T-compiler Meeting Agenda 2023-08-10

--- tags: weekly, rustc type: docs --- # T-compiler Meeting Agenda 2023-08-10 ## Announcements - [wg-async deep dive: 2024 Prelude + `Future::map`](https://www.google.com/calendar/event?eid=ajVtNGowYjlzdDNhM2VwZG9vNjg4OTlzNDBfMjAyMzA4MTBUMTYwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-08-10T12:00:00-04:00> - [AFIT/RPITIT Impl Triage](https://www.google.com/calendar/event?eid=N2VsaWszdm9rY3NhdDF1MjdyMjVqajNpcWVfMjAyMzA4MTBUMjAwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-08-10T16:00:00-04:00> - Reminder: if you see a PR/issue that seems like there might be legal implications due to copyright/IP/etc, please let us know (or at least message @_**davidtwco** or @_**Wesley Wiser** so we can pass it along). ### Other WG meetings ([calendar link](https://calendar.google.com/calendar/embed?src=6u5rrtce6lrtv07pfi3damgjus%40group.calendar.google.com)) - [Types team meeting](https://www.google.com/calendar/event?eid=MTg3MDhpdTc3YXBqMGMzbnNxanUwdWZnazhfMjAyMzA4MTRUMTQwMDAwWiA2dTVycnRjZTZscnR2MDdwZmkzZGFtZ2p1c0Bn) at <time:2023-08-14T10:00:00-04:00> ## MCPs/FCPs - New MCPs (take a look, see if you like them!) - No new proposals this time. - Old MCPs (not seconded, take a look) - "Cell Broadband Engine SPU support" [compiler_team#614](https://github.com/rust-lang/compiler-team/issues/614) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Cell.20Broadband.20Engine.20SPU.20support.20compiler-team.23614)) - "Add support for Zephyr OS" [compiler_team#629](https://github.com/rust-lang/compiler-team/issues/629) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20support.20for.20Zephyr.20OS.20compiler-team.23629)) - "Consistently use \"region\" terminology in later stages of the compiler" [compiler_team#634](https://github.com/rust-lang/compiler-team/issues/634) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Consistently.20use.20.22region.22.20terminology.20in.20.E2.80.A6.20compiler-team.23634)) - "Add a new `--build-id` flag to rustc" [compiler_team#635](https://github.com/rust-lang/compiler-team/issues/635) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20a.20new.20.60--build-id.60.20flag.20to.20rustc.20compiler-team.23635)) - "Simplify and improve explicitness of the check-cfg syntax" [compiler_team#636](https://github.com/rust-lang/compiler-team/issues/636) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Simplify.20and.20improve.20explicitness.20of.20the.20.E2.80.A6.20compiler-team.23636)) - "Add support for visionOS targets" [compiler_team#642](https://github.com/rust-lang/compiler-team/issues/642) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20support.20for.20visionOS.20targets.20compiler-team.23642)) - "Add illumos Tier3 targets" [compiler_team#644](https://github.com/rust-lang/compiler-team/issues/644) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20illumos.20Tier3.20targets.20compiler-team.23644)) - "Migrate away from u32 as an offset/length type" [compiler_team#647](https://github.com/rust-lang/compiler-team/issues/647) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Migrate.20away.20from.20u32.20as.20an.20offset.2Flength.E2.80.A6.20compiler-team.23647)) - "Add `builtin:$path` option to the `-L` flag" [compiler_team#659](https://github.com/rust-lang/compiler-team/issues/659) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20.60builtin.3A.24path.60.20option.20to.20the.20.60-L.60.20fl.E2.80.A6.20compiler-team.23659)) - Pending FCP requests (check your boxes!) - "Retire the mailing list and make all decisions on zulip" [compiler_team#649](https://github.com/rust-lang/compiler-team/issues/649) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Retire.20the.20mailing.20list.20and.20make.20all.20deci.E2.80.A6.20compiler-team.23649)) - concerns raised - "Tracking issue for dyn upcasting coercion" [rust#65991](https://github.com/rust-lang/rust/issues/65991#issuecomment-1670127912) - concerns raised, notably about the stabilization requirements (from [here](https://github.com/rust-lang/rust/issues/65991#issuecomment-1670355101)) - "Support overriding `warnings` level for a specific lint via command line" [rust#113307](https://github.com/rust-lang/rust/pull/113307#issuecomment-1621305927) - "Stabilize `PATH` option for `--print KIND=PATH`" [rust#114183](https://github.com/rust-lang/rust/pull/114183#issuecomment-1656270266) - Things in FCP (make sure you're good with it) - "Add a blanket flag to enable/disable codegen UB checks" [compiler_team#625](https://github.com/rust-lang/compiler-team/issues/625) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Add.20a.20blanket.20flag.20to.20enable.2Fdisable.20code.E2.80.A6.20compiler-team.23625)) - "[MCP] proposing a macros working group" [compiler_team#637](https://github.com/rust-lang/compiler-team/issues/637) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/.5BMCP.5D.20proposing.20a.20macros.20woriking.20group.20compiler-team.23637)) - "Disallow non-identifier-valid --extern crate names " [compiler_team#650](https://github.com/rust-lang/compiler-team/issues/650) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Disallow.20non-identifier-valid.20--extern.20cr.E2.80.A6.20compiler-team.23650)) - "Windows support schedule 2024" [compiler_team#651](https://github.com/rust-lang/compiler-team/issues/651) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Windows.20support.20schedule.202024.20compiler-team.23651)) - "New tier-3 targets for TEEOS" [compiler_team#652](https://github.com/rust-lang/compiler-team/issues/652) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/New.20tier-3.20targets.20for.20TEEOS.20compiler-team.23652)) - "Expose default_hidden_visibility as a rustc command line option" [compiler_team#656](https://github.com/rust-lang/compiler-team/issues/656) ([Zulip](https://rust-lang.zulipchat.com/#narrow/stream/233931-xxx/topic/Expose.20default_hidden_visibility.20as.20a.20rus.E2.80.A6.20compiler-team.23656)) - Accepted MCPs - "Revise error code documentation standard" [compiler-team#615](https://github.com/rust-lang/compiler-team/issues/615) - "[MCP] proposing a macros working group" [compiler-team#637](https://github.com/rust-lang/compiler-team/issues/637) - "Disallow non-identifier-valid --extern crate names " [compiler-team#650](https://github.com/rust-lang/compiler-team/issues/650) - "Windows support schedule 2024" [compiler-team#651](https://github.com/rust-lang/compiler-team/issues/651) - "New tier-3 targets for TEEOS" [compiler-team#652](https://github.com/rust-lang/compiler-team/issues/652) - "Expose default_hidden_visibility as a rustc command line option" [compiler-team#656](https://github.com/rust-lang/compiler-team/issues/656) - Finalized FCPs (disposition merge) - "check for non-defining uses of RPIT" [rust#112842](https://github.com/rust-lang/rust/pull/112842) - "add notes about non-compliant FP behavior on 32bit x86 targets" [rust#113053](https://github.com/rust-lang/rust/pull/113053) - "Mention style for new syntax in tracking issue template" [rust#113586](https://github.com/rust-lang/rust/pull/113586) - "Make `unconditional_recursion` warning detect recursive drops" [rust#113902](https://github.com/rust-lang/rust/pull/113902) ### WG checkins - @_*WG-async-foundations* by @**nikomatsakis** and @**tmandry** ([previous checkin](https://hackmd.io/EewyTLZXQpmtfaH633GU-A#WG-checkins)): > Checkin text ## Backport nominations [T-compiler stable](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Abeta-nominated+-label%3Abeta-accepted+label%3AT-compiler) / [T-compiler beta](https://github.com/rust-lang/rust/issues?q=is%3Aall+label%3Astable-nominated+-label%3Astable-accepted+label%3AT-compiler) - :beta: "lint/ctypes: only try normalize" [rust#113921](https://github.com/rust-lang/rust/pull/113921) - Fixes P-medium #113900, ICE when trying to compile an empty crate pulling a specific crate `abi_stable` as dependency  - :beta: "Restrict linker version script of proc-macro crates to just its two symbols" [rust#114470](https://github.com/rust-lang/rust/pull/114470) - Fixes #111888 and #99978 - "Restrict linker version script of proc-macro crates to just the two symbols of each proc-macro crate."  - No stable nominations for `T-compiler` this time. ## PRs S-waiting-on-team [T-compiler](https://github.com/rust-lang/rust/pulls?q=is%3Aopen+label%3AS-waiting-on-team+label%3AT-compiler) - Other issues [in progress or waiting on other teams](https://hackmd.io/XYr1BrOWSiqCrl8RCWXRaQ) ## Issues of Note ### Short Summary - [1 T-compiler P-critical issues](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-critical) - [0 of those are unassigned](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-critical+no%3Aassignee) - [54 T-compiler P-high issues](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high) - [27 of those are unassigned](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-compiler+label%3AP-high+no%3Aassignee) - [0 P-critical, 1 P-high, 3 P-medium, 1 P-low regression-from-stable-to-beta](https://github.com/rust-lang/rust/labels/regression-from-stable-to-beta) - [0 P-critical, 1 P-high, 3 P-medium, 2 P-low regression-from-stable-to-nightly](https://github.com/rust-lang/rust/labels/regression-from-stable-to-nightly) - [1 P-critical, 33 P-high, 100 P-medium, 18 P-low regression-from-stable-to-stable](https://github.com/rust-lang/rust/labels/regression-from-stable-to-stable) ### P-critical [T-compiler](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-compiler) - "Recursion using `extern "C"` causes miscompilation" [rust#114312](https://github.com/rust-lang/rust/issues/114312) - Seems to have regressed in the LLVM 16 upgrade, #109474 ([comment](https://github.com/rust-lang/rust/issues/114312#issuecomment-1659354950)) - Should be resolved by LLVM fix [llvm-project#150](https://github.com/rust-lang/llvm-project/pull/150) - PR is also `I-compiler-nominated` to discuss an LLVM 16 backport - "Miscompilation when matching on an enum after printing Hello world" [rust#114691](https://github.com/rust-lang/rust/issues/114691) - Regressed in LLVM 17 upgrade - @**Nikita Popov** reported upstream [llvm-project#64589](https://github.com/llvm/llvm-project/issues/64589) and self-assigned (:heart:) [T-types](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-types) - No `P-critical` issues for `T-types` this time. [T-rustdoc](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AP-critical+label%3AT-rustdoc) - No `P-critical` issues for `T-rustdoc` this time. ### P-high regressions [P-high beta regressions](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3Aregression-from-stable-to-beta+label%3AP-high+-label%3AT-infra+-label%3AT-libs+-label%3AT-libs-api+-label%3AT-release+-label%3AT-rustdoc+-label%3AT-core) - No `P-high` beta regressions this time. [Unassigned P-high nightly regressions](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3Aregression-from-stable-to-nightly+label%3AP-high+no%3Aassignee+-label%3AT-infra+-label%3AT-libs+-label%3AT-libs-api+-label%3AT-release+-label%3AT-rustdoc+-label%3AT-core+) - "regex miscompiles with aggressive optimization flags" [rust#114488](https://github.com/rust-lang/rust/issues/114488) - bisected to #109025 - (confirm P-high)? ## Performance logs > [triage logs for 2023-08-08](https://github.com/rust-lang/rustc-perf/blob/master/triage/2023-08-08.md) Overall a very positive week, primarily due to an [upgrade to LLVM 17](https://github.com/rust-lang/rust/pull/114048) and some changes to [lint execution](https://github.com/rust-lang/rust/pull/113734). Memory usage is down [4-7%](https://perf.rust-lang.org/?start=828bdc2c26f5c95773c4ecf72870919f16417b66&end=443c3161dd04f4c1b656a626f9079921bee9c326&absolute=false&stat=max-rss&kind=percentfromfirst) over the last week and wall times are down [3-5%](https://perf.rust-lang.org/?start=828bdc2c26f5c95773c4ecf72870919f16417b66&end=443c3161dd04f4c1b656a626f9079921bee9c326&absolute=false&stat=wall-time&kind=percentfromfirst). Triage done by **@simulacrum**. Revision range: [828bdc2c26f5c95773c4ecf72870919f16417b66..443c3161dd04f4c1b656a626f9079921bee9c326](https://perf.rust-lang.org/?start=828bdc2c26f5c95773c4ecf72870919f16417b66&end=443c3161dd04f4c1b656a626f9079921bee9c326&absolute=false&stat=instructions%3Au) **Summary**: | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:---------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -3.1% | [-7.1%, -1.2%] | 253 | | Improvements (secondary) | -4.1% | [-28.4%, -0.3%] | 233 | | All (primary) | -3.1% | [-7.1%, -1.2%] | 253 | 2 Regressions, 7 Improvements, 2 Mixed; 2 of them in rollups 64 artifact comparisons made in total #### Regressions Rollup of 9 pull requests [#114481](https://github.com/rust-lang/rust/pull/114481) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=fe896efa974ea759b10b9754234ae61e9cab28b3&end=e4c14468460b22ac7a289a422fb7fee606e12a0b&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:----:|:------------:|:-----:| | Regressions (primary) | 0.8% | [0.4%, 1.5%] | 80 | | Regressions (secondary) | 0.7% | [0.2%, 1.2%] | 25 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | - | - | 0 | | All (primary) | 0.8% | [0.4%, 1.5%] | 80 | Unclear what is causing this regression. It's entirely limited to the incr-patched and incr-unchanged scenarios, and digging into one of the benchmarks (bitmaps-3.1.0 check incr-unchanged) seems to show a mix of noise and, in aggregate, significant improvements over the last several days. Not clear which PR in this rollup could have caused this change in behavior. See [these comments](https://github.com/rust-lang/rust/pull/114481#issuecomment-1666438972) for some more details. Re-enable atomic loads and stores for all RISC-V targets [#98333](https://github.com/rust-lang/rust/pull/98333) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e173a8e6634d787a1529ff6ec5dc63273425ca34&end=90f0b24ad3e7fc0dc0e419c9da30d74629cd5736&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:----:|:------------:|:-----:| | Regressions (primary) | 0.8% | [0.4%, 1.3%] | 18 | | Regressions (secondary) | 0.6% | [0.2%, 0.9%] | 12 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | - | - | 0 | | All (primary) | 0.8% | [0.4%, 1.3%] | 18 | This PR has a very similar regression profile to the previous rollup in this list (#114481). #### Improvements Remove `constness` from `TraitPredicate` [#114202](https://github.com/rust-lang/rust/pull/114202) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=7637653b9fdd2b2f2dc3b378891eb5cf6aea9f5d&end=20747af8940cf683970e76ec9a433305940c05f3&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.7% | [-0.9%, -0.4%] | 16 | | Improvements (secondary) | -0.6% | [-1.2%, -0.3%] | 13 | | All (primary) | -0.7% | [-0.9%, -0.4%] | 16 | cg_llvm: stop identifying ADTs in LLVM IR [#114350](https://github.com/rust-lang/rust/pull/114350) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=098c1db7e55e7229a520a2ec8e460e1e300e109b&end=73dc6f03a2a8c0e8b8b25fb97d7f4805995ce0b9&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.8% | [-1.2%, -0.6%] | 5 | | Improvements (secondary) | -1.1% | [-1.5%, -0.6%] | 6 | | All (primary) | -0.8% | [-1.2%, -0.6%] | 5 | Convert builtin "global" late lints to run per module [#113734](https://github.com/rust-lang/rust/pull/113734) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=fca59ab5f0e7df7d816bed77a32abc0045ebe80b&end=67626b8e89ff57269f1d67cb9bc037088c058b42&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:---------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | 0.5% | [0.4%, 0.8%] | 3 | | Improvements (primary) | -1.7% | [-3.4%, -0.2%] | 88 | | Improvements (secondary) | -4.2% | [-26.5%, -0.2%] | 85 | | All (primary) | -1.7% | [-3.4%, -0.2%] | 88 | parent_module_from_def_id does not need to be a query. [#114516](https://github.com/rust-lang/rust/pull/114516) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e59540968e0c6fc3c37d92a639b83fc8fcee5e81&end=5973bfbd38fcefb63090a588733931e933498dfd&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.3% | [0.2%, 0.4%] | 2 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -1.4% | [-2.0%, -1.1%] | 17 | | Improvements (secondary) | -1.2% | [-1.5%, -0.3%] | 11 | | All (primary) | -1.2% | [-2.0%, 0.4%] | 19 | Steal MIR for CTFE when possible. [#114502](https://github.com/rust-lang/rust/pull/114502) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=85fbb571497d13cfb828de9b0d3e78656b9203c1&end=f3623871cfa0763c95ebd6ceafaa6dc2e44ca68f&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.6% | [-0.6%, -0.6%] | 1 | | Improvements (secondary) | -1.5% | [-2.6%, -0.5%] | 19 | | All (primary) | -0.6% | [-0.6%, -0.6%] | 1 | Update to LLVM 17 [#114048](https://github.com/rust-lang/rust/pull/114048) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=03a119b0b0e310d22d94399b24ed030056050f13&end=443c3161dd04f4c1b656a626f9079921bee9c326&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:---------------:|:-----:| | Regressions (primary) | - | - | 0 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -2.2% | [-5.6%, -0.8%] | 173 | | Improvements (secondary) | -2.2% | [-12.9%, -0.5%] | 199 | | All (primary) | -2.2% | [-5.6%, -0.8%] | 173 | This represents a large win across multiple benchmarks. Unfortunately it also regresses artifact sizes for libLLVM.so by 50MB. Investigation into why is [ongoing](https://github.com/rust-lang/rust/pull/114048#issuecomment-1669252031). Do not run ConstProp on mir_for_ctfe. [#114459](https://github.com/rust-lang/rust/pull/114459) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=67626b8e89ff57269f1d67cb9bc037088c058b42&end=1cabb8ed2301faf193132e71ca5b10f82913e48a&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.2% | [0.2%, 0.2%] | 1 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | -0.8% | [-1.2%, -0.5%] | 8 | | Improvements (secondary) | -1.7% | [-3.0%, -1.1%] | 7 | | All (primary) | -0.7% | [-1.2%, 0.2%] | 9 | The one regression is actually within noise floor for the relevant benchmark. #### Mixed Optimize `Iterator` implementation for `&mut impl Iterator + Sized` [#111200](https://github.com/rust-lang/rust/pull/111200) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=9565b68b741fd0466b3af075139e819e7d73ee38&end=eb088b8b9d98f1af1b0e61bbdcd8686e1b0db7b6&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 0.4% | [0.3%, 0.5%] | 6 | | Regressions (secondary) | - | - | 0 | | Improvements (primary) | - | - | 0 | | Improvements (secondary) | -0.7% | [-0.9%, -0.5%] | 2 | | All (primary) | 0.4% | [0.3%, 0.5%] | 6 | Rollup of 7 pull requests [#114604](https://github.com/rust-lang/rust/pull/114604) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=443c3161dd04f4c1b656a626f9079921bee9c326&end=8e7fd551311d424e4e63fa45906a2a928fce96a7&stat=instructions:u) | (instructions:u) | mean | range | count | |:------------------------:|:-----:|:--------------:|:-----:| | Regressions (primary) | 1.4% | [0.4%, 2.0%] | 3 | | Regressions (secondary) | 1.2% | [1.1%, 1.3%] | 6 | | Improvements (primary) | -0.7% | [-0.9%, -0.4%] | 2 | | Improvements (secondary) | -1.0% | [-1.5%, -0.5%] | 2 | | All (primary) | 0.5% | [-0.9%, 2.0%] | 5 | Investigation into cause is [ongoing](https://github.com/rust-lang/rust/pull/114604#issuecomment-1669350724). ## Nominated Issues [T-compiler](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AI-compiler-nominated) - "Recursion using `extern "C"` causes miscompilation" [rust#114312](https://github.com/rust-lang/rust/issues/114312) - Nominated by @**Josh Stone (cuviper)** in [comment](https://github.com/rust-lang/rust/issues/114312#issuecomment-1670482403): LLVM PR author @_**DianQK** suggests an LLVM 16 backport - sort of unusual for us - "Non-temporal stores (and _mm_stream operations in stdarch) break our memory model" [rust#114582](https://github.com/rust-lang/rust/issues/114582) - `I-lang-nominated`, FIY to T-compiler - ([comment](https://github.com/rust-lang/rust/issues/114582#issuecomment-1670907861)) The nontemporal-store intrinsic was introduced in [fe53a81](https://github.com/rust-lang/rust/commit/fe53a8106dfb54b5fe04d2ce7e8ee6472b0d5b16), with a comment saying this will likely never be stable but then accidentally stabilized in [stdarch#414](https://github.com/rust-lang/stdarch/pull/414) - "Associated type constraints on super traits allowing for unsound transmutation to trait objects" [rust#114389](https://github.com/rust-lang/rust/issues/114389) - nominated by @**apiraino** ([comment](https://github.com/rust-lang/rust/issues/114389#issuecomment-1669310386)) - Prioritization [comment](https://rust-lang.zulipchat.com/#narrow/stream/245100-t-compiler.2Fwg-prioritization.2Falerts/topic/.23114389.20Associated.20type.20constraints.20on.20super.20traits.20allowin.E2.80.A6/near/382891948): "If understand correctly this is a symptom of another old issue #57893. I cannot grasp the context but the linked #57893 is an unsoundeness marked as P-high since 2019, then demoted in 2020, then again P-high" [RFC](https://github.com/rust-lang/rfcs/issues?q=is%3Aopen+label%3AI-compiler-nominated) - No I-compiler-nominated RFCs this time. ### Oldest PRs waiting for review - "`-Z trait-solver=next`: Deduplicate region constraints in query responses" [rust#111172](https://github.com/rust-lang/rust/pull/111172) - cc: @**lcnr** - "Rebased: Mark drop calls in landing pads cold instead of noinline" [rust#102099](https://github.com/rust-lang/rust/pull/102099)(last review activity: 2 months ago) - @**Nikita Popov** asking for someone to look into the MSVC in this PR ([comment](https://github.com/rust-lang/rust/pull/102099#issuecomment-1671103591)) - Seems kind of related to the discussion we had last week about MSVC target tier support ([summary](https://github.com/rust-lang/rust/issues/112480#issuecomment-1665258086)) - "Only emit one error per unsized binding, instead of one per usage" [rust#113183](https://github.com/rust-lang/rust/pull/113183)(last review activity: about 41 days ago) - was reassigned to @_**TaKO8Ki**, reroll to someone else of WG-diag? - "fix: extract rustc_test_marker attr in test_case" [rust#113315](https://github.com/rust-lang/rust/pull/113315)(last review activity: about 37 days ago) - assigned to @**Jack Huey** then @**Vadim Petrochenkov** was mentioned. Reroll this one? ## Next week's WG checkins - TBA Next meetings' agenda draft: https://hackmd.io/c9KaX3GNRZSKbIUp3SJpJw

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