EGL_OPENGL_ES_API);
-    if (eglResult != EGL_TRUE)
+    if (Q_UNLIKELY(eglResult != EGL_TRUE))
         qFatal("QQNX: failed to set EGL API, err=%d", eglGetError());
 
     // Lookup EGL extension function pointer
diff --git a/src/plugins/platforms/qnx/qqnxglobal.cpp b/src/plugins/platforms/qnx/qqnxglobal.cpp
index 01e7675839..4d2599746e 100644
--- a/src/plugins/platforms/qnx/qqnxglobal.cpp
+++ b/src/plugins/platforms/qnx/qqnxglobal.cpp
@@ -44,8 +44,8 @@ void qScreenCheckError(int rc, const char *funcInfo, const char *message, bool c
         rc = screen_flush_context(QQnxIntegration::screenContext(), 0);
     }
 
-    if (rc) {
-        if (critical)
+    if (Q_UNLIKELY(rc)) {
+        if (Q_UNLIKELY(critical))
             qCritical("%s - Screen: %s - Error: %s (%i)", funcInfo, message, strerror(errno), errno);
         else
             qWarning("%s - Screen: %s - Error: %s (%i)", funcInfo, message, strerror(errno), errno);
diff --git a/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp b/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
index ed0db82685..603ddc5c2b 100644
--- a/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
+++ b/src/plugins/platforms/qnx/qqnxinputcontext_imf.cpp
@@ -530,29 +530,28 @@ static bool imfAvailable()
 
     if ( p_imf_client_init == 0 ) {
         void *handle = dlopen("libinput_client.so.1", 0);
-        if ( handle ) {
-            p_imf_client_init = (int32_t (*)()) dlsym(handle, "imf_client_init");
-            p_imf_client_disconnect = (void (*)()) dlsym(handle, "imf_client_disconnect");
-            p_ictrl_open_session = (const input_session_t *(*)(connection_interface_t *))dlsym(handle, "ictrl_open_session");
-            p_ictrl_close_session = (void (*)(input_session_t *))dlsym(handle, "ictrl_close_session");
-            p_ictrl_dispatch_event = (int32_t (*)(event_t *))dlsym(handle, "ictrl_dispatch_event");
-            p_vkb_init_selection_service = (int32_t (*)())dlsym(handle, "vkb_init_selection_service");
-            p_ictrl_get_num_active_sessions = (int32_t (*)())dlsym(handle, "ictrl_get_num_active_sessions");
-        } else {
+        if (Q_UNLIKELY(!handle)) {
             qCritical() << Q_FUNC_INFO << "libinput_client.so.1 is not present - IMF services are disabled.";
             s_imfDisabled = true;
             return false;
         }
-
-        if ( p_imf_client_init && p_ictrl_open_session && p_ictrl_dispatch_event ) {
-            s_imfReady = true;
-        } else {
+        p_imf_client_init = (int32_t (*)()) dlsym(handle, "imf_client_init");
+        p_imf_client_disconnect = (void (*)()) dlsym(handle, "imf_client_disconnect");
+        p_ictrl_open_session = (const input_session_t *(*)(connection_interface_t *))dlsym(handle, "ictrl_open_session");
+        p_ictrl_close_session = (void (*)(input_session_t *))dlsym(handle, "ictrl_close_session");
+        p_ictrl_dispatch_event = (int32_t (*)(event_t *))dlsym(handle, "ictrl_dispatch_event");
+        p_vkb_init_selection_service = (int32_t (*)())dlsym(handle, "vkb_init_selection_service");
+        p_ictrl_get_num_active_sessions = (int32_t (*)())dlsym(handle, "ictrl_get_num_active_sessions");
+
+        if (Q_UNLIKELY(!p_imf_client_init || !p_ictrl_open_session || !p_ictrl_dispatch_event)) {
             p_ictrl_open_session = 0;
             p_ictrl_dispatch_event = 0;
             s_imfDisabled = true;
             qCritical() << Q_FUNC_INFO << "libinput_client.so.1 did not contain the correct symbols, library mismatch? IMF services are disabled.";
             return false;
         }
+
+        s_imfReady = true;
     }
 
     return s_imfReady;
@@ -581,7 +580,7 @@ QQnxInputContext::QQnxInputContext(QQnxIntegration *integration, QQnxAbstractVir
     Q_ASSERT(sInputContextInstance == 0);
     sInputContextInstance = this;
 
-    if (p_imf_client_init() != 0) {
+    if (Q_UNLIKELY(p_imf_client_init() != 0)) {
         s_imfInitFailed = true;
         qCritical("imf_client_init failed - IMF services will be unavailable");
     }
diff --git a/src/plugins/platforms/qnx/qqnxintegration.cpp b/src/plugins/platforms/qnx/qqnxintegration.cpp
index 57f8213a4e..36d59ef134 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.cpp
+++ b/src/plugins/platforms/qnx/qqnxintegration.cpp
@@ -425,7 +425,7 @@ void QQnxIntegration::createDisplays()
                                                 &displayCount);
     Q_SCREEN_CRITICALERROR(result, "Failed to query display count");
 
-    if (displayCount < 1) {
+    if (Q_UNLIKELY(displayCount < 1)) {
         // Never happens, even if there's no display, libscreen returns 1
         qFatal("QQnxIntegration: displayCount=%d", displayCount);
     }
diff --git a/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp b/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
index aa47b5409b..d7221a9185 100644
--- a/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
+++ b/src/plugins/platforms/qnx/qqnxnavigatoreventnotifier.cpp
@@ -102,7 +102,7 @@ void QQnxNavigatorEventNotifier::parsePPS(const QByteArray &ppsData, QByteArray
     QList<QByteArray> lines = ppsData.split('\n');
 
     // validate pps object
-    if (lines.size() == 0 || lines.at(0) != "@control")
+    if (Q_UNLIKELY(lines.empty() || lines.at(0) != "@control"))
         qFatal("QQNX: unrecognized pps object, data=%s", ppsData.constData());
 
     // parse pps object attributes and extract values
@@ -160,7 +160,7 @@ void QQnxNavigatorEventNotifier::replyPPS(const QByteArray &res, const QByteArra
     // send pps message to navigator
     errno = 0;
     int bytes = write(m_fd, ppsData.constData(), ppsData.size());
-    if (bytes == -1)
+    if (Q_UNLIKELY(bytes == -1))
         qFatal("QQNX: failed to write navigator pps, errno=%d", errno);
 }
 
@@ -198,7 +198,7 @@ void QQnxNavigatorEventNotifier::readData()
     // attempt to read pps data
     errno = 0;
     int bytes = qt_safe_read(m_fd, buffer, ppsBufferSize - 1);
-    if (bytes == -1)
+    if (Q_UNLIKELY(bytes == -1))
         qFatal("QQNX: failed to read navigator pps, errno=%d", errno);
 
     // check if pps data was received
diff --git a/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp b/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
index c3b088ae5f..d5bdbb3ec6 100644
--- a/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
+++ b/src/plugins/platforms/qnx/qqnxnavigatorpps.cpp
@@ -100,7 +100,7 @@ bool QQnxNavigatorPps::sendPpsMessage(const QByteArray &message, const QByteArra
     // send pps message to navigator
     errno = 0;
     int bytes = qt_safe_write(m_fd, ppsMessage.constData(), ppsMessage.size());
-    if (bytes == -1)
+    if (Q_UNLIKELY(bytes == -1))
         qFatal("QQNX: failed to write navigator pps, errno=%d", errno);
 
     // allocate buffer for pps data
@@ -110,7 +110,7 @@ bool QQnxNavigatorPps::sendPpsMessage(const QByteArray &message, const QByteArra
     do {
         errno = 0;
         bytes = qt_safe_read(m_fd, buffer, ppsBufferSize - 1);
-        if (bytes == -1)
+        if (Q_UNLIKELY(bytes == -1))
             qFatal("QQNX: failed to read navigator pps, errno=%d", errno);
     } while (bytes == 0);
 
@@ -125,7 +125,7 @@ bool QQnxNavigatorPps::sendPpsMessage(const QByteArray &message, const QByteArra
     parsePPS(ppsData, responseFields);
 
     if (responseFields.contains("res") && responseFields.value("res") == message) {
-        if (responseFields.contains("err")) {
+        if (Q_UNLIKELY(responseFields.contains("err"))) {
             qCritical() << "navigator responded with error: " << responseFields.value("err");
             return false;
         }
@@ -142,7 +142,7 @@ void QQnxNavigatorPps::parsePPS(const QByteArray &ppsData, QHash<QByteArray, QBy
     QList<QByteArray> lines = ppsData.split('\n');
 
     // validate pps object
-    if (lines.size() == 0 || lines.at(0) != "@control")
+    if (Q_UNLIKELY(lines.empty() || lines.at(0) != "@control"))
         qFatal("QQNX: unrecognized pps object, data=%s", ppsData.constData());
 
     // parse pps object attributes and extract values
diff --git a/src/plugins/platforms/qnx/qqnxrasterwindow.cpp b/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
index 6a346e2bb4..30103b4b9a 100644
--- a/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
+++ b/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
@@ -61,7 +61,7 @@ QQnxRasterWindow::QQnxRasterWindow(QWindow *window, screen_context_t context, bo
 
     const int val = SCREEN_USAGE_NATIVE | SCREEN_USAGE_READ | SCREEN_USAGE_WRITE;
     const int result = screen_set_window_property_iv(nativeHandle(), SCREEN_PROPERTY_USAGE, &val);
-    if (result != 0)
+    if (Q_UNLIKELY(result != 0))
         qFatal("QQnxRasterWindow: failed to set window alpha usage, errno=%d", errno);
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
index 4baabbb4fa..01a54a8a5e 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
@@ -579,12 +579,12 @@ void QQnxScreenEventHandler::handlePropertyEvent(screen_event_t event)
 
     errno = 0;
     screen_window_t window = 0;
-    if (screen_get_event_property_pv(event, SCREEN_PROPERTY_WINDOW, (void**)&window) != 0)
+    if (Q_UNLIKELY(screen_get_event_property_pv(event, SCREEN_PROPERTY_WINDOW, (void**)&window) != 0))
         qFatal("QQnx: failed to query window property, errno=%d", errno);
 
     errno = 0;
     int property;
-    if (screen_get_event_property_iv(event, SCREEN_PROPERTY_NAME, &property) != 0)
+    if (Q_UNLIKELY(screen_get_event_property_iv(event, SCREEN_PROPERTY_NAME, &property) != 0))
         qFatal("QQnx: failed to query window property, errno=%d", errno);
 
     switch (property) {
@@ -601,7 +601,7 @@ void QQnxScreenEventHandler::handleKeyboardFocusPropertyEvent(screen_window_t wi
 {
     errno = 0;
     int focus = 0;
-    if (window && screen_get_window_property_iv(window, SCREEN_PROPERTY_KEYBOARD_FOCUS, &focus) != 0)
+    if (Q_UNLIKELY(window && screen_get_window_property_iv(window, SCREEN_PROPERTY_KEYBOARD_FOCUS, &focus) != 0))
         qFatal("QQnx: failed to query keyboard focus property, errno=%d", errno);
 
     QWindow *focusWindow = QQnxIntegration::window(window);
diff --git a/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp b/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
index 2c7a28e835..33e5cf2947 100644
--- a/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
+++ b/src/plugins/platforms/qnx/qqnxvirtualkeyboardpps.cpp
@@ -127,7 +127,7 @@ bool QQnxVirtualKeyboardPps::connect()
     }
 
     m_buffer = new char[ms_bufferSize];
-    if (!m_buffer) {
+    if (Q_UNLIKELY(!m_buffer)) {
         qCritical("QQnxVirtualKeyboard: Unable to allocate buffer of %d bytes. "
                   "Size is unavailable.",  ms_bufferSize);
         return false;
@@ -170,7 +170,7 @@ void QQnxVirtualKeyboardPps::ppsDataReady()
         return;
 
     // nread is the real space necessary, not the amount read.
-    if (static_cast<size_t>(nread) > ms_bufferSize - 1) {
+    if (Q_UNLIKELY(static_cast<size_t>(nread) > ms_bufferSize - 1)) {
         qCritical("QQnxVirtualKeyboard: Keyboard buffer size too short; need %u.", nread + 1);
         connect(); // reconnect
         return;
@@ -184,7 +184,7 @@ void QQnxVirtualKeyboardPps::ppsDataReady()
 #endif
 
     const char *value;
-    if (pps_decoder_get_string(m_decoder, "error", &value) == PPS_DECODER_OK) {
+    if (Q_UNLIKELY(pps_decoder_get_string(m_decoder, "error", &value) == PPS_DECODER_OK)) {
         qCritical("QQnxVirtualKeyboard: Keyboard PPS decoder error: %s", value ? value : "[null]");
         return;
     }
@@ -214,11 +214,11 @@ void QQnxVirtualKeyboardPps::handleKeyboardInfoMessage()
 {
     int newHeight = 0;
 
-    if (pps_decoder_push(m_decoder, "dat") != PPS_DECODER_OK) {
+    if (Q_UNLIKELY(pps_decoder_push(m_decoder, "dat") != PPS_DECODER_OK)) {
         qCritical("QQnxVirtualKeyboard: Keyboard PPS dat object not found");
         return;
     }
-    if (pps_decoder_get_int(m_decoder, "size", &newHeight) != PPS_DECODER_OK) {
+    if (Q_UNLIKELY(pps_decoder_get_int(m_decoder, "size", &newHeight) != PPS_DECODER_OK)) {
         qCritical("QQnxVirtualKeyboard: Keyboard PPS size field not found");
         return;
     }
diff --git a/src/plugins/platforms/qnx/qqnxwindow.cpp b/src/plugins/platforms/qnx/qqnxwindow.cpp
index c081aa6d28..6adc352e2d 100644
--- a/src/plugins/platforms/qnx/qqnxwindow.cpp
+++ b/src/plugins/platforms/qnx/qqnxwindow.cpp
@@ -372,7 +372,7 @@ void QQnxWindow::setBufferSize(const QSize &size)
         screen_get_window_property_iv(m_window, SCREEN_PROPERTY_RENDER_BUFFER_COUNT, &bufferCount),
         "Failed to query render buffer count");
 
-    if (bufferCount != MAX_BUFFER_COUNT) {
+    if (Q_UNLIKELY(bufferCount != MAX_BUFFER_COUNT)) {
         qFatal("QQnxWindow: invalid buffer count. Expected = %d, got = %d.",
                 MAX_BUFFER_COUNT, bufferCount);
     }
@@ -450,10 +450,10 @@ void QQnxWindow::removeFromParent()
     qWindowDebug() << Q_FUNC_INFO << "window =" << window();
     // Remove from old Hierarchy position
     if (m_parentWindow) {
-        if (m_parentWindow->m_childWindows.removeAll(this))
-            m_parentWindow = 0;
-        else
+        if (Q_UNLIKELY(!m_parentWindow->m_childWindows.removeAll(this)))
             qFatal("QQnxWindow: Window Hierarchy broken; window has parent, but parent hasn't got child.");
+        else
+            m_parentWindow = 0;
     } else if (m_screen) {
         m_screen->removeWindow(this);
     }