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>

1 files changed, 12 insertions, 12 deletions

diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
index 1ddcb3b862..b364056b91 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_egldevice/qeglfskmsegldeviceintegration.cpp
@@ -52,20 +52,20 @@ QEglFSKmsEglDeviceIntegration::QEglFSKmsEglDeviceIntegration()
 
 void QEglFSKmsEglDeviceIntegration::platformInit()
 {
-    if (!query_egl_device())
+    if (Q_UNLIKELY(!query_egl_device()))
         qFatal("Could not set up EGL device!");
 
     const char *deviceName = m_funcs->query_device_string(m_egl_device, EGL_DRM_DEVICE_FILE_EXT);
-    if (!deviceName)
+    if (Q_UNLIKELY(!deviceName))
         qFatal("Failed to query device name from EGLDevice");
 
     qCDebug(qLcEglfsKmsDebug, "Opening %s", deviceName);
 
     m_dri_fd = drmOpen(deviceName, Q_NULLPTR);
-    if (m_dri_fd < 0)
+    if (Q_UNLIKELY(m_dri_fd < 0))
         qFatal("Could not open DRM device");
 
-    if (!setup_kms())
+    if (Q_UNLIKELY(!setup_kms()))
         qFatal("Could not set up KMS on device %s!", m_device.constData());
 
     qCDebug(qLcEglfsKmsDebug, "DRM/KMS initialized");
@@ -100,14 +100,14 @@ EGLDisplay QEglFSKmsEglDeviceIntegration::createDisplay(EGLNativeDisplayType nat
         display = eglGetDisplay(nativeDisplay);
     }
 
-    if (display == EGL_NO_DISPLAY)
+    if (Q_UNLIKELY(display == EGL_NO_DISPLAY))
         qFatal("Could not get EGL display");
 
     EGLint major, minor;
-    if (!eglInitialize(display, &major, &minor))
+    if (Q_UNLIKELY(!eglInitialize(display, &major, &minor)))
         qFatal("Could not initialize egl display");
 
-    if (!eglBindAPI(EGL_OPENGL_ES_API))
+    if (Q_UNLIKELY(!eglBindAPI(EGL_OPENGL_ES_API)))
         qFatal("Failed to bind EGL_OPENGL_ES_API\n");
 
     return display;
@@ -255,8 +255,8 @@ QEglFSWindow *QEglFSKmsEglDeviceIntegration::createWindow(QWindow *window) const
     QEglJetsonTK1Window *eglWindow = new QEglJetsonTK1Window(window, this);
 
     m_funcs->initialize(eglWindow->screen()->display());
-    if (!(m_funcs->has_egl_output_base && m_funcs->has_egl_output_drm && m_funcs->has_egl_stream
-          && m_funcs->has_egl_stream_producer_eglsurface && m_funcs->has_egl_stream_consumer_egloutput))
+    if (Q_UNLIKELY(!(m_funcs->has_egl_output_base && m_funcs->has_egl_output_drm && m_funcs->has_egl_stream &&
+                     m_funcs->has_egl_stream_producer_eglsurface && m_funcs->has_egl_stream_consumer_egloutput)))
         qFatal("Required extensions missing!");
 
     return eglWindow;
@@ -298,7 +298,7 @@ void QEglFSKmsEglDeviceIntegration::waitForVSync(QPlatformSurface *) const
                                  -1, 0, 0,
                                  &m_drm_connector->connector_id, 1,
                                  const_cast<const drmModeModeInfoPtr>(&m_drm_mode));
-        if (ret)
+        if (Q_UNLIKELY(ret))
             qFatal("drmModeSetCrtc failed");
     }
 }
@@ -367,7 +367,7 @@ bool QEglFSKmsEglDeviceIntegration::setup_kms()
         }
     }
 
-    if (crtc == 0)
+    if (Q_UNLIKELY(crtc == 0))
         qFatal("No suitable CRTC available");
 
     m_drm_connector = connector;
@@ -387,7 +387,7 @@ bool QEglFSKmsEglDeviceIntegration::setup_kms()
 bool QEglFSKmsEglDeviceIntegration::query_egl_device()
 {
     m_funcs = new QEGLStreamConvenience;
-    if (!m_funcs->has_egl_device_base)
+    if (Q_UNLIKELY(!m_funcs->has_egl_device_base))
         qFatal("EGL_EXT_device_base missing");
 
     EGLint num_devices = 0;