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gh-126835: Move const folding of lists & sets from ast_opt.c to flowgraph.c (#130032)

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Yan Yanchii 2025-02-13 13:11:07 +01:00 • committed by GitHub
parent c7a9d06e06
commit 140e69c4a8
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5 changed files with 231 additions and 120 deletions
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52
Python/flowgraph.c
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@ -1428,31 +1428,41 @@ fold_tuple_of_constants(basicblock *bb, int n, PyObject *consts, PyObject *const
}
#define MIN_CONST_SEQUENCE_SIZE 3
/* Replace LOAD_CONST c1, LOAD_CONST c2 ... LOAD_CONST cN, BUILD_LIST N
with BUILD_LIST 0, LOAD_CONST (c1, c2, ... cN), LIST_EXTEND 1,
or BUILD_SET & SET_UPDATE respectively.
/*
Optimize lists and sets for:
1. "for" loop, comprehension or "in"/"not in" tests:
Change literal list or set of constants into constant
tuple or frozenset respectively. Change list of
non-constants into tuple.
2. Constant literal lists/set with length >= MIN_CONST_SEQUENCE_SIZE:
Replace LOAD_CONST c1, LOAD_CONST c2 ... LOAD_CONST cN, BUILD_LIST N
with BUILD_LIST 0, LOAD_CONST (c1, c2, ... cN), LIST_EXTEND 1,
or BUILD_SET & SET_UPDATE respectively.
*/
static int
optimize_if_const_list_or_set(basicblock *bb, int n, PyObject *consts, PyObject *const_cache)
optimize_lists_and_sets(basicblock *bb, int i, int nextop,
PyObject *consts, PyObject *const_cache)
{
assert(PyDict_CheckExact(const_cache));
assert(PyList_CheckExact(consts));
cfg_instr *instr = &bb->b_instr[n];
cfg_instr *instr = &bb->b_instr[i];
assert(instr->i_opcode == BUILD_LIST || instr->i_opcode == BUILD_SET);
bool contains_or_iter = nextop == GET_ITER || nextop == CONTAINS_OP;
int seq_size = instr->i_oparg;
if (seq_size < MIN_CONST_SEQUENCE_SIZE) {
if (seq_size < MIN_CONST_SEQUENCE_SIZE && !contains_or_iter) {
return SUCCESS;
}
PyObject *newconst;
RETURN_IF_ERROR(get_constant_sequence(bb, n-1, seq_size, consts, &newconst));
if (newconst == NULL) {
/* not a const sequence */
RETURN_IF_ERROR(get_constant_sequence(bb, i-1, seq_size, consts, &newconst));
if (newconst == NULL) { /* not a const sequence */
if (contains_or_iter && instr->i_opcode == BUILD_LIST) {
/* iterate over a tuple instead of list */
INSTR_SET_OP1(instr, BUILD_TUPLE, instr->i_oparg);
}
return SUCCESS;
}
assert(PyTuple_CheckExact(newconst) && PyTuple_GET_SIZE(newconst) == seq_size);
int build = instr->i_opcode;
int extend = build == BUILD_LIST ? LIST_EXTEND : SET_UPDATE;
if (build == BUILD_SET) {
if (instr->i_opcode == BUILD_SET) {
PyObject *frozenset = PyFrozenSet_New(newconst);
if (frozenset == NULL) {
Py_DECREF(newconst);
@ -1462,11 +1472,17 @@ optimize_if_const_list_or_set(basicblock *bb, int n, PyObject *consts, PyObject
}
int index = add_const(newconst, consts, const_cache);
RETURN_IF_ERROR(index);
nop_out(bb, n-1, seq_size);
assert(n >= 2);
INSTR_SET_OP1(&bb->b_instr[n-2], build, 0);
INSTR_SET_OP1(&bb->b_instr[n-1], LOAD_CONST, index);
INSTR_SET_OP1(&bb->b_instr[n], extend, 1);
nop_out(bb, i-1, seq_size);
if (contains_or_iter) {
INSTR_SET_OP1(instr, LOAD_CONST, index);
}
else {
assert(i >= 2);
assert(instr->i_opcode == BUILD_LIST || instr->i_opcode == BUILD_SET);
INSTR_SET_OP1(&bb->b_instr[i-2], instr->i_opcode, 0);
INSTR_SET_OP1(&bb->b_instr[i-1], LOAD_CONST, index);
INSTR_SET_OP1(&bb->b_instr[i], instr->i_opcode == BUILD_LIST ? LIST_EXTEND : SET_UPDATE, 1);
}
return SUCCESS;
}
@ -1923,7 +1939,7 @@ optimize_basic_block(PyObject *const_cache, basicblock *bb, PyObject *consts)
break;
case BUILD_LIST:
case BUILD_SET:
RETURN_IF_ERROR(optimize_if_const_list_or_set(bb, i, consts, const_cache));
RETURN_IF_ERROR(optimize_lists_and_sets(bb, i, nextop, consts, const_cache));
break;
case POP_JUMP_IF_NOT_NONE:
case POP_JUMP_IF_NONE: