Remove LOAD_CLOSURE instruction.

Author: markshannon

Include/opcode.h

@@ -181,8 +181,6 @@ def jabs_op(name, op):
 def_op('MAKE_FUNCTION', 132)    # Flags
 def_op('BUILD_SLICE', 133)      # Number of items
 
-def_op('LOAD_CLOSURE', 135)
-hasfree.append(135)
 def_op('LOAD_DEREF', 136)
 hasfree.append(136)
 def_op('STORE_DEREF', 137)

Lib/opcode.py

@@ -427,7 +427,7 @@ def foo(x):
     return foo
 
 dis_nested_0 = """\
-%3d           0 LOAD_CLOSURE             2 (y)
+%3d           0 LOAD_FAST                2 (y)
               2 BUILD_TUPLE              1
               4 LOAD_CONST               1 (<code object foo at 0x..., file "%s", line %d>)
               6 LOAD_CONST               2 ('_h.<locals>.foo')
@@ -444,7 +444,7 @@ def foo(x):
 
 dis_nested_1 = """%s
 Disassembly of <code object foo at 0x..., file "%s", line %d>:
-%3d           0 LOAD_CLOSURE             1 (x)
+%3d           0 LOAD_FAST                1 (x)
               2 BUILD_TUPLE              1
               4 LOAD_CONST               1 (<code object <listcomp> at 0x..., file "%s", line %d>)
               6 LOAD_CONST               2 ('_h.<locals>.foo.<locals>.<listcomp>')
@@ -962,8 +962,8 @@ def jumpy():
 Instruction = dis.Instruction
 expected_opinfo_outer = [
   Instruction(opname='LOAD_CONST', opcode=100, arg=8, argval=(3, 4), argrepr='(3, 4)', offset=0, starts_line=2, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=3, argval='a', argrepr='a', offset=2, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=4, argval='b', argrepr='b', offset=4, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=3, argval='a', argrepr='a', offset=2, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=4, argval='b', argrepr='b', offset=4, starts_line=None, is_jump_target=False),
   Instruction(opname='BUILD_TUPLE', opcode=102, arg=2, argval=2, argrepr='', offset=6, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=code_object_f, argrepr=repr(code_object_f), offset=8, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='outer.<locals>.f', argrepr="'outer.<locals>.f'", offset=10, starts_line=None, is_jump_target=False),
@@ -985,10 +985,10 @@ def jumpy():
 
 expected_opinfo_f = [
   Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=(5, 6), argrepr='(5, 6)', offset=0, starts_line=3, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=5, argval='a', argrepr='a', offset=2, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=6, argval='b', argrepr='b', offset=4, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=3, argval='c', argrepr='c', offset=6, starts_line=None, is_jump_target=False),
-  Instruction(opname='LOAD_CLOSURE', opcode=135, arg=4, argval='d', argrepr='d', offset=8, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=5, argval='a', argrepr='a', offset=2, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=6, argval='b', argrepr='b', offset=4, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=3, argval='c', argrepr='c', offset=6, starts_line=None, is_jump_target=False),
+  Instruction(opname='LOAD_FAST', opcode=124, arg=4, argval='d', argrepr='d', offset=8, starts_line=None, is_jump_target=False),
   Instruction(opname='BUILD_TUPLE', opcode=102, arg=4, argval=4, argrepr='', offset=10, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=code_object_inner, argrepr=repr(code_object_inner), offset=12, starts_line=None, is_jump_target=False),
   Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='outer.<locals>.f.<locals>.inner', argrepr="'outer.<locals>.f.<locals>.inner'", offset=14, starts_line=None, is_jump_target=False),

Lib/test/test_dis.py

@@ -3070,13 +3070,6 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
             goto error;
         }
 
-        case TARGET(LOAD_CLOSURE): {
-            PyObject *cell = GETLOCAL(oparg);
-            Py_INCREF(cell);
-            PUSH(cell);
-            DISPATCH();
-        }
-
         case TARGET(LOAD_CLASSDEREF): {
             PyObject *name, *value, *locals = LOCALS();
             assert(locals);

Python/ceval.c

@@ -76,6 +76,9 @@
 #define SETUP_WITH 253
 #define POP_BLOCK 252
 
+/* Artificial instruction, will be converted to LOAD_FAST */
+#define LOAD_CLOSURE 251
+
 #define IS_TOP_LEVEL_AWAIT(c) ( \
         (c->c_flags->cf_flags & PyCF_ALLOW_TOP_LEVEL_AWAIT) \
         && (c->u->u_ste->ste_type == ModuleBlock))
@@ -1185,8 +1188,6 @@ stack_effect(int opcode, int oparg, int jump)
                 return -1;
 
         /* Closures */
-        case LOAD_CLOSURE:
-            return 1;
         case LOAD_DEREF:
         case LOAD_CLASSDEREF:
             return 1;
@@ -7436,17 +7437,19 @@ guarantee_lineno_for_exits(struct assembler *a, int firstlineno) {
 }
 
 static void
-offset_derefs(struct assembler *a, int nlocals)
+offset_derefs(basicblock *entryblock, int nlocals)
 {
-    for (basicblock *b = a->a_entry; b != NULL; b = b->b_next) {
+    for (basicblock *b = entryblock; b != NULL; b = b->b_next) {
         for (int i = 0; i < b->b_iused; i++) {
             struct instr *inst = &b->b_instr[i];
             switch(inst->i_opcode) {
+                case LOAD_CLOSURE:
+                    inst->i_opcode = LOAD_FAST;
+                    /* fall through */
                 case LOAD_DEREF:
                 case STORE_DEREF:
                 case DELETE_DEREF:
                 case LOAD_CLASSDEREF:
-                case LOAD_CLOSURE:
                     inst->i_oparg += nlocals;
             }
         }
@@ -7508,6 +7511,9 @@ assemble(struct compiler *c, int addNone)
     a.a_entry = entryblock;
     a.a_nblocks = nblocks;
 
+    assert(PyDict_GET_SIZE(c->u->u_varnames) < INT_MAX);
+    offset_derefs(entryblock, (int)PyDict_GET_SIZE(c->u->u_varnames));
+
     consts = consts_dict_keys_inorder(c->u->u_consts);
     if (consts == NULL) {
         goto error;
@@ -7517,8 +7523,6 @@ assemble(struct compiler *c, int addNone)
     }
     guarantee_lineno_for_exits(&a, c->u->u_firstlineno);
 
-    offset_derefs(&a, (int)PyDict_GET_SIZE(c->u->u_varnames));
-
     int maxdepth = stackdepth(c);
     if (maxdepth < 0) {
         goto error;