Disable split async pass when doing sync DispatchRays

When doing sync DispatchRays, we don't want to split TraceRay operations

Author: jaladreips

IGC/AdaptorCommon/RayTracing/RayTracingInterface.cpp

@@ -192,9 +192,12 @@ void RayTracingLowering(RayDispatchShaderContext* pContext)
         // multiple times.
         mpm.add(createRayInfoCSEPass());
     }
+
     // After this pass, all shaders with TraceRay() or CallShader() calls will
     // be split into continuations at those call sites.
-    mpm.add(createSplitAsyncPass());
+    if (!pContext->doSyncDispatchRays())
+        mpm.add(createSplitAsyncPass());
+
     if (IGC_IS_FLAG_DISABLED(DisablePromoteToScratch) &&
         pContext->m_DriverInfo.supportsRTScratchSpace())
     {

IGC/Compiler/CodeGenContext.cpp

@@ -1791,9 +1791,6 @@ namespace IGC
 
     bool RayDispatchShaderContext::requiresIndirectContinuationHandling() const
     {
-        IGC_ASSERT_MESSAGE(modMD->rtInfo.NumContinuations != UINT_MAX,
-            "not computed yet!");
-
         if (IGC_IS_FLAG_ENABLED(EnableInlinedContinuations) &&
             canWholeProgramCompile())
         {

IGC/common/MDFrameWork.h

@@ -228,9 +228,8 @@ namespace IGC
         uint32_t RayQueryAllocSizeInBytes = 0;
 
         // SplitAsyncPass sets the number of continuations that were generated.
-        // This is heuristically used to determine whether we should inline
-        // or indirectly BTD to the continuations.
-        uint32_t NumContinuations = UINT_MAX;
+        // However, with sync DispatchRays SplitAsyncPass is not guaranteed to run.
+        uint32_t NumContinuations = 0;
 
         // Track the address spaces and SSH offsets for indirect stateful
         // accesses.