gh-115178: Add Counts of UOp Pairs to pystats

[JeffersGlass]

Adds the ability to track pairs, triples, and longer sequences of UOps to the pystats statistics.

Currently, this only counts these statistics for the non-JIT tier 2 interpreter. I intend to include tracking in the JIT in a follow-up PR.

To try it out, run:

./configure --enable-pystats
./make
mkdir /tmp/py_stats
PYTHON_UOPS=1 ./python -X pystats -c $'x = 0\nfor i in range(1000):\n x+=i'

The output file at /tmp/py_stats/???.txt will contain a new section with UOp Sequence counts:

UOp sequence count[BUILD_TUPLE,_CHECK_VALIDITY]: 2
UOp sequence count[LIST_APPEND,_CHECK_VALIDITY]: 13
UOp sequence count[LOAD_DEREF,_SET_IP]: 2
UOp sequence count[LOAD_FAST,LOAD_FAST]: 7
...

Tools/scripts/summarize_stats.py has also been expanded to encompass these new stats, with a new section:

Counts for top 100 UOp Sequences of Length 2

Sequence	Count	Self	Cumulative
_CHECK_VALIDITY,_SET_IP	3,932	19.0%	19.0%
LOAD_NAME,_CHECK_VALIDITY	1,966	9.5%	28.6%
_SET_IP,LOAD_NAME	1,966	9.5%	38.1%
_ITER_CHECK_RANGE,_SET_IP	984	4.8%	42.9%
_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE	984	4.8%	47.6%
STORE_NAME,_SET_IP	983	4.8%	52.4%
STORE_NAME,_CHECK_VALIDITY	983	4.8%	57.1%
_SET_IP,STORE_NAME	983	4.8%	61.9%
_SET_IP,_BINARY_OP_ADD_INT	983	4.8%	66.7%
_SET_IP,_ITER_NEXT_RANGE	983	4.8%	71.4%
_SET_IP,_JUMP_TO_TOP	983	4.8%	76.2%
_GUARD_BOTH_INT,_CHECK_VALIDITY	983	4.8%	81.0%
_BINARY_OP_ADD_INT,_GUARD_BOTH_INT	983	4.8%	85.7%
_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE	983	4.8%	90.5%
_JUMP_TO_TOP,_CHECK_VALIDITY	983	4.8%	95.2%
_CHECK_VALIDITY,STORE_NAME	983	4.8%	100.0%

Finally, a new environment variable, PYTHONSTATS_UOPDEPTH can be set to any integer to record sequences of length longer than two. For example:

PYTHONSTATS_UOPDEPTH=4 PYTHON_UOPS=1 ./python -X pystats -c 'x = 0; for i in range(1000): x+=i

Yields:

Counts for top 100 UOp Sequences of Length 2

Sequence	Count	Self	Cumulative
_CHECK_VALIDITY,_SET_IP	3,932	19.0%	19.0%
LOAD_NAME,_CHECK_VALIDITY	1,966	9.5%	28.6%
_SET_IP,LOAD_NAME	1,966	9.5%	38.1%
_ITER_CHECK_RANGE,_SET_IP	984	4.8%	42.9%
_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE	984	4.8%	47.6%
STORE_NAME,_SET_IP	983	4.8%	52.4%
STORE_NAME,_CHECK_VALIDITY	983	4.8%	57.1%
_SET_IP,STORE_NAME	983	4.8%	61.9%
_SET_IP,_BINARY_OP_ADD_INT	983	4.8%	66.7%
_SET_IP,_ITER_NEXT_RANGE	983	4.8%	71.4%
_SET_IP,_JUMP_TO_TOP	983	4.8%	76.2%
_GUARD_BOTH_INT,_CHECK_VALIDITY	983	4.8%	81.0%
_BINARY_OP_ADD_INT,_GUARD_BOTH_INT	983	4.8%	85.7%
_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE	983	4.8%	90.5%
_JUMP_TO_TOP,_CHECK_VALIDITY	983	4.8%	95.2%
_CHECK_VALIDITY,STORE_NAME	983	4.8%	100.0%

Counts for top 100 UOp Sequences of Length 3

Sequence	Count	Self	Cumulative
LOAD_NAME,_CHECK_VALIDITY,_SET_IP	1,966	9.5%	9.5%
_SET_IP,LOAD_NAME,_CHECK_VALIDITY	1,966	9.5%	19.0%
_CHECK_VALIDITY,_SET_IP,LOAD_NAME	1,966	9.5%	28.6%
_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE,_SET_IP	984	4.8%	33.3%
STORE_NAME,_SET_IP,_BINARY_OP_ADD_INT	983	4.8%	38.1%
STORE_NAME,_CHECK_VALIDITY,_SET_IP	983	4.8%	42.9%
_SET_IP,STORE_NAME,_CHECK_VALIDITY	983	4.8%	47.6%
_SET_IP,_BINARY_OP_ADD_INT,_GUARD_BOTH_INT	983	4.8%	52.4%
_SET_IP,_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE	983	4.8%	57.1%
_SET_IP,_JUMP_TO_TOP,_CHECK_VALIDITY	983	4.8%	61.9%
_GUARD_BOTH_INT,_CHECK_VALIDITY,_SET_IP	983	4.8%	66.7%
_BINARY_OP_ADD_INT,_GUARD_BOTH_INT,_CHECK_VALIDITY	983	4.8%	71.4%
_ITER_CHECK_RANGE,_SET_IP,_JUMP_TO_TOP	983	4.8%	76.2%
_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE	983	4.8%	80.9%
_JUMP_TO_TOP,_CHECK_VALIDITY,STORE_NAME	983	4.8%	85.7%
_CHECK_VALIDITY,STORE_NAME,_SET_IP	983	4.8%	90.5%
_CHECK_VALIDITY,_SET_IP,STORE_NAME	983	4.8%	95.2%
_CHECK_VALIDITY,_SET_IP,_ITER_NEXT_RANGE	983	4.8%	100.0%

Counts for top 100 UOp Sequences of Length 4

Sequence	Count	Self	Cumulative
_SET_IP,LOAD_NAME,_CHECK_VALIDITY,_SET_IP	1,966	9.5%	9.5%
_CHECK_VALIDITY,_SET_IP,LOAD_NAME,_CHECK_VALIDITY	1,966	9.5%	19.0%
LOAD_NAME,_CHECK_VALIDITY,_SET_IP,LOAD_NAME	983	4.8%	23.8%
LOAD_NAME,_CHECK_VALIDITY,_SET_IP,STORE_NAME	983	4.8%	28.6%
STORE_NAME,_SET_IP,_BINARY_OP_ADD_INT,_GUARD_BOTH_INT	983	4.8%	33.3%
STORE_NAME,_CHECK_VALIDITY,_SET_IP,_ITER_NEXT_RANGE	983	4.8%	38.1%
_SET_IP,STORE_NAME,_CHECK_VALIDITY,_SET_IP	983	4.8%	42.9%
_SET_IP,_BINARY_OP_ADD_INT,_GUARD_BOTH_INT,_CHECK_VALIDITY	983	4.8%	47.6%
_SET_IP,_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE	983	4.8%	52.4%
_SET_IP,_JUMP_TO_TOP,_CHECK_VALIDITY,STORE_NAME	983	4.8%	57.1%
_GUARD_BOTH_INT,_CHECK_VALIDITY,_SET_IP,LOAD_NAME	983	4.8%	61.9%
_BINARY_OP_ADD_INT,_GUARD_BOTH_INT,_CHECK_VALIDITY,_SET_IP	983	4.8%	66.7%
_ITER_CHECK_RANGE,_SET_IP,_JUMP_TO_TOP,_CHECK_VALIDITY	983	4.8%	71.4%
_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE,_SET_IP,_JUMP_TO_TOP	983	4.8%	76.2%
_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE,_ITER_CHECK_RANGE,_SET_IP	983	4.8%	80.9%
_JUMP_TO_TOP,_CHECK_VALIDITY,STORE_NAME,_SET_IP	983	4.8%	85.7%
_CHECK_VALIDITY,STORE_NAME,_SET_IP,_BINARY_OP_ADD_INT	983	4.8%	90.5%
_CHECK_VALIDITY,_SET_IP,STORE_NAME,_CHECK_VALIDITY	983	4.8%	95.2%
_CHECK_VALIDITY,_SET_IP,_ITER_NEXT_RANGE,_GUARD_NOT_EXHAUSTED_RANGE	983	4.8%	100.0%

• Issue: Add UOp Pair counts to pystats #115178

EDIT: I see this has automatically requested a review from a huge number of people. This is my first time submitting a PR to CPython - please do forgive me if I've goofed this process up somehow.

---

📚 Documentation preview 📚: https://cpython-previews--115181.org.readthedocs.build/

[JeffersGlass]

Thank you both! @erlend-aasland your fix recipe worked a treat - I will be more careful about merging from main/pushing in the future.

[markshannon]

A couple of minor issues, but looks good in general.

[bedevere-app]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

[JeffersGlass]

Thank you for the corrections. I have made the requested changes; please review again.

[Fidget-Spinner]

@markshannon I'm going to merge this soon.

@JeffersGlass could you please fix the merge conflicts? Thanks!

[JeffersGlass]

Thanks @Fidget-Spinner - I've caught up with main and tests are passing.

[JeffersGlass]

Actually @Fidget-Spinner before you merge, I’ve seen something I missed in this morning’s merge from main, let me take care of that later today.

[Fidget-Spinner]

Ok just ping me again when you feel its ready, I will take a look then!

[JeffersGlass]

@Fidget-Spinner I've made the updates I wanted to, to fix detection of the different kinds of opcode pairs and give them good labels in the output. I've also just rebased on top of main; I think this is ready for review.

[markshannon]

Thanks @JeffersGlass for doing this.
This is going to be very useful for selecting micro-op pairs for the JIT.