bpo-43693: Compute deref offsets in compiler (gh-25152)

Merges locals and cells into a single array.
Saves a pointer in the interpreter and means that we don't need the LOAD_CLOSURE opcode any more

https://bugs.python.org/issue43693

2 files changed, 8 insertions, 23 deletions

diff --git a/Objects/clinic/codeobject.c.h b/Objects/clinic/codeobject.c.h
index 629d265..c1ad09c 100644
--- a/Objects/clinic/codeobject.c.h
+++ b/Objects/clinic/codeobject.c.h
@@ -375,7 +375,7 @@ exit:
 }
 
 PyDoc_STRVAR(code__varname_from_oparg__doc__,
-"_varname_from_oparg($self, /, oparg, *, cell=False)\n"
+"_varname_from_oparg($self, /, oparg)\n"
 "--\n"
 "\n"
 "(internal-only) Return the local variable name for the given oparg.\n"
@@ -386,18 +386,16 @@ PyDoc_STRVAR(code__varname_from_oparg__doc__,
     {"_varname_from_oparg", (PyCFunction)(void(*)(void))code__varname_from_oparg, METH_FASTCALL|METH_KEYWORDS, code__varname_from_oparg__doc__},
 
 static PyObject *
-code__varname_from_oparg_impl(PyCodeObject *self, int oparg, int cell);
+code__varname_from_oparg_impl(PyCodeObject *self, int oparg);
 
 static PyObject *
 code__varname_from_oparg(PyCodeObject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
 {
     PyObject *return_value = NULL;
-    static const char * const _keywords[] = {"oparg", "cell", NULL};
+    static const char * const _keywords[] = {"oparg", NULL};
     static _PyArg_Parser _parser = {NULL, _keywords, "_varname_from_oparg", 0};
-    PyObject *argsbuf[2];
-    Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
+    PyObject *argsbuf[1];
     int oparg;
-    int cell = 0;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
     if (!args) {
@@ -407,17 +405,9 @@ code__varname_from_oparg(PyCodeObject *self, PyObject *const *args, Py_ssize_t n
     if (oparg == -1 && PyErr_Occurred()) {
         goto exit;
     }
-    if (!noptargs) {
-        goto skip_optional_kwonly;
-    }
-    cell = PyObject_IsTrue(args[1]);
-    if (cell < 0) {
-        goto exit;
-    }
-skip_optional_kwonly:
-    return_value = code__varname_from_oparg_impl(self, oparg, cell);
+    return_value = code__varname_from_oparg_impl(self, oparg);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=43f4eef80d584fe0 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=ba4c5487e0364ce8 input=a9049054013a1b77]*/
diff --git a/Objects/codeobject.c b/Objects/codeobject.c
index 051aefe..b82a1b5 100644
--- a/Objects/codeobject.c
+++ b/Objects/codeobject.c
@@ -1547,8 +1547,6 @@ error:
 code._varname_from_oparg
 
     oparg: int
-    *
-    cell: bool = False
 
 (internal-only) Return the local variable name for the given oparg.
 
@@ -1556,12 +1554,9 @@ WARNING: this method is for internal use only and may change or go away.
 [clinic start generated code]*/
 
 static PyObject *
-code__varname_from_oparg_impl(PyCodeObject *self, int oparg, int cell)
-/*[clinic end generated code: output=c7d39c9723692c8f input=2945bb291d3a3118]*/
+code__varname_from_oparg_impl(PyCodeObject *self, int oparg)
+/*[clinic end generated code: output=1fd1130413184206 input=c5fa3ee9bac7d4ca]*/
 {
-    if (cell) {
-        oparg += self->co_nlocals;
-    }
     PyObject *name = PyTuple_GetItem(self->co_localsplusnames, oparg);
     if (name == NULL) {
         return NULL;