Skip to content

GVN transmutes of Immediate::Uninit to Immediate::Uninit - #163385

Merged
rust-bors[bot] merged 1 commit into
rust-lang:mainfrom
saethlin:gvn-uninit-transmutes
Oct 2, 2026
Merged

GVN transmutes of Immediate::Uninit to Immediate::Uninit#163385
rust-bors[bot] merged 1 commit into
rust-lang:mainfrom
saethlin:gvn-uninit-transmutes

Conversation

@saethlin

@saethlin saethlin commented Sep 26, 2026

Copy link
Copy Markdown
Member

This makes us generate the intended MIR for #159454.

@rustbot

rustbot commented Sep 26, 2026

Copy link
Copy Markdown
Collaborator

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

@rustbot 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 Sep 26, 2026
@rustbot

rustbot commented Sep 26, 2026

Copy link
Copy Markdown
Collaborator

r? @camelid

rustbot has assigned @camelid.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

Why was this reviewer chosen?

The reviewer was selected based on:

  • Owners of files modified in this PR: compiler
  • compiler expanded to 77 candidates
  • Random selection from 19 candidates

@saethlin

saethlin commented Sep 26, 2026

Copy link
Copy Markdown
Member Author

I don't expect to see much of an impact if any, but still:

@bors try @rust-timer queue

@rust-timer

This comment has been minimized.

Sign in to view
@rust-bors

This comment has been minimized.

Sign in to view
@rustbot rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 26, 2026
rust-bors Bot pushed a commit that referenced this pull request Sep 26, 2026
@bors
Auto merge of #163385 - saethlin:gvn-uninit-transmutes, r=<try>
84096a5 
GVN transmutes of Immediate::Uninit to Immediate::Uninit
@rust-bors

rust-bors Bot commented Sep 26, 2026

Copy link
Copy Markdown
Contributor

☀️ Try build successful (CI)
Build commit: 84096a5 (84096a5a19cfcdeacdcd479939fed5f7d79c88dc)
Base parent: a22b02e (a22b02eaecd6ac937d752139c79d0159c725932d)

@rust-timer

This comment has been minimized.

Sign in to view
@rust-timer

rust-timer commented Sep 26, 2026

Copy link
Copy Markdown
Collaborator

Finished benchmarking commit (84096a5): comparison URL.

Overall result: ❌ regressions - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 0.4% [0.4%, 0.4%] 1
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) - - 0

Max RSS (memory usage)

Results (secondary 3.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 3.5% [2.7%, 4.2%] 3
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) - - 0

Cycles

Results (primary 15.9%, secondary -2.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

mean range count
Regressions ❌
(primary)		 15.9% [4.6%, 22.6%] 3
Regressions ❌
(secondary)		 4.3% [0.7%, 6.9%] 5
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 -8.3% [-9.8%, -6.1%] 6
All ❌✅ (primary) 15.9% [4.6%, 22.6%] 3

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 489.175s -> 489.292s (0.02%)
Artifact size: 407.02 MiB -> 406.39 MiB (-0.15%)

@rustbot rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 26, 2026
oli-obk
oli-obk approved these changes Oct 1, 2026
View reviewed changes

@oli-obk oli-obk left a comment •
edited by rustbot
Loading

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

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

@bors r+ rollup

View changes since this review

@rust-bors

rust-bors Bot commented Oct 1, 2026

Copy link
Copy Markdown
Contributor

📌 Commit 49577f8 has been approved by oli-obk

It is now in the queue for this repository.

@rust-bors rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Oct 1, 2026
@oli-obk oli-obk assigned oli-obk and unassigned camelid Oct 1, 2026
JonathanBrouwer added a commit to JonathanBrouwer/rust that referenced this pull request Oct 1, 2026
@JonathanBrouwer
Rollup merge of rust-lang#163385 - saethlin:gvn-uninit-transmutes, r=…
1d344c2 
…oli-obk

GVN transmutes of Immediate::Uninit to Immediate::Uninit

This makes us generate the intended MIR for rust-lang#159454.
@JonathanBrouwer JonathanBrouwer mentioned this pull request Oct 1, 2026
Closed
rust-bors Bot pushed a commit that referenced this pull request Oct 1, 2026
@bors
Auto merge of #163605 - JonathanBrouwer:rollup-QR3gwZd, r=JonathanBro…
c546f2e 
…uwer

Rollup of 9 pull requests

Successful merges:

 - #163461 (Improve diagnostic deduplication)
 - #159021 (windows-gnu: enable native TLS)
 - #161467 (wfcheck: name the item that discards an unused type parameter)
 - #162618 (trait_selection: Preserve eager normalization failures)
 - #163064 (Avoid computing overflowed goal chains for crate dependencies)
 - #163360 ([rustdoc] Correctly handle rustc_allow_incoherent_impl on primitive methods)
 - #163385 (GVN transmutes of Immediate::Uninit to Immediate::Uninit)
 - #163590 (Make `AllocatorNightly` less clever)
 - #163599 (Add union pattern reference change to relnotes)
@JonathanBrouwer JonathanBrouwer mentioned this pull request Oct 1, 2026
Merged
rust-bors Bot pushed a commit that referenced this pull request Oct 1, 2026
@bors
Auto merge of #163609 - JonathanBrouwer:rollup-VGVBPvm, r=JonathanBro…
c16ae9d 
…uwer

Rollup of 20 pull requests

Successful merges:

 - #163483 (Bump bootstrap compiler to 1.100.0 beta)
 - #161380 (only rerun const eval in next-solver if the const actually references opaques)
 - #162900 (Some refactorings around metadata encoding)
 - #163461 (Improve diagnostic deduplication)
 - #163580 (Provide better doc code example for `UnixDatagram::bind_addr` and `UnixListener::bind_addr`)
 - #163584 ([triagebot] Ping me for debugger visualizer changes)
 - #159021 (windows-gnu: enable native TLS)
 - #161467 (wfcheck: name the item that discards an unused type parameter)
 - #162618 (trait_selection: Preserve eager normalization failures)
 - #162904 (Fix ICE for ambiguous candidates on method probing)
 - #163064 (Avoid computing overflowed goal chains for crate dependencies)
 - #163281 (Add `f16` inline ASM support to `spirv.rs`)
 - #163314 (move `#[macro_export]` on declarative macro check to `rustc_attr_parsing`)
 - #163360 ([rustdoc] Correctly handle rustc_allow_incoherent_impl on primitive methods)
 - #163385 (GVN transmutes of Immediate::Uninit to Immediate::Uninit)
 - #163405 (Remove some #[linkage] options)
 - #163530 (`const impl PartialEq` for `f16b`)
 - #163581 (do not suggest precise capturing when the opaque span is in a macro expansion)
 - #163590 (Make `AllocatorNightly` less clever)
 - #163599 (Add union pattern reference change to relnotes)
rust-bors Bot pushed a commit that referenced this pull request Oct 1, 2026
@bors
Auto merge of #163609 - JonathanBrouwer:rollup-VGVBPvm, r=JonathanBro…
bdbc480 
…uwer

Rollup of 20 pull requests

Successful merges:

 - #163483 (Bump bootstrap compiler to 1.100.0 beta)
 - #161380 (only rerun const eval in next-solver if the const actually references opaques)
 - #162900 (Some refactorings around metadata encoding)
 - #163461 (Improve diagnostic deduplication)
 - #163580 (Provide better doc code example for `UnixDatagram::bind_addr` and `UnixListener::bind_addr`)
 - #163584 ([triagebot] Ping me for debugger visualizer changes)
 - #159021 (windows-gnu: enable native TLS)
 - #161467 (wfcheck: name the item that discards an unused type parameter)
 - #162618 (trait_selection: Preserve eager normalization failures)
 - #162904 (Fix ICE for ambiguous candidates on method probing)
 - #163064 (Avoid computing overflowed goal chains for crate dependencies)
 - #163281 (Add `f16` inline ASM support to `spirv.rs`)
 - #163314 (move `#[macro_export]` on declarative macro check to `rustc_attr_parsing`)
 - #163360 ([rustdoc] Correctly handle rustc_allow_incoherent_impl on primitive methods)
 - #163385 (GVN transmutes of Immediate::Uninit to Immediate::Uninit)
 - #163405 (Remove some #[linkage] options)
 - #163530 (`const impl PartialEq` for `f16b`)
 - #163581 (do not suggest precise capturing when the opaque span is in a macro expansion)
 - #163590 (Make `AllocatorNightly` less clever)
 - #163599 (Add union pattern reference change to relnotes)
rust-bors Bot pushed a commit that referenced this pull request Oct 2, 2026
@bors
Auto merge of #163609 - JonathanBrouwer:rollup-VGVBPvm, r=JonathanBro…
a5c10c3 
…uwer

Rollup of 20 pull requests

Successful merges:

 - #163483 (Bump bootstrap compiler to 1.100.0 beta)
 - #161380 (only rerun const eval in next-solver if the const actually references opaques)
 - #162900 (Some refactorings around metadata encoding)
 - #163461 (Improve diagnostic deduplication)
 - #163580 (Provide better doc code example for `UnixDatagram::bind_addr` and `UnixListener::bind_addr`)
 - #163584 ([triagebot] Ping me for debugger visualizer changes)
 - #159021 (windows-gnu: enable native TLS)
 - #161467 (wfcheck: name the item that discards an unused type parameter)
 - #162618 (trait_selection: Preserve eager normalization failures)
 - #162904 (Fix ICE for ambiguous candidates on method probing)
 - #163064 (Avoid computing overflowed goal chains for crate dependencies)
 - #163281 (Add `f16` inline ASM support to `spirv.rs`)
 - #163314 (move `#[macro_export]` on declarative macro check to `rustc_attr_parsing`)
 - #163360 ([rustdoc] Correctly handle rustc_allow_incoherent_impl on primitive methods)
 - #163385 (GVN transmutes of Immediate::Uninit to Immediate::Uninit)
 - #163405 (Remove some #[linkage] options)
 - #163530 (`const impl PartialEq` for `f16b`)
 - #163581 (do not suggest precise capturing when the opaque span is in a macro expansion)
 - #163590 (Make `AllocatorNightly` less clever)
 - #163599 (Add union pattern reference change to relnotes)
@rust-bors
rust-bors Bot merged commit 8dd9986 into rust-lang:main Oct 2, 2026
14 checks passed
@rustbot rustbot added this to the 1.101.0 milestone Oct 2, 2026
rust-bors Bot pushed a commit that referenced this pull request Oct 2, 2026
@bors
Unrolled build for #163385 in rollup 163609
20769d9 
Rollup merge of #163385 - saethlin:gvn-uninit-transmutes, r=oli-obk

GVN transmutes of Immediate::Uninit to Immediate::Uninit

This makes us generate the intended MIR for #159454.
flip1995 pushed a commit to flip1995/rust-clippy that referenced this pull request Oct 3, 2026
@bors
Auto merge of #163609 - JonathanBrouwer:rollup-VGVBPvm, r=JonathanBro…
b022d5c 
…uwer

Rollup of 20 pull requests

Successful merges:

 - rust-lang/rust#163483 (Bump bootstrap compiler to 1.100.0 beta)
 - rust-lang/rust#161380 (only rerun const eval in next-solver if the const actually references opaques)
 - rust-lang/rust#162900 (Some refactorings around metadata encoding)
 - rust-lang/rust#163461 (Improve diagnostic deduplication)
 - rust-lang/rust#163580 (Provide better doc code example for `UnixDatagram::bind_addr` and `UnixListener::bind_addr`)
 - rust-lang/rust#163584 ([triagebot] Ping me for debugger visualizer changes)
 - rust-lang/rust#159021 (windows-gnu: enable native TLS)
 - rust-lang/rust#161467 (wfcheck: name the item that discards an unused type parameter)
 - rust-lang/rust#162618 (trait_selection: Preserve eager normalization failures)
 - rust-lang/rust#162904 (Fix ICE for ambiguous candidates on method probing)
 - rust-lang/rust#163064 (Avoid computing overflowed goal chains for crate dependencies)
 - rust-lang/rust#163281 (Add `f16` inline ASM support to `spirv.rs`)
 - rust-lang/rust#163314 (move `#[macro_export]` on declarative macro check to `rustc_attr_parsing`)
 - rust-lang/rust#163360 ([rustdoc] Correctly handle rustc_allow_incoherent_impl on primitive methods)
 - rust-lang/rust#163385 (GVN transmutes of Immediate::Uninit to Immediate::Uninit)
 - rust-lang/rust#163405 (Remove some #[linkage] options)
 - rust-lang/rust#163530 (`const impl PartialEq` for `f16b`)
 - rust-lang/rust#163581 (do not suggest precise capturing when the opaque span is in a macro expansion)
 - rust-lang/rust#163590 (Make `AllocatorNightly` less clever)
 - rust-lang/rust#163599 (Add union pattern reference change to relnotes)
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@oli-obk oli-obk oli-obk approved these changes

Assignees

@oli-obk oli-obk

Labels

S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.

Projects

None yet

Milestone

1.101.0

Development

Successfully merging this pull request may close these issues.

5 participants

@saethlin @rustbot @rust-timer @oli-obk @camelid