1 files changed, 75 insertions, 0 deletions
diff --git a/src/jit/sm.h b/src/jit/sm.h
new file mode 100644
index 0000000000..33d65092bb
--- /dev/null
+++ b/src/jit/sm.h
@@ -0,0 +1,75 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+//
+// State machine header used ONLY in the JIT.
+//
+
+#ifndef __sm_h__
+#define __sm_h__
+
+#include "smcommon.h"
+
+extern const SMState*       gp_SMStates;
+extern const JumpTableCell* gp_SMJumpTableCells;
+extern const short*         gp_StateWeights;
+
+class CodeSeqSM // Represent a particualr run of the state machine
+                // For example, it maintains the array of counts for the terminated states.
+                // These counts should be stored in per method based for them to be correct
+                // under multithreadeded environment.
+{
+public:
+    Compiler* pComp;
+
+    const SMState*       States;
+    const JumpTableCell* JumpTableCells;
+    const short*         StateWeights; // Weight for each state. Including non-terminate states.
+
+    SM_STATE_ID curState;
+
+    int NativeSize; // This is a signed integer!
+
+    void Start(Compiler* comp);
+    void Reset();
+    void End();
+    void Run(SM_OPCODE opcode DEBUGARG(int level));
+
+    SM_STATE_ID GetDestState(SM_STATE_ID srcState, SM_OPCODE opcode);
+
+    // Matched a termination state
+    inline void TermStateMatch(SM_STATE_ID stateID DEBUGARG(bool verbose))
+    {
+        assert(States[stateID].term);
+        assert(StateMatchedCounts[stateID] < _UI16_MAX);
+#ifdef DEBUG
+        ++StateMatchedCounts[stateID];
+#ifndef SMGEN_COMPILE
+        if (verbose)
+        {
+            printf("weight=%3d : state %3d [ %s ]\n", StateWeights[stateID], stateID, StateDesc(stateID));
+        }
+#endif // SMGEN_COMPILE
+#endif // DEBUG
+
+        NativeSize += StateWeights[stateID];
+    }
+
+    // Given an SM opcode retrieve the weight for this single opcode state.
+    // For example, ID for single opcode state SM_NOSHOW is 2.
+    inline short GetWeightForOpcode(SM_OPCODE opcode)
+    {
+        SM_STATE_ID stateID = ((SM_STATE_ID)opcode) + SM_STATE_ID_START + 1;
+        return StateWeights[stateID];
+    }
+
+#ifdef DEBUG
+    WORD        StateMatchedCounts[NUM_SM_STATES];
+    const char* StateDesc(SM_STATE_ID stateID);
+#endif
+
+    static SM_OPCODE MapToSMOpcode(OPCODE opcode);
+};
+
+#endif /* __sm_h__ */