Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

GH-100982: Add COMPARE_AND_BRANCH instruction #100983

Merged
merged 10 commits into from
Jan 16, 2023
Merged

GH-100982: Add COMPARE_AND_BRANCH instruction #100983

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
e5059b2
Add COMPARE_AND_BRANCH instruction
markshannon Jan 11, 2023
482777c
Update summarize stats script to handle both COMPAREs.
markshannon Jan 11, 2023
358393d
Remove attempted specialization of COMPARE_OP.
markshannon Jan 12, 2023
c5c1764
Add news
markshannon Jan 12, 2023
944147c
Document COMPARE_OP instruction.
markshannon Jan 12, 2023
ef3fe45
Document the correct instruction
markshannon Jan 12, 2023
447f63e
Regenerate file
markshannon Jan 12, 2023
7d33508
Revert change to COMPARE_AND_BRANCH classification.
markshannon Jan 12, 2023
776ba54
Avoid unused variable warning when NDEBUG is defined.
markshannon Jan 16, 2023
5b01cc5
Merge branch 'main' into compare-and-branch-instruction-2
markshannon Jan 16, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 9 additions & 0 deletions Doc/library/dis.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1043,6 +1043,15 @@ iterations of the loop.
``cmp_op[opname]``.


.. opcode:: COMPARE_AND_BRANCH (opname)

Compares the top two values on the stack, popping them, then branches.
The direction and offset of the jump is embedded as a ``POP_JUMP_IF_TRUE``
or ``POP_JUMP_IF_FALSE`` instruction immediately following the cache.

.. versionadded:: 3.12


.. opcode:: IS_OP (invert)

Performs ``is`` comparison, or ``is not`` if ``invert`` is 1.
Expand Down
2 changes: 1 addition & 1 deletion Include/internal/pycore_code.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -228,7 +228,7 @@ extern void _Py_Specialize_Call(PyObject *callable, _Py_CODEUNIT *instr,
int nargs, PyObject *kwnames);
extern void _Py_Specialize_BinaryOp(PyObject *lhs, PyObject *rhs, _Py_CODEUNIT *instr,
int oparg, PyObject **locals);
extern void _Py_Specialize_CompareOp(PyObject *lhs, PyObject *rhs,
extern void _Py_Specialize_CompareAndBranch(PyObject *lhs, PyObject *rhs,
_Py_CODEUNIT *instr, int oparg);
extern void _Py_Specialize_UnpackSequence(PyObject *seq, _Py_CODEUNIT *instr,
int oparg);
Expand Down
23 changes: 12 additions & 11 deletions Include/internal/pycore_opcode.h
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

19 changes: 10 additions & 9 deletions Include/opcode.h
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

3 changes: 2 additions & 1 deletion Lib/importlib/_bootstrap_external.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -429,6 +429,7 @@ def _write_atomic(path, data, mode=0o666):
# Python 3.12a1 3513 (Add CALL_INTRINSIC_1 instruction, removed STOPITERATION_ERROR, PRINT_EXPR, IMPORT_STAR)
# Python 3.12a1 3514 (Remove ASYNC_GEN_WRAP, LIST_TO_TUPLE, and UNARY_POSITIVE)
# Python 3.12a1 3515 (Embed jump mask in COMPARE_OP oparg)
# Python 3.12a1 3516 (Add COMAPRE_AND_BRANCH instruction)

# Python 3.13 will start with 3550

Expand All @@ -441,7 +442,7 @@ def _write_atomic(path, data, mode=0o666):
# Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array
# in PC/launcher.c must also be updated.

MAGIC_NUMBER = (3515).to_bytes(2, 'little') + b'\r\n'
MAGIC_NUMBER = (3516).to_bytes(2, 'little') + b'\r\n'
iritkatriel marked this conversation as resolved.
Show resolved Hide resolved

_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c

Expand Down
13 changes: 9 additions & 4 deletions Lib/opcode.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -189,6 +189,8 @@ def pseudo_op(name, op, real_ops):
def_op('DELETE_DEREF', 139)
hasfree.append(139)
jrel_op('JUMP_BACKWARD', 140) # Number of words to skip (backwards)
def_op('COMPARE_AND_BRANCH', 141) # Comparison and jump
hascompare.append(141)
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This opcode needs to be in hasjrel as well.

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The problem is that dis sees COMPARE_AND_BRANCH, then POP_JUMP_IF_. The POP_JUMP_IF_ is where we jump from.
So marking COMPARE_AND_BRANCH as a jump confuses dis, it thinks the operator is a jump offset. COMPARE_AND_BRANCH is effectively a superinstruction.

I could special case COMPARE_AND_BRANCH in dis, but I think it might be better to wait for proper support for longer instructions.


def_op('CALL_FUNCTION_EX', 142) # Flags

Expand Down Expand Up @@ -309,10 +311,10 @@ def pseudo_op(name, op, real_ops):
"CALL_NO_KW_TUPLE_1",
"CALL_NO_KW_TYPE_1",
],
"COMPARE_OP": [
"COMPARE_OP_FLOAT_JUMP",
"COMPARE_OP_INT_JUMP",
"COMPARE_OP_STR_JUMP",
"COMPARE_AND_BRANCH": [
"COMPARE_AND_BRANCH_FLOAT",
"COMPARE_AND_BRANCH_INT",
"COMPARE_AND_BRANCH_STR",
],
"FOR_ITER": [
"FOR_ITER_LIST",
Expand Down Expand Up @@ -392,6 +394,9 @@ def pseudo_op(name, op, real_ops):
"COMPARE_OP": {
"counter": 1,
},
"COMPARE_AND_BRANCH": {
"counter": 1,
},
"BINARY_SUBSCR": {
"counter": 1,
"type_version": 2,
Expand Down
14 changes: 7 additions & 7 deletions Lib/test/test_compile.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1121,11 +1121,11 @@ def aug():
check_op_count(aug, "BUILD_SLICE", 0)

def test_compare_positions(self):
for opname, op in [
("COMPARE_OP", "<"),
("COMPARE_OP", "<="),
("COMPARE_OP", ">"),
("COMPARE_OP", ">="),
for opname_prefix, op in [
("COMPARE_", "<"),
("COMPARE_", "<="),
("COMPARE_", ">"),
("COMPARE_", ">="),
("CONTAINS_OP", "in"),
("CONTAINS_OP", "not in"),
("IS_OP", "is"),
Expand All @@ -1140,7 +1140,7 @@ def test_compare_positions(self):
actual_positions = [
instruction.positions
for instruction in dis.get_instructions(code)
if instruction.opname == opname
if instruction.opname.startswith(opname_prefix)
]
with self.subTest(source):
self.assertEqual(actual_positions, expected_positions)
Expand Down Expand Up @@ -1270,7 +1270,7 @@ def test_multiline_boolean_expression(self):
self.assertOpcodeSourcePositionIs(compiled_code, 'POP_JUMP_IF_FALSE',
line=2, end_line=2, column=15, end_column=16, occurrence=2)
# compare d and 0
self.assertOpcodeSourcePositionIs(compiled_code, 'COMPARE_OP',
self.assertOpcodeSourcePositionIs(compiled_code, 'COMPARE_AND_BRANCH',
line=4, end_line=4, column=8, end_column=13, occurrence=1)
# jump if comparison it True
self.assertOpcodeSourcePositionIs(compiled_code, 'POP_JUMP_IF_TRUE',
Expand Down
8 changes: 4 additions & 4 deletions Lib/test/test_dis.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1561,12 +1561,12 @@ def _prepare_test_cases():
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=58, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=60, starts_line=5, is_jump_target=False, positions=None),
Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=62, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_OP', opcode=107, arg=13, argval='<', argrepr='<', offset=64, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_AND_BRANCH', opcode=141, arg=13, argval='<', argrepr='<', offset=64, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=72, argrepr='to 72', offset=68, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_BACKWARD', opcode=140, arg=22, argval=28, argrepr='to 28', offset=70, starts_line=6, is_jump_target=False, positions=None),
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=72, starts_line=7, is_jump_target=True, positions=None),
Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=74, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_OP', opcode=107, arg=68, argval='>', argrepr='>', offset=76, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_AND_BRANCH', opcode=141, arg=68, argval='>', argrepr='>', offset=76, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=1, argval=84, argrepr='to 84', offset=80, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_BACKWARD', opcode=140, arg=28, argval=28, argrepr='to 28', offset=82, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=84, starts_line=8, is_jump_target=True, positions=None),
Expand All @@ -1588,12 +1588,12 @@ def _prepare_test_cases():
Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=154, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=156, starts_line=14, is_jump_target=False, positions=None),
Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=158, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_OP', opcode=107, arg=75, argval='>', argrepr='>', offset=160, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_AND_BRANCH', opcode=141, arg=75, argval='>', argrepr='>', offset=160, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=168, argrepr='to 168', offset=164, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_BACKWARD', opcode=140, arg=26, argval=116, argrepr='to 116', offset=166, starts_line=15, is_jump_target=False, positions=None),
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=168, starts_line=16, is_jump_target=True, positions=None),
Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=170, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_OP', opcode=107, arg=13, argval='<', argrepr='<', offset=172, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='COMPARE_AND_BRANCH', opcode=141, arg=13, argval='<', argrepr='<', offset=172, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=1, argval=180, argrepr='to 180', offset=176, starts_line=None, is_jump_target=False, positions=None),
Instruction(opname='JUMP_FORWARD', opcode=110, arg=16, argval=212, argrepr='to 212', offset=178, starts_line=17, is_jump_target=False, positions=None),
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=180, starts_line=11, is_jump_target=True, positions=None),
Expand Down
4 changes: 4 additions & 0 deletions Misc/NEWS.d/next/Core and Builtins/2023-01-12-13-46-49.gh-issue-100982.mJ234s.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
Adds a new :opcode:`COMPARE_AND_BRANCH` instruction. This is a bit more
efficient when performing a comparison immediately followed by a branch, and
restores the design intent of PEP 659 that specializations are local to a
single instruction.
8 changes: 8 additions & 0 deletions Objects/frameobject.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -357,6 +357,14 @@ mark_stacks(PyCodeObject *code_obj, int len)
assert(stacks[j] == UNINITIALIZED || stacks[j] == next_stack);
stacks[j] = next_stack;
break;
case COMPARE_AND_BRANCH:
next_stack = pop_value(pop_value(next_stack));
i++;
j = get_arg(code, i) + i + 1;
assert(j < len);
assert(stacks[j] == UNINITIALIZED || stacks[j] == next_stack);
stacks[j] = next_stack;
break;
case GET_ITER:
case GET_AITER:
next_stack = push_value(pop_value(next_stack), Iterator);
Expand Down
Loading