[experiment] eliminate dead statements while retaining debugging information #140117

dianqk · 2025-04-21T14:20:44Z

I don't have a clear idea yet, but I'd like to take a look at perf first.

r? ghost

dianqk · 2025-04-21T22:10:06Z

[experiment] eliminate dead statements while retaining debugging information I don't have a clear idea yet, but I'd like to take a look at perf first. r? ghost

bors · 2025-04-21T22:11:17Z

⌛ Trying commit 3f1d09a with merge b3ad3fc...

bors · 2025-04-21T22:26:12Z

💔 Test failed - checks-actions

dianqk · 2025-04-22T00:36:10Z

@bors try @rust-timer queue

[experiment] eliminate dead statements while retaining debugging information I don't have a clear idea yet, but I'd like to take a look at perf first. r? ghost

bors · 2025-04-22T00:37:21Z

⌛ Trying commit ed418b0 with merge bf5df2d...

bors · 2025-04-22T02:32:05Z

☀️ Try build successful - checks-actions
Build commit: bf5df2d (bf5df2d521771a0774baccb586bfe531e205d258)

rust-timer · 2025-04-22T03:59:03Z

Finished benchmarking commit (bf5df2d): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	2.9%	[0.2%, 12.3%]	18
Regressions ❌ (secondary)	0.3%	[0.1%, 1.2%]	16
Improvements ✅ (primary)	-0.5%	[-1.3%, -0.2%]	12
Improvements ✅ (secondary)	-0.3%	[-0.5%, -0.2%]	15
All ❌✅ (primary)	1.5%	[-1.3%, 12.3%]	30

Max RSS (memory usage)

Results (primary -0.8%, secondary 2.9%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	1.5%	[0.4%, 3.2%]	7
Regressions ❌ (secondary)	2.9%	[2.9%, 2.9%]	1
Improvements ✅ (primary)	-1.9%	[-6.3%, -0.4%]	14
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.8%	[-6.3%, 3.2%]	21

Cycles

Results (primary 2.8%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	6.9%	[0.5%, 13.4%]	7
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.7%	[-1.4%, -0.4%]	8
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.8%	[-1.4%, 13.4%]	15

Binary size

Results (primary 0.1%, secondary -0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.0%, 4.6%]	44
Regressions ❌ (secondary)	0.2%	[0.1%, 0.3%]	13
Improvements ✅ (primary)	-0.3%	[-8.5%, -0.0%]	43
Improvements ✅ (secondary)	-0.2%	[-0.7%, -0.0%]	58
All ❌✅ (primary)	0.1%	[-8.5%, 4.6%]	87

Bootstrap: 774.01s -> 773.408s (-0.08%)
Artifact size: 365.04 MiB -> 365.06 MiB (0.01%)

dianqk · 2025-04-22T14:30:12Z

@bors try @rust-timer queue

bors · 2025-04-22T14:31:24Z

⌛ Trying commit a456a65 with merge 929ef38...

[experiment] eliminate dead statements while retaining debugging information I don't have a clear idea yet, but I'd like to take a look at perf first. r? ghost

rust-log-analyzer · 2025-04-22T14:40:13Z

The job mingw-check-tidy failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

info: removing rustup binaries
info: rustup is uninstalled
##[group]Image checksum input
mingw-check-tidy
# We use the ghcr base image because ghcr doesn't have a rate limit
# and the mingw-check-tidy job doesn't cache docker images in CI.
FROM ghcr.io/rust-lang/ubuntu:22.04

ARG DEBIAN_FRONTEND=noninteractive
RUN apt-get update && apt-get install -y --no-install-recommends \
  g++ \
  make \
---

COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
COPY host-x86_64/mingw-check/validate-error-codes.sh /scripts/

# NOTE: intentionally uses python2 for x.py so we can test it still works.
# validate-toolstate only runs in our CI, so it's ok for it to only support python3.
ENV SCRIPT TIDY_PRINT_DIFF=1 python2.7 ../x.py test \
           --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
#
# This file is autogenerated by pip-compile with Python 3.10
# by the following command:
#
#    pip-compile --allow-unsafe --generate-hashes reuse-requirements.in
---
#12 2.739 Building wheels for collected packages: reuse
#12 2.740   Building wheel for reuse (pyproject.toml): started
#12 2.953   Building wheel for reuse (pyproject.toml): finished with status 'done'
#12 2.954   Created wheel for reuse: filename=reuse-4.0.3-cp310-cp310-manylinux_2_35_x86_64.whl size=132719 sha256=5bb60f62728aaedff7162745ce743c7f2f55069b3e7f82e6a37d70df455797cc
#12 2.954   Stored in directory: /tmp/pip-ephem-wheel-cache-xxm5z5ay/wheels/3d/8d/0a/e0fc6aba4494b28a967ab5eaf951c121d9c677958714e34532
#12 2.957 Successfully built reuse
#12 2.957 Installing collected packages: boolean-py, binaryornot, tomlkit, reuse, python-debian, markupsafe, license-expression, jinja2, chardet, attrs
#12 3.343 Successfully installed attrs-23.2.0 binaryornot-0.4.4 boolean-py-4.0 chardet-5.2.0 jinja2-3.1.4 license-expression-30.3.0 markupsafe-2.1.5 python-debian-0.1.49 reuse-4.0.3 tomlkit-0.13.0
#12 3.344 WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
#12 3.875 Collecting virtualenv
#12 3.983   Downloading virtualenv-20.30.0-py3-none-any.whl (4.3 MB)
#12 4.159      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 4.3/4.3 MB 24.9 MB/s eta 0:00:00
#12 4.219 Collecting filelock<4,>=3.12.2
#12 4.246   Downloading filelock-3.18.0-py3-none-any.whl (16 kB)
#12 4.287 Collecting platformdirs<5,>=3.9.1
#12 4.315   Downloading platformdirs-4.3.7-py3-none-any.whl (18 kB)
#12 4.334 Collecting distlib<1,>=0.3.7
#12 4.370   Downloading distlib-0.3.9-py2.py3-none-any.whl (468 kB)
#12 4.377      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 469.0/469.0 KB 96.6 MB/s eta 0:00:00
#12 4.458 Installing collected packages: distlib, platformdirs, filelock, virtualenv
#12 4.640 Successfully installed distlib-0.3.9 filelock-3.18.0 platformdirs-4.3.7 virtualenv-20.30.0
#12 4.640 WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
#12 DONE 4.7s

#13 [7/8] COPY host-x86_64/mingw-check/validate-toolstate.sh /scripts/
#13 DONE 0.0s
---
DirectMap4k:      126912 kB
DirectMap2M:     6164480 kB
DirectMap1G:    12582912 kB
##[endgroup]
Executing TIDY_PRINT_DIFF=1 python2.7 ../x.py test            --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
+ TIDY_PRINT_DIFF=1 python2.7 ../x.py test --stage 0 src/tools/tidy tidyselftest --extra-checks=py,cpp
##[group]Building bootstrap
    Finished `dev` profile [unoptimized] target(s) in 0.05s
##[endgroup]
WARN: currently no CI rustc builds have rustc debug assertions enabled. Please either set `rust.debug-assertions` to `false` if you want to use download CI rustc or set `rust.download-rustc` to `false`.
[TIMING] core::build_steps::tool::LibcxxVersionTool { target: x86_64-unknown-linux-gnu } -- 0.216
---
fmt check
fmt: checked 5981 files
tidy check
tidy: Skipping binary file check, read-only filesystem
##[error]tidy error: /checkout/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs:208: TODO is used for tasks that should be done before merging a PR; If you want to leave a message in the codebase use FIXME
removing old virtual environment
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'venv'
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'virtualenv'
Requirement already satisfied: pip in ./build/venv/lib/python3.10/site-packages (25.0.1)
linting python files
All checks passed!
checking python file formatting
26 files already formatted
checking C++ file formatting
some tidy checks failed
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:01:47
  local time: Tue Apr 22 14:39:57 UTC 2025
  network time: Tue, 22 Apr 2025 14:39:58 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

bors · 2025-04-22T16:37:22Z

☀️ Try build successful - checks-actions
Build commit: 929ef38 (929ef387e0c93076fd6dbb37ad40756ba1b415fb)

rust-timer · 2025-04-22T18:03:30Z

Finished benchmarking commit (929ef38): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	5.1%	[0.5%, 12.1%]	9
Regressions ❌ (secondary)	0.2%	[0.1%, 0.3%]	13
Improvements ✅ (primary)	-0.5%	[-1.0%, -0.2%]	16
Improvements ✅ (secondary)	-0.3%	[-0.6%, -0.2%]	14
All ❌✅ (primary)	1.5%	[-1.0%, 12.1%]	25

Max RSS (memory usage)

Results (primary -0.9%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.6%	[0.6%, 7.7%]	5
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.3%	[-5.6%, -0.4%]	13
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.9%	[-5.6%, 7.7%]	18

Cycles

Results (primary 4.2%, secondary 2.4%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	9.1%	[2.5%, 13.4%]	5
Regressions ❌ (secondary)	2.4%	[2.0%, 2.6%]	8
Improvements ✅ (primary)	-0.7%	[-1.3%, -0.4%]	5
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	4.2%	[-1.3%, 13.4%]	10

Binary size

Results (primary 0.1%, secondary -0.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.0%, 4.6%]	46
Regressions ❌ (secondary)	0.2%	[0.0%, 0.3%]	14
Improvements ✅ (primary)	-0.3%	[-8.4%, -0.0%]	43
Improvements ✅ (secondary)	-0.2%	[-0.7%, -0.0%]	55
All ❌✅ (primary)	0.1%	[-8.4%, 4.6%]	89

Bootstrap: 774.196s -> 771.927s (-0.29%)
Artifact size: 365.08 MiB -> 365.06 MiB (-0.00%)

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 21, 2025

This comment has been minimized.

Sign in to view

dianqk force-pushed the mir-nop branch from 0d8e905 to 3f1d09a Compare April 21, 2025 22:09

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 21, 2025

This comment has been minimized.

Sign in to view

bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 21, 2025

dianqk force-pushed the mir-nop branch from 3f1d09a to ed418b0 Compare April 22, 2025 00:29

This comment has been minimized.

Sign in to view

rustbot added perf-regression Performance regression. and removed S-waiting-on-perf Status: Waiting on a perf run to be completed. labels Apr 22, 2025

dianqk added 4 commits April 22, 2025 22:26

mir: allow Nop to save a statement

51aa191

mir-opt: eliminate dead Ref assignments carrying debug information

e2e0291

codegen: ignore unsupported var debuginfo projection

081e59c

codegen: emit the debugging information for the dead code

a456a65

dianqk force-pushed the mir-nop branch from ed418b0 to a456a65 Compare April 22, 2025 14:29

This comment has been minimized.

Sign in to view

rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 22, 2025

This comment has been minimized.

Sign in to view

rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 22, 2025

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

[experiment] eliminate dead statements while retaining debugging information #140117

[experiment] eliminate dead statements while retaining debugging information #140117

dianqk commented Apr 21, 2025

This comment has been minimized.

dianqk commented Apr 21, 2025

This comment has been minimized.

bors commented Apr 21, 2025

This comment has been minimized.

This comment has been minimized.

bors commented Apr 21, 2025

dianqk commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

This comment has been minimized.

rust-timer commented Apr 22, 2025

dianqk commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

rust-log-analyzer commented Apr 22, 2025

bors commented Apr 22, 2025

This comment has been minimized.

rust-timer commented Apr 22, 2025

[experiment] eliminate dead statements while retaining debugging information #140117

Are you sure you want to change the base?

[experiment] eliminate dead statements while retaining debugging information #140117

Conversation

dianqk commented Apr 21, 2025

This comment has been minimized.

dianqk commented Apr 21, 2025

This comment has been minimized.

bors commented Apr 21, 2025

This comment has been minimized.

This comment has been minimized.

bors commented Apr 21, 2025

dianqk commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

This comment has been minimized.

rust-timer commented Apr 22, 2025

Overall result: ❌✅ regressions and improvements - please read the text below

dianqk commented Apr 22, 2025

This comment has been minimized.

bors commented Apr 22, 2025

rust-log-analyzer commented Apr 22, 2025

bors commented Apr 22, 2025

This comment has been minimized.

rust-timer commented Apr 22, 2025

Overall result: ❌✅ regressions and improvements - please read the text below