JIT: Compute fgCalledCount after synthesis

src/coreclr/jit/compiler.h

@@ -5398,9 +5398,9 @@ class Compiler
     // - Rationalization links all nodes into linear form which is kept until
     //   the end of compilation. The first and last nodes are stored in the block.
     NodeThreading fgNodeThreading = NodeThreading::None;
-    weight_t      fgCalledCount = BB_ZERO_WEIGHT;          // count of the number of times this method was called
-                                          // This is derived from the profile data
-                                          // or is BB_UNITY_WEIGHT when we don't have profile data
+    weight_t      fgCalledCount = BB_UNITY_WEIGHT; // count of the number of times this method was called
+                                                   // This is derived from the profile data
+                                                   // or is BB_UNITY_WEIGHT when we don't have profile data
 
     bool fgFuncletsCreated = false; // true if the funclet creation phase has been run
 

src/coreclr/jit/fgprofile.cpp

@@ -4222,19 +4222,9 @@ PhaseStatus Compiler::fgComputeBlockWeights()
 
     if (fgIsUsingProfileWeights())
     {
-        // Compute fgCalledCount by subtracting any non-entry flow into fgFirstBB from its weight
-        fgCalledCount = fgFirstBB->bbWeight;
-        for (FlowEdge* const predEdge : fgFirstBB->PredEdges())
-        {
-            fgCalledCount = max(BB_ZERO_WEIGHT, fgCalledCount - predEdge->getLikelyWeight());
-        }
-
-        JITDUMP("We are using the profile weights and fgCalledCount is " FMT_WT "\n", fgCalledCount);
         return PhaseStatus::MODIFIED_NOTHING;
     }
 
-    JITDUMP(" -- no profile data, so using default called count\n");
-    fgCalledCount = BB_UNITY_WEIGHT;
     return fgComputeMissingBlockWeights() ? PhaseStatus::MODIFIED_EVERYTHING : PhaseStatus::MODIFIED_NOTHING;
 }
 

src/coreclr/jit/fgprofilesynthesis.cpp

@@ -161,6 +161,20 @@ void ProfileSynthesis::Run(ProfileSynthesisOption option)
         m_comp->Metrics.ProfileInconsistentInitially++;
     }
 
+    // Derive the method's call count from the entry block's weight
+    //
+    if (m_comp->fgIsUsingProfileWeights() && !m_comp->compIsForInlining())
+    {
+        weight_t entryWeight = m_entryBlock->bbWeight;
+        for (FlowEdge* const predEdge : m_entryBlock->PredEdges())
+        {
+            entryWeight -= predEdge->getLikelyWeight();
+        }
+
+        m_comp->fgCalledCount = max(BB_ZERO_WEIGHT, entryWeight);
+        JITDUMP("fgCalledCount is " FMT_WT "\n", m_comp->fgCalledCount);
+    }
+
 #ifdef DEBUG
     // We want to assert that the profile is consistent.
     // However, we need to defer asserting since invalid IL can