[all] provide conditional path optimization hints to the compiler

client/renderers/EGL/desktop.c

@@ -382,9 +382,9 @@ bool egl_desktopSetup(EGL_Desktop * desktop, const LG_RendererFormat format)
 bool egl_desktopUpdate(EGL_Desktop * desktop, const FrameBuffer * frame, int dmaFd,
     const FrameDamageRect * damageRects, int damageRectsCount)
 {
-  if (desktop->useDMA && dmaFd >= 0)
+  if (likely(desktop->useDMA && dmaFd >= 0))
   {
-    if (egl_textureUpdateFromDMA(desktop->texture, frame, dmaFd))
+    if (likely(egl_textureUpdateFromDMA(desktop->texture, frame, dmaFd)))
     {
       atomic_store(&desktop->processFrame, true);
       return true;
@@ -420,8 +420,8 @@ bool egl_desktopUpdate(EGL_Desktop * desktop, const FrameBuffer * frame, int dma
       return false;
   }
 
-  if (egl_textureUpdateFromFrame(desktop->texture, frame,
-        damageRects, damageRectsCount))
+  if (likely(egl_textureUpdateFromFrame(desktop->texture, frame,
+        damageRects, damageRectsCount)))
   {
     atomic_store(&desktop->processFrame, true);
     return true;
@@ -443,7 +443,7 @@ bool egl_desktopRender(EGL_Desktop * desktop, unsigned int outputWidth,
   EGL_Texture * tex;
   int width, height;
 
-  if (desktop->useSpice)
+  if (unlikely(desktop->useSpice))
   {
     tex    = desktop->spiceTexture;
     width  = desktop->spiceWidth;
@@ -456,11 +456,11 @@ bool egl_desktopRender(EGL_Desktop * desktop, unsigned int outputWidth,
     height = desktop->height;
   }
 
-  if (outputWidth == 0 && outputHeight == 0)
+  if (unlikely(outputWidth == 0 && outputHeight == 0))
     DEBUG_FATAL("outputWidth || outputHeight == 0");
 
   enum EGL_TexStatus status;
-  if ((status = egl_textureProcess(tex)) != EGL_TEX_STATUS_OK)
+  if (unlikely((status = egl_textureProcess(tex)) != EGL_TEX_STATUS_OK))
   {
     if (status != EGL_TEX_STATUS_NOTREADY)
       DEBUG_ERROR("Failed to process the desktop texture");

client/renderers/EGL/desktop_rects.c

@@ -296,7 +296,7 @@ bool egl_screenToDesktop(struct FrameDamageRect * output, const double matrix[6]
 
 void egl_desktopRectsRender(EGL_DesktopRects * rects)
 {
-  if (!rects->count)
+  if (unlikely(!rects->count))
     return;
 
   glBindVertexArray(rects->vao);

client/renderers/EGL/egl.c

@@ -20,6 +20,7 @@
 
 #include "interface/renderer.h"
 
+#include "common/util.h"
 #include "common/debug.h"
 #include "common/KVMFR.h"
 #include "common/option.h"
@@ -580,7 +581,7 @@ static bool egl_onFrameFormat(LG_Renderer * renderer, const LG_RendererFormat fo
   this->formatValid = true;
 
   /* this event runs in a second thread so we need to init it here */
-  if (!this->frameContext)
+  if (unlikely(!this->frameContext))
   {
     static EGLint attrs[] = {
       EGL_CONTEXT_CLIENT_VERSION, 2,
@@ -600,7 +601,7 @@ static bool egl_onFrameFormat(LG_Renderer * renderer, const LG_RendererFormat fo
     }
   }
 
-  if (this->scalePointer)
+  if (likely(this->scalePointer))
   {
     float scale = max(1.0f, (float)format.screenWidth / this->width);
     egl_cursorSetScale(this->cursor, scale);
@@ -623,7 +624,8 @@ static bool egl_onFrame(LG_Renderer * renderer, const FrameBuffer * frame, int d
   struct Inst * this = UPCAST(struct Inst, renderer);
 
   uint64_t start = nanotime();
-  if (!egl_desktopUpdate(this->desktop, frame, dmaFd, damageRects, damageRectsCount))
+  if (unlikely(!egl_desktopUpdate(
+          this->desktop, frame, dmaFd, damageRects, damageRectsCount)))
   {
     DEBUG_INFO("Failed to to update the desktop");
     return false;
@@ -632,12 +634,17 @@ static bool egl_onFrame(LG_Renderer * renderer, const FrameBuffer * frame, int d
 
   INTERLOCKED_SECTION(this->desktopDamageLock, {
     struct DesktopDamage * damage = this->desktopDamage + this->desktopDamageIdx;
-    if (damage->count == -1 || damageRectsCount == 0 ||
-        damage->count + damageRectsCount >= KVMFR_MAX_DAMAGE_RECTS)
+    if (unlikely(
+        damage->count                    == -1 ||
+        damageRectsCount                 == 0 ||
+        damage->count + damageRectsCount >= KVMFR_MAX_DAMAGE_RECTS))
+    {
       damage->count = -1;
+    }
     else
     {
-      memcpy(damage->rects + damage->count, damageRects, damageRectsCount * sizeof(FrameDamageRect));
+      memcpy(damage->rects + damage->count, damageRects,
+          damageRectsCount * sizeof(FrameDamageRect));
       damage->count += damageRectsCount;
     }
   });
@@ -1056,14 +1063,14 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
   accumulated->count = 0;
 
   INTERLOCKED_SECTION(this->desktopDamageLock, {
-    if (!renderAll)
+    if (likely(!renderAll))
     {
       for (int i = 0; i < bufferAge; ++i)
       {
         struct DesktopDamage * damage = this->desktopDamage +
             IDX_AGO(this->desktopDamageIdx, i, DESKTOP_DAMAGE_COUNT);
 
-        if (damage->count < 0)
+        if (unlikely(damage->count < 0))
         {
           renderAll = true;
           break;
@@ -1087,7 +1094,7 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
     this->desktopDamage[this->desktopDamageIdx].count = 0;
   });
 
-  if (!renderAll)
+  if (likely(!renderAll))
   {
     double matrix[6];
     egl_screenToDesktopMatrix(matrix,
@@ -1101,7 +1108,7 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
       int count = this->overlayHistoryCount[idx];
       struct Rect * damage = this->overlayHistory[idx];
 
-      if (count < 0)
+      if (unlikely(count < 0))
       {
         renderAll = true;
         break;
@@ -1114,11 +1121,12 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
         );
     }
 
-    accumulated->count = rectsMergeOverlapping(accumulated->rects, accumulated->count);
+    accumulated->count = rectsMergeOverlapping(accumulated->rects,
+        accumulated->count);
   }
   ++this->overlayHistoryIdx;
 
-  if (this->destRect.w > 0 && this->destRect.h > 0)
+  if (likely(this->destRect.w > 0 && this->destRect.h > 0))
   {
     if (egl_desktopRender(this->desktop,
         this->destRect.w, this->destRect.h,
@@ -1136,20 +1144,17 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
 
   renderLetterBox(this);
 
-  hasOverlay |= egl_damageRender(this->damage, rotate, newFrame ? desktopDamage : NULL);
-  hasOverlay |= invalidateWindow;
+  hasOverlay |=
+    egl_damageRender(this->damage, rotate, newFrame ? desktopDamage : NULL) |
+    invalidateWindow;
 
   struct Rect damage[KVMFR_MAX_DAMAGE_RECTS + MAX_OVERLAY_RECTS + 2];
   int damageIdx = app_renderOverlay(damage, MAX_OVERLAY_RECTS);
-
-  switch (damageIdx)
+  if (unlikely(damageIdx != 0))
   {
-    case 0: // no overlay
-      break;
-    case -1: // full damage
+    if (damageIdx == -1)
       hasOverlay = true;
-      // fallthrough
-    default:
+
     ImGui_ImplOpenGL3_NewFrame();
     ImGui_ImplOpenGL3_RenderDrawData(igGetDrawData());
 
@@ -1157,20 +1162,21 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
       damage[i].y = this->height - damage[i].y - damage[i].h;
   }
 
-  if (damageIdx >= 0 && cursorState.visible)
+  if (likely(damageIdx >= 0 && cursorState.visible))
     damage[damageIdx++] = cursorState.rect;
 
   int overlayHistoryIdx = this->overlayHistoryIdx % DESKTOP_DAMAGE_COUNT;
-  if (hasOverlay)
+  if (unlikely(hasOverlay))
     this->overlayHistoryCount[overlayHistoryIdx] = -1;
   else
   {
-    if (damageIdx > 0)
-      memcpy(this->overlayHistory[overlayHistoryIdx], damage, damageIdx * sizeof(struct Rect));
+    if (unlikely(damageIdx > 0))
+      memcpy(this->overlayHistory[overlayHistoryIdx],
+          damage, damageIdx * sizeof(struct Rect));
     this->overlayHistoryCount[overlayHistoryIdx] = damageIdx;
   }
 
-  if (!hasOverlay && !this->hadOverlay)
+  if (unlikely(!hasOverlay && !this->hadOverlay))
   {
     if (this->cursorLast.visible)
       damage[damageIdx++] = this->cursorLast.rect;
@@ -1197,7 +1203,9 @@ static bool egl_render(LG_Renderer * renderer, LG_RendererRotate rotate,
   this->cursorLast = cursorState;
 
   preSwap(udata);
-  app_eglSwapBuffers(this->display, this->surface, damage, this->noSwapDamage ? 0 : damageIdx);
+  app_eglSwapBuffers(this->display, this->surface, damage,
+      this->noSwapDamage ? 0 : damageIdx);
+
   return true;
 }
 

client/renderers/EGL/texture_dmabuf.c

@@ -157,7 +157,7 @@ static bool egl_texDMABUFUpdate(EGL_Texture * texture,
       break;
     }
 
-  if (image == EGL_NO_IMAGE)
+  if (unlikely(image == EGL_NO_IMAGE))
   {
     const uint64_t modifier = DRM_FORMAT_MOD_LINEAR;
     EGLAttrib attribs[] =
@@ -184,16 +184,16 @@ static bool egl_texDMABUFUpdate(EGL_Texture * texture,
         (EGLClientBuffer)NULL,
         attribs);
 
-    if (image == EGL_NO_IMAGE)
+    if (unlikely(image == EGL_NO_IMAGE))
     {
       DEBUG_EGL_ERROR("Failed to create EGLImage for DMA transfer");
       return false;
     }
 
-    if (!vector_push(&this->images, &(struct FdImage) {
+    if (unlikely(!vector_push(&this->images, &(struct FdImage) {
       .fd    = update->dmaFD,
       .image = image,
-    }))
+    })))
     {
       DEBUG_ERROR("Failed to store EGLImage");
       g_egl_dynProcs.eglDestroyImage(this->display, image);
@@ -206,7 +206,7 @@ static bool egl_texDMABUFUpdate(EGL_Texture * texture,
     glBindTexture(GL_TEXTURE_EXTERNAL_OES, parent->tex[parent->bufIndex]);
     g_egl_dynProcs.glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, image);
 
-    if (parent->sync)
+    if (likely(parent->sync))
       glDeleteSync(parent->sync);
 
     parent->sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);

client/src/main.c

@@ -209,17 +209,16 @@ static int renderThread(void * unused)
   struct timespec time;
   clock_gettime(CLOCK_MONOTONIC, &time);
 
-  while(g_state.state != APP_STATE_SHUTDOWN)
+  while(likely(g_state.state != APP_STATE_SHUTDOWN))
   {
-    bool forceRender = false;
     if (g_state.jitRender)
-      forceRender = g_state.ds->waitFrame();
-
+    {
+      const bool forceRender = g_state.ds->waitFrame();
       app_handleRenderEvent(microtime());
-    if (g_state.jitRender)
-    {
+
       const uint64_t pending =
         atomic_load_explicit(&g_state.pendingCount, memory_order_acquire);
+
       if (!lgResetEvent(g_state.frameEvent)
           && !forceRender
           && !pending
@@ -235,9 +234,13 @@ static int renderThread(void * unused)
     }
     else if (g_params.fpsMin != 0)
     {
+      app_handleRenderEvent(microtime());
+
       float ups = atomic_load_explicit(&g_state.ups, memory_order_relaxed);
 
-      if (!lgWaitEventAbs(g_state.frameEvent, &time) || ups > g_params.fpsMin)
+      if (unlikely(
+            !lgWaitEventAbs(g_state.frameEvent, &time) ||
+            ups > g_params.fpsMin))
       {
         /* only update the time if we woke up early */
         clock_gettime(CLOCK_MONOTONIC, &time);
@@ -247,7 +250,7 @@ static int renderThread(void * unused)
     }
 
     int resize = atomic_load(&g_state.lgrResize);
-    if (resize)
+    if (unlikely(resize))
     {
       g_state.io->DisplaySize = (ImVec2) {
         .x = g_state.windowW,
@@ -286,8 +289,8 @@ static int renderThread(void * unused)
 
     renderQueue_process();
 
-    if (!RENDERER(render, g_params.winRotate, newFrame, invalidate,
-          preSwapCallback, (void *)&renderStart))
+    if (unlikely(!RENDERER(render, g_params.winRotate, newFrame, invalidate,
+          preSwapCallback, (void *)&renderStart)))
     {
       LG_UNLOCK(g_state.lgrLock);
       break;
@@ -300,7 +303,7 @@ static int renderThread(void * unused)
     g_state.lastRenderTime = t;
     atomic_fetch_add_explicit(&g_state.renderCount, 1, memory_order_relaxed);
 
-    if (g_state.lastRenderTimeValid)
+    if (likely(g_state.lastRenderTimeValid))
     {
       const float fdelta = (float)delta / 1e6f;
       ringbuffer_push(g_state.renderTimings, &fdelta);
@@ -308,7 +311,9 @@ static int renderThread(void * unused)
     g_state.lastRenderTimeValid = true;
 
     const uint64_t now = microtime();
-    if (!g_state.resizeDone && g_state.resizeTimeout < now)
+    if (unlikely(
+          !g_state.resizeDone &&
+          g_state.resizeTimeout < now))
     {
       if (g_params.autoResize)
       {
@@ -1739,9 +1744,9 @@ restart:
     return -1;
   }
 
-  while(g_state.state == APP_STATE_RUNNING)
+  while(likely(g_state.state == APP_STATE_RUNNING))
   {
-    if (!lgmpClientSessionValid(g_state.lgmp))
+    if (unlikely(!lgmpClientSessionValid(g_state.lgmp)))
     {
       g_state.lgHostConnected = false;
       DEBUG_INFO("Waiting for the host to restart...");

common/include/common/util.h

@@ -40,4 +40,7 @@
 
 #define ALIGN_TO(value, align) (((value) + (align) - 1) & -(align))
 
+#define unlikely(expr) __builtin_expect(!!(expr), 0)
+#define likely(expr)   __builtin_expect(!!(expr), 1)
+
 #endif

host/platform/Windows/capture/NVFBC/src/nvfbc.c

@@ -457,7 +457,7 @@ static CaptureResult nvfbc_capture(void)
 
   unsigned int width, height;
   getDesktopSize(&width, &height);
-  if (this->width != width || this->height != height)
+  if (unlikely(this->width != width || this->height != height))
   {
     this->resChanged = true;
     this->width      = width;
@@ -476,7 +476,7 @@ static CaptureResult nvfbc_capture(void)
     &grabInfo
   );
 
-  if (result != CAPTURE_RESULT_OK)
+  if (unlikely(result != CAPTURE_RESULT_OK))
     return result;
 
   bool changed = false;
@@ -651,15 +651,15 @@ done:
 static CaptureResult nvfbc_waitFrame(CaptureFrame * frame,
     const size_t maxFrameSize)
 {
-  if (this->stop)
+  if (unlikely(this->stop))
     return CAPTURE_RESULT_REINIT;
 
-  if (
+  if (unlikely(
     this->grabInfo.dwWidth       != this->grabWidth  ||
     this->grabInfo.dwHeight      != this->grabHeight ||
     this->grabInfo.dwBufferWidth != this->grabStride ||
     this->grabInfo.bIsHDR        != this->isHDR      ||
-    this->resChanged)
+    this->resChanged))
   {
     this->grabWidth  = this->grabInfo.dwWidth;
     this->grabHeight = this->grabInfo.dwHeight;
@@ -820,11 +820,11 @@ static CaptureResult nvfbc_getFrame(FrameBuffer * frame, int frameIndex)
 
 static int pointerThread(void * unused)
 {
-  while (!this->stop)
+  while (likely(!this->stop))
   {
     lgWaitEvent(this->cursorEvent, TIMEOUT_INFINITE);
 
-    if (this->stop)
+    if (unlikely(this->stop))
       break;
 
     CaptureResult  result;
@@ -832,14 +832,14 @@ static int pointerThread(void * unused)
 
     void * data;
     uint32_t size;
-    if (!this->getPointerBufferFn(&data, &size))
+    if (unlikely(!this->getPointerBufferFn(&data, &size)))
     {
       DEBUG_WARN("failed to get a pointer buffer");
       continue;
     }
 
     result = NvFBCToSysGetCursor(this->nvfbc, &pointer, data, size);
-    if (result != CAPTURE_RESULT_OK)
+    if (unlikely(result != CAPTURE_RESULT_OK))
     {
       DEBUG_WARN("NvFBCToSysGetCursor failed");
       continue;

host/src/app.c

@@ -927,14 +927,16 @@ int app_main(int argc, char * argv[])
       }
     }
 
-    while(app.state != APP_STATE_SHUTDOWN && (
+    while(likely(app.state != APP_STATE_SHUTDOWN && (
           lgmpHostQueueHasSubs(app.pointerQueue) ||
-          lgmpHostQueueHasSubs(app.frameQueue)))
+          lgmpHostQueueHasSubs(app.frameQueue))))
     {
-      if (app.state == APP_STATE_RESTART || app.state == APP_STATE_REINIT)
+      if (unlikely(
+            app.state == APP_STATE_RESTART ||
+            app.state == APP_STATE_REINIT))
         break;
 
-      if (lgmpHostQueueNewSubs(app.pointerQueue) > 0)
+      if (unlikely(lgmpHostQueueNewSubs(app.pointerQueue) > 0))
       {
         LG_LOCK(app.pointerLock);
         sendPointer(true);
@@ -951,24 +953,25 @@ int app_main(int argc, char * argv[])
       }
 
       const uint64_t captureStart = microtime();
-      switch(app.iface->capture())
-      {
-        case CAPTURE_RESULT_OK:
+      const CaptureResult result = app.iface->capture();
+      if (likely(result == CAPTURE_RESULT_OK))
         previousFrameTime = captureStart;
-          break;
-
-        case CAPTURE_RESULT_TIMEOUT:
+      else if (likely(result == CAPTURE_RESULT_TIMEOUT))
+      {
         if (!app.iface->asyncCapture)
-            if (app.frameValid && lgmpHostQueueNewSubs(app.frameQueue) > 0)
+          if (unlikely(app.frameValid &&
+                lgmpHostQueueNewSubs(app.frameQueue) > 0))
           {
             LGMP_STATUS status;
             if ((status = lgmpHostQueuePost(app.frameQueue, 0,
                     app.frameMemory[app.frameIndex])) != LGMP_OK)
               DEBUG_ERROR("%s", lgmpStatusString(status));
           }
-
-          continue;
-
+      }
+      else
+      {
+        switch(result)
+        {
           case CAPTURE_RESULT_REINIT:
             app.state = APP_STATE_RESTART;
             continue;
@@ -977,6 +980,10 @@ int app_main(int argc, char * argv[])
             DEBUG_ERROR("Capture interface reported a fatal error");
             exitcode = LG_HOST_EXIT_FAILED;
             goto fail_capture;
+
+          default:
+            DEBUG_ASSERT("Invalid capture result");
+        }
       }
 
       if (!app.iface->asyncCapture)