Exclude tail call counts from check to prevent unnecessary EBP frame

src/coreclr/jit/compiler.h

@@ -7091,9 +7091,11 @@ class Compiler
     bool fgHasLoops = false;
 
 protected:
-    unsigned optCallCount = 0;         // number of calls made in the method
-    unsigned optIndirectCallCount = 0; // number of virtual, interface and indirect calls made in the method
-    unsigned optNativeCallCount = 0;   // number of Pinvoke/Native calls made in the method
+    unsigned optCallCount = 0;                 // number of calls made in the method
+    unsigned optIndirectCallCount = 0;         // number of virtual, interface and indirect calls made in the method
+    unsigned optNativeCallCount = 0;           // number of Pinvoke/Native calls made in the method
+    unsigned optFastTailCallCount = 0;         // number of fast tail calls made in the method
+    unsigned optIndirectFastTailCallCount = 0; // number of indirect (see above) fast tail calls made in the method
 
 #ifdef DEBUG
     void optCheckPreds();

src/coreclr/jit/morph.cpp

@@ -6374,6 +6374,11 @@ GenTree* Compiler::fgMorphCall(GenTreeCall* call)
         {
             optCallCount++;
             optIndirectCallCount++;
+            if (call->IsFastTailCall())
+            {
+                optFastTailCallCount++;
+                optIndirectFastTailCallCount++;
+            }
         }
         else if (call->gtCallType == CT_USER_FUNC)
         {
@@ -6382,6 +6387,14 @@ GenTree* Compiler::fgMorphCall(GenTreeCall* call)
             {
                 optIndirectCallCount++;
             }
+            if (call->IsFastTailCall())
+            {
+                optFastTailCallCount++;
+                if (call->IsVirtual())
+                {
+                    optIndirectFastTailCallCount++;
+                }
+            }
         }
     }
 

src/coreclr/jit/regalloc.cpp

@@ -136,12 +136,12 @@ bool Compiler::rpMustCreateEBPFrame(INDEBUG(const char** wbReason))
         INDEBUG(reason = "Method has Loops");
         result = true;
     }
-    if (!result && (optCallCount >= 2))
+    if (!result && (optCallCount >= optFastTailCallCount + 2))
     {
         INDEBUG(reason = "Call Count");
         result = true;
     }
-    if (!result && (optIndirectCallCount >= 1))
+    if (!result && (optIndirectCallCount >= optIndirectFastTailCallCount + 1))
     {
         INDEBUG(reason = "Indirect Call");
         result = true;