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bpo-27129: Use instruction offsets, not byte offsets, in bytecode and internally. (GH-25069)
* Use instruction offset, rather than bytecode offset. Streamlines interpreter dispatch a bit, and removes most EXTENDED_ARGs for jumps. * Change some uses of PyCode_Addr2Line to PyFrame_GetLineNumber
1 parent 2ac0515 commit fcb55c0

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14 files changed

+4561
-4562
lines changed

14 files changed

+4561
-4562
lines changed

‎Lib/dis.py‎

Lines changed: 6 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -338,8 +338,11 @@ def _get_instructions_bytes(code, varnames=None, names=None, constants=None,
338338
argval, argrepr = _get_const_info(arg, constants)
339339
elif op in hasname:
340340
argval, argrepr = _get_name_info(arg, names)
341+
elif op in hasjabs:
342+
argval = arg*2
343+
argrepr = "to " + repr(argval)
341344
elif op in hasjrel:
342-
argval = offset + 2 + arg
345+
argval = offset + 2 + arg*2
343346
argrepr = "to " + repr(argval)
344347
elif op in haslocal:
345348
argval, argrepr = _get_name_info(arg, varnames)
@@ -437,9 +440,9 @@ def findlabels(code):
437440
for offset, op, arg in _unpack_opargs(code):
438441
if arg is not None:
439442
if op in hasjrel:
440-
label = offset + 2 + arg
443+
label = offset + 2 + arg*2
441444
elif op in hasjabs:
442-
label = arg
445+
label = arg*2
443446
else:
444447
continue
445448
if label not in labels:

‎Lib/importlib/_bootstrap_external.py‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -314,6 +314,7 @@ def _write_atomic(path, data, mode=0o666):
314314
# Python 3.10a2 3432 (Function annotation for MAKE_FUNCTION is changed from dict to tuple bpo-42202)
315315
# Python 3.10a2 3433 (RERAISE restores f_lasti if oparg != 0)
316316
# Python 3.10a6 3434 (PEP 634: Structural Pattern Matching)
317+
# Python 3.10a7 3435 Use instruction offsets (as opposed to byte offsets).
317318

318319
#
319320
# MAGIC must change whenever the bytecode emitted by the compiler may no

‎Lib/test/test_dis.py‎

Lines changed: 30 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -127,10 +127,10 @@ def bug708901():
127127
128128
%3d 6 CALL_FUNCTION 2
129129
8 GET_ITER
130-
>> 10 FOR_ITER 4 (to 16)
130+
>> 10 FOR_ITER 2 (to 16)
131131
12 STORE_FAST 0 (res)
132132
133-
%3d 14 JUMP_ABSOLUTE 10
133+
%3d 14 JUMP_ABSOLUTE 5 (to 10)
134134
135135
%3d >> 16 LOAD_CONST 0 (None)
136136
18 RETURN_VALUE
@@ -276,11 +276,11 @@ def bug42562():
276276
10 INPLACE_ADD
277277
12 STORE_NAME 0 (x)
278278
279-
2 14 JUMP_ABSOLUTE 6
279+
2 14 JUMP_ABSOLUTE 3 (to 6)
280280
"""
281281

282282
dis_traceback = """\
283-
%3d 0 SETUP_FINALLY 14 (to 16)
283+
%3d 0 SETUP_FINALLY 7 (to 16)
284284
285285
%3d 2 LOAD_CONST 1 (1)
286286
4 LOAD_CONST 2 (0)
@@ -293,11 +293,11 @@ def bug42562():
293293
294294
%3d >> 16 DUP_TOP
295295
18 LOAD_GLOBAL 0 (Exception)
296-
20 JUMP_IF_NOT_EXC_MATCH 58
296+
20 JUMP_IF_NOT_EXC_MATCH 29 (to 58)
297297
22 POP_TOP
298298
24 STORE_FAST 0 (e)
299299
26 POP_TOP
300-
28 SETUP_FINALLY 20 (to 50)
300+
28 SETUP_FINALLY 10 (to 50)
301301
302302
%3d 30 LOAD_FAST 0 (e)
303303
32 LOAD_ATTR 1 (__traceback__)
@@ -358,7 +358,7 @@ def _tryfinallyconst(b):
358358
b()
359359

360360
dis_tryfinally = """\
361-
%3d 0 SETUP_FINALLY 12 (to 14)
361+
%3d 0 SETUP_FINALLY 6 (to 14)
362362
363363
%3d 2 LOAD_FAST 0 (a)
364364
4 POP_BLOCK
@@ -377,7 +377,7 @@ def _tryfinallyconst(b):
377377
)
378378

379379
dis_tryfinallyconst = """\
380-
%3d 0 SETUP_FINALLY 12 (to 14)
380+
%3d 0 SETUP_FINALLY 6 (to 14)
381381
382382
%3d 2 POP_BLOCK
383383
@@ -450,13 +450,13 @@ def foo(x):
450450
Disassembly of <code object <listcomp> at 0x..., file "%s", line %d>:
451451
%3d 0 BUILD_LIST 0
452452
2 LOAD_FAST 0 (.0)
453-
>> 4 FOR_ITER 12 (to 18)
453+
>> 4 FOR_ITER 6 (to 18)
454454
6 STORE_FAST 1 (z)
455455
8 LOAD_DEREF 0 (x)
456456
10 LOAD_FAST 1 (z)
457457
12 BINARY_ADD
458458
14 LIST_APPEND 2
459-
16 JUMP_ABSOLUTE 4
459+
16 JUMP_ABSOLUTE 2 (to 4)
460460
>> 18 RETURN_VALUE
461461
""" % (dis_nested_1,
462462
__file__,
@@ -1009,7 +1009,7 @@ def jumpy():
10091009
Instruction(opname='LOAD_CONST', opcode=100, arg=1, argval=10, argrepr='10', offset=2, starts_line=None, is_jump_target=False),
10101010
Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=4, starts_line=None, is_jump_target=False),
10111011
Instruction(opname='GET_ITER', opcode=68, arg=None, argval=None, argrepr='', offset=6, starts_line=None, is_jump_target=False),
1012-
Instruction(opname='FOR_ITER', opcode=93, arg=34, argval=44, argrepr='to 44', offset=8, starts_line=None, is_jump_target=True),
1012+
Instruction(opname='FOR_ITER', opcode=93, arg=17, argval=44, argrepr='to 44', offset=8, starts_line=None, is_jump_target=True),
10131013
Instruction(opname='STORE_FAST', opcode=125, arg=0, argval='i', argrepr='i', offset=10, starts_line=None, is_jump_target=False),
10141014
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=12, starts_line=4, is_jump_target=False),
10151015
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=14, starts_line=None, is_jump_target=False),
@@ -1018,21 +1018,21 @@ def jumpy():
10181018
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=20, starts_line=5, is_jump_target=False),
10191019
Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=22, starts_line=None, is_jump_target=False),
10201020
Instruction(opname='COMPARE_OP', opcode=107, arg=0, argval='<', argrepr='<', offset=24, starts_line=None, is_jump_target=False),
1021-
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=30, argval=30, argrepr='', offset=26, starts_line=None, is_jump_target=False),
1022-
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=8, argval=8, argrepr='', offset=28, starts_line=6, is_jump_target=False),
1021+
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=15, argval=30, argrepr='to 30', offset=26, starts_line=None, is_jump_target=False),
1022+
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=4, argval=8, argrepr='to 8', offset=28, starts_line=6, is_jump_target=False),
10231023
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=30, starts_line=7, is_jump_target=True),
10241024
Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=32, starts_line=None, is_jump_target=False),
10251025
Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=34, starts_line=None, is_jump_target=False),
1026-
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=42, argval=42, argrepr='', offset=36, starts_line=None, is_jump_target=False),
1026+
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=21, argval=42, argrepr='to 42', offset=36, starts_line=None, is_jump_target=False),
10271027
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=38, starts_line=8, is_jump_target=False),
1028-
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=52, argval=52, argrepr='', offset=40, starts_line=None, is_jump_target=False),
1029-
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=8, argval=8, argrepr='', offset=42, starts_line=7, is_jump_target=True),
1028+
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=26, argval=52, argrepr='to 52', offset=40, starts_line=None, is_jump_target=False),
1029+
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=4, argval=8, argrepr='to 8', offset=42, starts_line=7, is_jump_target=True),
10301030
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=44, starts_line=10, is_jump_target=True),
10311031
Instruction(opname='LOAD_CONST', opcode=100, arg=4, argval='I can haz else clause?', argrepr="'I can haz else clause?'", offset=46, starts_line=None, is_jump_target=False),
10321032
Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=48, starts_line=None, is_jump_target=False),
10331033
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=50, starts_line=None, is_jump_target=False),
10341034
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=52, starts_line=11, is_jump_target=True),
1035-
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=96, argval=96, argrepr='', offset=54, starts_line=None, is_jump_target=False),
1035+
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=48, argval=96, argrepr='to 96', offset=54, starts_line=None, is_jump_target=False),
10361036
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=56, starts_line=12, is_jump_target=True),
10371037
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=58, starts_line=None, is_jump_target=False),
10381038
Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=60, starts_line=None, is_jump_target=False),
@@ -1044,30 +1044,30 @@ def jumpy():
10441044
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=72, starts_line=14, is_jump_target=False),
10451045
Instruction(opname='LOAD_CONST', opcode=100, arg=3, argval=6, argrepr='6', offset=74, starts_line=None, is_jump_target=False),
10461046
Instruction(opname='COMPARE_OP', opcode=107, arg=4, argval='>', argrepr='>', offset=76, starts_line=None, is_jump_target=False),
1047-
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=82, argval=82, argrepr='', offset=78, starts_line=None, is_jump_target=False),
1048-
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=52, argval=52, argrepr='', offset=80, starts_line=15, is_jump_target=False),
1047+
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=41, argval=82, argrepr='to 82', offset=78, starts_line=None, is_jump_target=False),
1048+
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=26, argval=52, argrepr='to 52', offset=80, starts_line=15, is_jump_target=False),
10491049
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=82, starts_line=16, is_jump_target=True),
10501050
Instruction(opname='LOAD_CONST', opcode=100, arg=2, argval=4, argrepr='4', offset=84, starts_line=None, is_jump_target=False),
10511051
Instruction(opname='COMPARE_OP', opcode=107, arg=0, argval='<', argrepr='<', offset=86, starts_line=None, is_jump_target=False),
1052-
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=92, argval=92, argrepr='', offset=88, starts_line=None, is_jump_target=False),
1053-
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=104, argval=104, argrepr='', offset=90, starts_line=17, is_jump_target=False),
1052+
Instruction(opname='POP_JUMP_IF_FALSE', opcode=114, arg=46, argval=92, argrepr='to 92', offset=88, starts_line=None, is_jump_target=False),
1053+
Instruction(opname='JUMP_ABSOLUTE', opcode=113, arg=52, argval=104, argrepr='to 104', offset=90, starts_line=17, is_jump_target=False),
10541054
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=92, starts_line=11, is_jump_target=True),
1055-
Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=56, argval=56, argrepr='', offset=94, starts_line=None, is_jump_target=False),
1055+
Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=28, argval=56, argrepr='to 56', offset=94, starts_line=None, is_jump_target=False),
10561056
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=96, starts_line=19, is_jump_target=True),
10571057
Instruction(opname='LOAD_CONST', opcode=100, arg=6, argval='Who let lolcatz into this test suite?', argrepr="'Who let lolcatz into this test suite?'", offset=98, starts_line=None, is_jump_target=False),
10581058
Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=100, starts_line=None, is_jump_target=False),
10591059
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=102, starts_line=None, is_jump_target=False),
1060-
Instruction(opname='SETUP_FINALLY', opcode=122, arg=96, argval=202, argrepr='to 202', offset=104, starts_line=20, is_jump_target=True),
1061-
Instruction(opname='SETUP_FINALLY', opcode=122, arg=12, argval=120, argrepr='to 120', offset=106, starts_line=None, is_jump_target=False),
1060+
Instruction(opname='SETUP_FINALLY', opcode=122, arg=48, argval=202, argrepr='to 202', offset=104, starts_line=20, is_jump_target=True),
1061+
Instruction(opname='SETUP_FINALLY', opcode=122, arg=6, argval=120, argrepr='to 120', offset=106, starts_line=None, is_jump_target=False),
10621062
Instruction(opname='LOAD_CONST', opcode=100, arg=5, argval=1, argrepr='1', offset=108, starts_line=21, is_jump_target=False),
10631063
Instruction(opname='LOAD_CONST', opcode=100, arg=7, argval=0, argrepr='0', offset=110, starts_line=None, is_jump_target=False),
10641064
Instruction(opname='BINARY_TRUE_DIVIDE', opcode=27, arg=None, argval=None, argrepr='', offset=112, starts_line=None, is_jump_target=False),
10651065
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=114, starts_line=None, is_jump_target=False),
10661066
Instruction(opname='POP_BLOCK', opcode=87, arg=None, argval=None, argrepr='', offset=116, starts_line=None, is_jump_target=False),
1067-
Instruction(opname='JUMP_FORWARD', opcode=110, arg=24, argval=144, argrepr='to 144', offset=118, starts_line=None, is_jump_target=False),
1067+
Instruction(opname='JUMP_FORWARD', opcode=110, arg=12, argval=144, argrepr='to 144', offset=118, starts_line=None, is_jump_target=False),
10681068
Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=120, starts_line=22, is_jump_target=True),
10691069
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=2, argval='ZeroDivisionError', argrepr='ZeroDivisionError', offset=122, starts_line=None, is_jump_target=False),
1070-
Instruction(opname='JUMP_IF_NOT_EXC_MATCH', opcode=121, arg=212, argval=212, argrepr='', offset=124, starts_line=None, is_jump_target=False),
1070+
Instruction(opname='JUMP_IF_NOT_EXC_MATCH', opcode=121, arg=106, argval=212, argrepr='to 212', offset=124, starts_line=None, is_jump_target=False),
10711071
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=126, starts_line=None, is_jump_target=False),
10721072
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=128, starts_line=None, is_jump_target=False),
10731073
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=130, starts_line=None, is_jump_target=False),
@@ -1076,9 +1076,9 @@ def jumpy():
10761076
Instruction(opname='CALL_FUNCTION', opcode=131, arg=1, argval=1, argrepr='', offset=136, starts_line=None, is_jump_target=False),
10771077
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=138, starts_line=None, is_jump_target=False),
10781078
Instruction(opname='POP_EXCEPT', opcode=89, arg=None, argval=None, argrepr='', offset=140, starts_line=None, is_jump_target=False),
1079-
Instruction(opname='JUMP_FORWARD', opcode=110, arg=44, argval=188, argrepr='to 188', offset=142, starts_line=None, is_jump_target=False),
1079+
Instruction(opname='JUMP_FORWARD', opcode=110, arg=22, argval=188, argrepr='to 188', offset=142, starts_line=None, is_jump_target=False),
10801080
Instruction(opname='LOAD_FAST', opcode=124, arg=0, argval='i', argrepr='i', offset=144, starts_line=25, is_jump_target=True),
1081-
Instruction(opname='SETUP_WITH', opcode=143, arg=24, argval=172, argrepr='to 172', offset=146, starts_line=None, is_jump_target=False),
1081+
Instruction(opname='SETUP_WITH', opcode=143, arg=12, argval=172, argrepr='to 172', offset=146, starts_line=None, is_jump_target=False),
10821082
Instruction(opname='STORE_FAST', opcode=125, arg=1, argval='dodgy', argrepr='dodgy', offset=148, starts_line=None, is_jump_target=False),
10831083
Instruction(opname='LOAD_GLOBAL', opcode=116, arg=1, argval='print', argrepr='print', offset=150, starts_line=26, is_jump_target=False),
10841084
Instruction(opname='LOAD_CONST', opcode=100, arg=9, argval='Never reach this', argrepr="'Never reach this'", offset=152, starts_line=None, is_jump_target=False),
@@ -1090,9 +1090,9 @@ def jumpy():
10901090
Instruction(opname='DUP_TOP', opcode=4, arg=None, argval=None, argrepr='', offset=164, starts_line=None, is_jump_target=False),
10911091
Instruction(opname='CALL_FUNCTION', opcode=131, arg=3, argval=3, argrepr='', offset=166, starts_line=None, is_jump_target=False),
10921092
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=168, starts_line=None, is_jump_target=False),
1093-
Instruction(opname='JUMP_FORWARD', opcode=110, arg=16, argval=188, argrepr='to 188', offset=170, starts_line=None, is_jump_target=False),
1093+
Instruction(opname='JUMP_FORWARD', opcode=110, arg=8, argval=188, argrepr='to 188', offset=170, starts_line=None, is_jump_target=False),
10941094
Instruction(opname='WITH_EXCEPT_START', opcode=49, arg=None, argval=None, argrepr='', offset=172, starts_line=None, is_jump_target=True),
1095-
Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=178, argval=178, argrepr='', offset=174, starts_line=None, is_jump_target=False),
1095+
Instruction(opname='POP_JUMP_IF_TRUE', opcode=115, arg=89, argval=178, argrepr='to 178', offset=174, starts_line=None, is_jump_target=False),
10961096
Instruction(opname='RERAISE', opcode=119, arg=1, argval=1, argrepr='', offset=176, starts_line=None, is_jump_target=False),
10971097
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=178, starts_line=None, is_jump_target=True),
10981098
Instruction(opname='POP_TOP', opcode=1, arg=None, argval=None, argrepr='', offset=180, starts_line=None, is_jump_target=False),

‎Misc/NEWS.d/next/Core and Builtins/2021-03-29-16-20-29.bpo-27129.BF03A5.rst‎

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,3 @@
1+
The bytecode interpreter uses instruction, rather byte, offsets internally.
2+
This reduces the number of EXTENDED_ARG instructions needed and streamlines
3+
instruction dispatch a bit.

‎Objects/codeobject.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1246,7 +1246,7 @@ PyTypeObject PyCode_Type = {
12461246
int
12471247
PyCode_Addr2Line(PyCodeObject *co, int addrq)
12481248
{
1249-
if (addrq == -1) {
1249+
if (addrq < 0) {
12501250
return co->co_firstlineno;
12511251
}
12521252
assert(addrq >= 0 && addrq < PyBytes_GET_SIZE(co->co_code));

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