[draft] register machine

Include/cpython/code.h

@@ -22,10 +22,16 @@ typedef union {
         uint8_t opcode;
         uint8_t oparg;
     };
+    struct {
+        uint8_t oparg2;
+        uint8_t oparg3;
+    };
 } _Py_CODEUNIT;
 
 #define _Py_OPCODE(word) ((word).opcode)
 #define _Py_OPARG(word) ((word).oparg)
+#define _Py_OPARG2(word) ((word).oparg2)
+#define _Py_OPARG3(word) ((word).oparg3)
 
 static inline void
 _py_set_opcode(_Py_CODEUNIT *word, uint8_t opcode)

Include/internal/pycore_frame.h

@@ -223,6 +223,13 @@ _PyFrame_PushUnchecked(PyThreadState *tstate, PyFunctionObject *func)
     tstate->datastack_top += code->co_framesize;
     assert(tstate->datastack_top < tstate->datastack_limit);
     _PyFrame_InitializeSpecials(new_frame, func, NULL, code);
+    int nconsts = (int)PyTuple_Size(code->co_consts);
+    if (nconsts > 0) {
+        PyObject **const_regs = new_frame->localsplus + (code->co_nlocalsplus +
+                                                         code->co_stacksize);
+        PyObject **consts = &PyTuple_GET_ITEM(code->co_consts, 0);
+        memcpy(const_regs, consts, sizeof(PyObject*) * nconsts);
+    }
     return new_frame;
 }