mirror of
https://github.com/python/cpython.git
synced 2025-10-31 13:41:24 +00:00
Issue #2183: Simplify and optimize bytecode for list comprehensions.
This commit is contained in:
Antoine Pitrou
parent
43caaa09ea
commit
d0c3515bc5
9 changed files with 34 additions and 63 deletions
|
|
@ -463,9 +463,11 @@ Miscellaneous opcodes.
|
|||
address to jump to (which should be a ``FOR_ITER`` instruction).
|
||||
|
||||
|
||||
.. opcode:: LIST_APPEND ()
|
||||
.. opcode:: LIST_APPEND (i)
|
||||
|
||||
Calls ``list.append(TOS1, TOS)``. Used to implement list comprehensions.
|
||||
Calls ``list.append(TOS[-i], TOS)``. Used to implement list comprehensions.
|
||||
While the appended value is popped off, the list object remains on the
|
||||
stack so that it is available for further iterations of the loop.
|
||||
|
||||
|
||||
.. opcode:: LOAD_LOCALS ()
|
||||
|
|
|
|||
|
|
@ -22,7 +22,6 @@ extern "C" {
|
|||
|
||||
#define UNARY_INVERT 15
|
||||
|
||||
#define LIST_APPEND 18
|
||||
#define BINARY_POWER 19
|
||||
|
||||
#define BINARY_MULTIPLY 20
|
||||
|
|
@ -89,6 +88,7 @@ extern "C" {
|
|||
#define DELETE_NAME 91 /* "" */
|
||||
#define UNPACK_SEQUENCE 92 /* Number of sequence items */
|
||||
#define FOR_ITER 93
|
||||
#define LIST_APPEND 94
|
||||
|
||||
#define STORE_ATTR 95 /* Index in name list */
|
||||
#define DELETE_ATTR 96 /* "" */
|
||||
|
|
|
|||
|
|
@ -570,16 +570,10 @@ def visitCompare(self, node):
|
|||
self.nextBlock(end)
|
||||
|
||||
# list comprehensions
|
||||
__list_count = 0
|
||||
|
||||
def visitListComp(self, node):
|
||||
self.set_lineno(node)
|
||||
# setup list
|
||||
tmpname = "$list%d" % self.__list_count
|
||||
self.__list_count = self.__list_count + 1
|
||||
self.emit('BUILD_LIST', 0)
|
||||
self.emit('DUP_TOP')
|
||||
self._implicitNameOp('STORE', tmpname)
|
||||
|
||||
stack = []
|
||||
for i, for_ in zip(range(len(node.quals)), node.quals):
|
||||
|
|
@ -591,9 +585,8 @@ def visitListComp(self, node):
|
|||
self.visit(if_, cont)
|
||||
stack.insert(0, (start, cont, anchor))
|
||||
|
||||
self._implicitNameOp('LOAD', tmpname)
|
||||
self.visit(node.expr)
|
||||
self.emit('LIST_APPEND')
|
||||
self.emit('LIST_APPEND', len(node.quals) + 1)
|
||||
|
||||
for start, cont, anchor in stack:
|
||||
if cont:
|
||||
|
|
@ -604,9 +597,6 @@ def visitListComp(self, node):
|
|||
self.nextBlock(skip_one)
|
||||
self.emit('JUMP_ABSOLUTE', start)
|
||||
self.startBlock(anchor)
|
||||
self._implicitNameOp('DELETE', tmpname)
|
||||
|
||||
self.__list_count = self.__list_count - 1
|
||||
|
||||
def visitListCompFor(self, node):
|
||||
start = self.newBlock()
|
||||
|
|
|
|||
|
|
@ -58,7 +58,6 @@ def jabs_op(name, op):
|
|||
|
||||
def_op('UNARY_INVERT', 15)
|
||||
|
||||
def_op('LIST_APPEND', 18)
|
||||
def_op('BINARY_POWER', 19)
|
||||
def_op('BINARY_MULTIPLY', 20)
|
||||
def_op('BINARY_DIVIDE', 21)
|
||||
|
|
@ -128,7 +127,7 @@ def jabs_op(name, op):
|
|||
name_op('DELETE_NAME', 91) # ""
|
||||
def_op('UNPACK_SEQUENCE', 92) # Number of tuple items
|
||||
jrel_op('FOR_ITER', 93)
|
||||
|
||||
def_op('LIST_APPEND', 94)
|
||||
name_op('STORE_ATTR', 95) # Index in name list
|
||||
name_op('DELETE_ATTR', 96) # ""
|
||||
name_op('STORE_GLOBAL', 97) # ""
|
||||
|
|
|
|||
|
|
@ -54,29 +54,25 @@ def bug1333982(x=[]):
|
|||
|
||||
dis_bug1333982 = """\
|
||||
%-4d 0 LOAD_CONST 1 (0)
|
||||
3 JUMP_IF_TRUE 41 (to 47)
|
||||
3 JUMP_IF_TRUE 33 (to 39)
|
||||
6 POP_TOP
|
||||
7 LOAD_GLOBAL 0 (AssertionError)
|
||||
10 BUILD_LIST 0
|
||||
13 DUP_TOP
|
||||
14 STORE_FAST 1 (_[1])
|
||||
17 LOAD_FAST 0 (x)
|
||||
20 GET_ITER
|
||||
>> 21 FOR_ITER 13 (to 37)
|
||||
24 STORE_FAST 2 (s)
|
||||
27 LOAD_FAST 1 (_[1])
|
||||
30 LOAD_FAST 2 (s)
|
||||
33 LIST_APPEND
|
||||
34 JUMP_ABSOLUTE 21
|
||||
>> 37 DELETE_FAST 1 (_[1])
|
||||
13 LOAD_FAST 0 (x)
|
||||
16 GET_ITER
|
||||
>> 17 FOR_ITER 12 (to 32)
|
||||
20 STORE_FAST 1 (s)
|
||||
23 LOAD_FAST 1 (s)
|
||||
26 LIST_APPEND 2
|
||||
29 JUMP_ABSOLUTE 17
|
||||
|
||||
%-4d 40 LOAD_CONST 2 (1)
|
||||
43 BINARY_ADD
|
||||
44 RAISE_VARARGS 2
|
||||
>> 47 POP_TOP
|
||||
%-4d >> 32 LOAD_CONST 2 (1)
|
||||
35 BINARY_ADD
|
||||
36 RAISE_VARARGS 2
|
||||
>> 39 POP_TOP
|
||||
|
||||
%-4d 48 LOAD_CONST 0 (None)
|
||||
51 RETURN_VALUE
|
||||
%-4d 40 LOAD_CONST 0 (None)
|
||||
43 RETURN_VALUE
|
||||
"""%(bug1333982.func_code.co_firstlineno + 1,
|
||||
bug1333982.func_code.co_firstlineno + 2,
|
||||
bug1333982.func_code.co_firstlineno + 3)
|
||||
|
|
|
|||
|
|
@ -12,6 +12,9 @@ What's New in Python 2.7 alpha 1
|
|||
Core and Builtins
|
||||
-----------------
|
||||
|
||||
- Issue #2183: Simplify and optimize bytecode for list comprehensions.
|
||||
Original patch by Neal Norwitz.
|
||||
|
||||
- Issue #4597: Fixed exception handling when the __exit__ function of a
|
||||
context manager returns a value that cannot be converted to a bool.
|
||||
|
||||
|
|
|
|||
|
|
@ -1294,9 +1294,8 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throwflag)
|
|||
|
||||
case LIST_APPEND:
|
||||
w = POP();
|
||||
v = POP();
|
||||
v = stack_pointer[-oparg];
|
||||
err = PyList_Append(v, w);
|
||||
Py_DECREF(v);
|
||||
Py_DECREF(w);
|
||||
if (err == 0) {
|
||||
PREDICT(JUMP_ABSOLUTE);
|
||||
|
|
|
|||
|
|
@ -693,7 +693,7 @@ opcode_stack_effect(int opcode, int oparg)
|
|||
return 0;
|
||||
|
||||
case LIST_APPEND:
|
||||
return -2;
|
||||
return -1;
|
||||
|
||||
case BINARY_POWER:
|
||||
case BINARY_MULTIPLY:
|
||||
|
|
@ -2599,9 +2599,8 @@ compiler_call(struct compiler *c, expr_ty e)
|
|||
}
|
||||
|
||||
static int
|
||||
compiler_listcomp_generator(struct compiler *c, PyObject *tmpname,
|
||||
asdl_seq *generators, int gen_index,
|
||||
expr_ty elt)
|
||||
compiler_listcomp_generator(struct compiler *c, asdl_seq *generators,
|
||||
int gen_index, expr_ty elt)
|
||||
{
|
||||
/* generate code for the iterator, then each of the ifs,
|
||||
and then write to the element */
|
||||
|
|
@ -2638,16 +2637,13 @@ compiler_listcomp_generator(struct compiler *c, PyObject *tmpname,
|
|||
}
|
||||
|
||||
if (++gen_index < asdl_seq_LEN(generators))
|
||||
if (!compiler_listcomp_generator(c, tmpname,
|
||||
generators, gen_index, elt))
|
||||
if (!compiler_listcomp_generator(c, generators, gen_index, elt))
|
||||
return 0;
|
||||
|
||||
/* only append after the last for generator */
|
||||
if (gen_index >= asdl_seq_LEN(generators)) {
|
||||
if (!compiler_nameop(c, tmpname, Load))
|
||||
return 0;
|
||||
VISIT(c, expr, elt);
|
||||
ADDOP(c, LIST_APPEND);
|
||||
ADDOP_I(c, LIST_APPEND, gen_index+1);
|
||||
|
||||
compiler_use_next_block(c, skip);
|
||||
}
|
||||
|
|
@ -2659,10 +2655,6 @@ compiler_listcomp_generator(struct compiler *c, PyObject *tmpname,
|
|||
}
|
||||
ADDOP_JABS(c, JUMP_ABSOLUTE, start);
|
||||
compiler_use_next_block(c, anchor);
|
||||
/* delete the temporary list name added to locals */
|
||||
if (gen_index == 1)
|
||||
if (!compiler_nameop(c, tmpname, Del))
|
||||
return 0;
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
|
@ -2670,21 +2662,10 @@ compiler_listcomp_generator(struct compiler *c, PyObject *tmpname,
|
|||
static int
|
||||
compiler_listcomp(struct compiler *c, expr_ty e)
|
||||
{
|
||||
identifier tmp;
|
||||
int rc = 0;
|
||||
asdl_seq *generators = e->v.ListComp.generators;
|
||||
|
||||
assert(e->kind == ListComp_kind);
|
||||
tmp = compiler_new_tmpname(c);
|
||||
if (!tmp)
|
||||
return 0;
|
||||
ADDOP_I(c, BUILD_LIST, 0);
|
||||
ADDOP(c, DUP_TOP);
|
||||
if (compiler_nameop(c, tmp, Store))
|
||||
rc = compiler_listcomp_generator(c, tmp, generators, 0,
|
||||
return compiler_listcomp_generator(c, e->v.ListComp.generators, 0,
|
||||
e->v.ListComp.elt);
|
||||
Py_DECREF(tmp);
|
||||
return rc;
|
||||
}
|
||||
|
||||
static int
|
||||
|
|
|
|||
|
|
@ -73,9 +73,10 @@ extern time_t PyOS_GetLastModificationTime(char *, FILE *);
|
|||
Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)
|
||||
Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)
|
||||
Python 2.6a1: 62161 (WITH_CLEANUP optimization)
|
||||
Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND)
|
||||
.
|
||||
*/
|
||||
#define MAGIC (62161 | ((long)'\r'<<16) | ((long)'\n'<<24))
|
||||
#define MAGIC (62171 | ((long)'\r'<<16) | ((long)'\n'<<24))
|
||||
|
||||
/* Magic word as global; note that _PyImport_Init() can change the
|
||||
value of this global to accommodate for alterations of how the
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue