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always check alignment during CTFE #104616
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@bors try @rust-timer queue |
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⌛ Trying commit 398905f2142d881f18a069b92f503f7f7d2cdb75 with merge 66a90ebb65988141d56cac36290f07711b1b1e2d... |
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☀️ Try build successful - checks-actions |
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Finished benchmarking commit (66a90ebb65988141d56cac36290f07711b1b1e2d): comparison URL. Overall result: ✅ improvements - no action neededBenchmarking 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. @bors rollup=never Instruction countThis is a highly reliable metric that was used to determine the overall result at the top of this comment.
Max RSS (memory usage)ResultsThis 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.
CyclesThis benchmark run did not return any relevant results for this metric. |
Improvement? This has to be noise, right, despite the 5x significance factor? Cc @nnethercote |
Yes, those two tests keep bouncig back and forth with exactly 1.3% improvements/regressions |
So I guess we can remove the check_alignment Boolean entirely? |
No, we still need it to be and for interning |
OK. Do we have any tests that were passing and now are failing or is it all just diagnostic changes? |
Blessing the tests locally now to check that. We also need a crater run since this is a breaking change. In fact it's the kind of change where last time we said it'd be kind of nice to have future-incompat warnings first... but I don't know whether or when I will have the time to implement those. @craterbot check |
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I can do that |
Sounds good. :) Let met get CI green for this PR, then you can take over. |
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@bors r=oli-obk,RalfJung |
☀️ Test successful - checks-actions |
Finished benchmarking commit (4954a7e): comparison URL. Overall result: no relevant changes - no action needed@rustbot label: -perf-regression Instruction countThis benchmark run did not return any relevant results for this metric. Max RSS (memory usage)ResultsThis 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.
CyclesThis benchmark run did not return any relevant results for this metric. |
…alfJung always check alignment during CTFE We originally disabled alignment checks because they got in the way -- there are some things we do with the interpreter during CTFE which does not correspond to actually running user-written code, but is purely administrative, and we didn't want alignment checks there, so we just disabled them entirely. But with `-Zextra-const-ub-checks` we anyway had to figure out how to disable those alignment checks while doing checks in regular code. So now it is easy to enable CTFE alignment checking by default. Let's see what the perf consequences of that are. r? `@oli-obk`
Pkgsrc changes: * Adjust patches and cargo checksums to new versions. Upstream changes: Version 1.68.0 (2023-03-09) =========================== Language -------- - [Stabilize default_alloc_error_handler] (rust-lang/rust#102318) This allows usage of `alloc` on stable without requiring the definition of a handler for allocation failure. Defining custom handlers is still unstable. - [Stabilize `efiapi` calling convention.] (rust-lang/rust#105795) - [Remove implicit promotion for types with drop glue] (rust-lang/rust#105085) Compiler -------- - [Change `bindings_with_variant_name` to deny-by-default] (rust-lang/rust#104154) - [Allow .. to be parsed as let initializer] (rust-lang/rust#105701) - [Add `armv7-sony-vita-newlibeabihf` as a tier 3 target] (rust-lang/rust#105712) - [Always check alignment during compile-time const evaluation] (rust-lang/rust#104616) - [Disable "split dwarf inlining" by default.] (rust-lang/rust#106709) - [Add vendor to Fuchsia's target triple] (rust-lang/rust#106429) - [Enable sanitizers for s390x-linux] (rust-lang/rust#107127) Libraries --------- - [Loosen the bound on the Debug implementation of Weak.] (rust-lang/rust#90291) - [Make `std::task::Context` !Send and !Sync] (rust-lang/rust#95985) - [PhantomData layout guarantees] (rust-lang/rust#104081) - [Don't derive Debug for `OnceWith` & `RepeatWith`] (rust-lang/rust#104163) - [Implement DerefMut for PathBuf] (rust-lang/rust#105018) - [Add O(1) `Vec -> VecDeque` conversion guarantee] (rust-lang/rust#105128) - [Leak amplification for peek_mut() to ensure BinaryHeap's invariant is always met] (rust-lang/rust#105851) Stabilized APIs --------------- - [`{core,std}::pin::pin!`] (https://doc.rust-lang.org/stable/std/pin/macro.pin.html) - [`impl From<bool> for {f32,f64}`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#impl-From%3Cbool%3E-for-f32) - [`std::path::MAIN_SEPARATOR_STR`] (https://doc.rust-lang.org/stable/std/path/constant.MAIN_SEPARATOR_STR.html) - [`impl DerefMut for PathBuf`] (https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-DerefMut-for-PathBuf) These APIs are now stable in const contexts: - [`VecDeque::new`] (https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.new) Cargo ----- - [Stabilize sparse registry support for crates.io] (rust-lang/cargo#11224) - [`cargo build --verbose` tells you more about why it recompiles.] (rust-lang/cargo#11407) - [Show progress of crates.io index update even `net.git-fetch-with-cli` option enabled] (rust-lang/cargo#11579) Misc ---- Compatibility Notes ------------------- - [Add `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` to future-incompat report] (rust-lang/rust#103418) - [Only specify `--target` by default for `-Zgcc-ld=lld` on wasm] (rust-lang/rust#101792) - [Bump `IMPLIED_BOUNDS_ENTAILMENT` to Deny + ReportNow] (rust-lang/rust#106465) - [`std::task::Context` no longer implements Send and Sync] (rust-lang/rust#95985) nternal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Encode spans relative to the enclosing item] (rust-lang/rust#84762) - [Don't normalize in AstConv] (rust-lang/rust#101947) - [Find the right lower bound region in the scenario of partial order relations] (rust-lang/rust#104765) - [Fix impl block in const expr] (rust-lang/rust#104889) - [Check ADT fields for copy implementations considering regions] (rust-lang/rust#105102) - [rustdoc: simplify JS search routine by not messing with lev distance] (rust-lang/rust#105796) - [Enable ThinLTO for rustc on `x86_64-pc-windows-msvc`] (rust-lang/rust#103591) - [Enable ThinLTO for rustc on `x86_64-apple-darwin`] (rust-lang/rust#103647)
Pkgsrc changes: * Adjust patches (add & remove) and cargo checksums to new versions. * It's conceivable that the workaround for LLVM based NetBSD works even less in this version (ref. PKGSRC_HAVE_LIBCPP not having a corresponding patch anymore). Upstream changes: Version 1.68.2 (2023-03-28) =========================== - [Update the GitHub RSA host key bundled within Cargo] (rust-lang/cargo#11883). The key was [rotated by GitHub] (https://github.blog/2023-03-23-we-updated-our-rsa-ssh-host-key/) on 2023-03-24 after the old one leaked. - [Mark the old GitHub RSA host key as revoked] (rust-lang/cargo#11889). This will prevent Cargo from accepting the leaked key even when trusted by the system. - [Add support for `@revoked` and a better error message for `@cert-authority` in Cargo's SSH host key verification] (rust-lang/cargo#11635) Version 1.68.1 (2023-03-23) =========================== - [Fix miscompilation in produced Windows MSVC artifacts] (rust-lang/rust#109094) This was introduced by enabling ThinLTO for the distributed rustc which led to miscompilations in the resulting binary. Currently this is believed to be limited to the -Zdylib-lto flag used for rustc compilation, rather than a general bug in ThinLTO, so only rustc artifacts should be affected. - [Fix --enable-local-rust builds] (rust-lang/rust#109111) - [Treat `$prefix-clang` as `clang` in linker detection code] (rust-lang/rust#109156) - [Fix panic in compiler code] (rust-lang/rust#108162) Version 1.68.0 (2023-03-09) =========================== Language -------- - [Stabilize default_alloc_error_handler] (rust-lang/rust#102318) This allows usage of `alloc` on stable without requiring the definition of a handler for allocation failure. Defining custom handlers is still unstable. - [Stabilize `efiapi` calling convention.] (rust-lang/rust#105795) - [Remove implicit promotion for types with drop glue] (rust-lang/rust#105085) Compiler -------- - [Change `bindings_with_variant_name` to deny-by-default] (rust-lang/rust#104154) - [Allow .. to be parsed as let initializer] (rust-lang/rust#105701) - [Add `armv7-sony-vita-newlibeabihf` as a tier 3 target] (rust-lang/rust#105712) - [Always check alignment during compile-time const evaluation] (rust-lang/rust#104616) - [Disable "split dwarf inlining" by default.] (rust-lang/rust#106709) - [Add vendor to Fuchsia's target triple] (rust-lang/rust#106429) - [Enable sanitizers for s390x-linux] (rust-lang/rust#107127) Libraries --------- - [Loosen the bound on the Debug implementation of Weak.] (rust-lang/rust#90291) - [Make `std::task::Context` !Send and !Sync] (rust-lang/rust#95985) - [PhantomData layout guarantees] (rust-lang/rust#104081) - [Don't derive Debug for `OnceWith` & `RepeatWith`] (rust-lang/rust#104163) - [Implement DerefMut for PathBuf] (rust-lang/rust#105018) - [Add O(1) `Vec -> VecDeque` conversion guarantee] (rust-lang/rust#105128) - [Leak amplification for peek_mut() to ensure BinaryHeap's invariant is always met] (rust-lang/rust#105851) Stabilized APIs --------------- - [`{core,std}::pin::pin!`] (https://doc.rust-lang.org/stable/std/pin/macro.pin.html) - [`impl From<bool> for {f32,f64}`] (https://doc.rust-lang.org/stable/std/primitive.f32.html#impl-From%3Cbool%3E-for-f32) - [`std::path::MAIN_SEPARATOR_STR`] (https://doc.rust-lang.org/stable/std/path/constant.MAIN_SEPARATOR_STR.html) - [`impl DerefMut for PathBuf`] (https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-DerefMut-for-PathBuf) These APIs are now stable in const contexts: - [`VecDeque::new`] (https://doc.rust-lang.org/stable/std/collections/struct.VecDeque.html#method.new) Cargo ----- - [Stabilize sparse registry support for crates.io] (rust-lang/cargo#11224) - [`cargo build --verbose` tells you more about why it recompiles.] (rust-lang/cargo#11407) - [Show progress of crates.io index update even `net.git-fetch-with-cli` option enabled] (rust-lang/cargo#11579) Misc ---- Compatibility Notes ------------------- - [Add `SEMICOLON_IN_EXPRESSIONS_FROM_MACROS` to future-incompat report] (rust-lang/rust#103418) - [Only specify `--target` by default for `-Zgcc-ld=lld` on wasm] (rust-lang/rust#101792) - [Bump `IMPLIED_BOUNDS_ENTAILMENT` to Deny + ReportNow] (rust-lang/rust#106465) - [`std::task::Context` no longer implements Send and Sync] (rust-lang/rust#95985) nternal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Encode spans relative to the enclosing item] (rust-lang/rust#84762) - [Don't normalize in AstConv] (rust-lang/rust#101947) - [Find the right lower bound region in the scenario of partial order relations] (rust-lang/rust#104765) - [Fix impl block in const expr] (rust-lang/rust#104889) - [Check ADT fields for copy implementations considering regions] (rust-lang/rust#105102) - [rustdoc: simplify JS search routine by not messing with lev distance] (rust-lang/rust#105796) - [Enable ThinLTO for rustc on `x86_64-pc-windows-msvc`] (rust-lang/rust#103591) - [Enable ThinLTO for rustc on `x86_64-apple-darwin`] (rust-lang/rust#103647) Version 1.67.0 (2023-01-26) ========================== Language -------- - [Make `Sized` predicates coinductive, allowing cycles.] (rust-lang/rust#100386) - [`#[must_use]` annotations on `async fn` also affect the `Future::Output`.] (rust-lang/rust#100633) - [Elaborate supertrait obligations when deducing closure signatures.] (rust-lang/rust#101834) - [Invalid literals are no longer an error under `cfg(FALSE)`.] (rust-lang/rust#102944) - [Unreserve braced enum variants in value namespace.] (rust-lang/rust#103578) Compiler -------- - [Enable varargs support for calling conventions other than `C` or `cdecl`.] (rust-lang/rust#97971) - [Add new MIR constant propagation based on dataflow analysis.] (rust-lang/rust#101168) - [Optimize field ordering by grouping m\*2^n-sized fields with equivalently aligned ones.] (rust-lang/rust#102750) - [Stabilize native library modifier `verbatim`.] (rust-lang/rust#104360) Added and removed targets: - [Add a tier 3 target for PowerPC on AIX] (rust-lang/rust#102293), `powerpc64-ibm-aix`. - [Add a tier 3 target for the Sony PlayStation 1] (rust-lang/rust#102689), `mipsel-sony-psx`. - [Add tier 3 `no_std` targets for the QNX Neutrino RTOS] (rust-lang/rust#102701), `aarch64-unknown-nto-qnx710` and `x86_64-pc-nto-qnx710`. - [Remove tier 3 `linuxkernel` targets] (rust-lang/rust#104015) (not used by the actual kernel). Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. Libraries --------- - [Merge `crossbeam-channel` into `std::sync::mpsc`.] (rust-lang/rust#93563) - [Fix inconsistent rounding of 0.5 when formatted to 0 decimal places.] (rust-lang/rust#102935) - [Derive `Eq` and `Hash` for `ControlFlow`.] (rust-lang/rust#103084) - [Don't build `compiler_builtins` with `-C panic=abort`.] (rust-lang/rust#103786) Stabilized APIs --------------- - [`{integer}::checked_ilog`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog) - [`{integer}::checked_ilog2`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog2) - [`{integer}::checked_ilog10`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.checked_ilog10) - [`{integer}::ilog`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog) - [`{integer}::ilog2`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog2) - [`{integer}::ilog10`] (https://doc.rust-lang.org/stable/std/primitive.i32.html#method.ilog10) - [`NonZeroU*::ilog2`] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#method.ilog2) - [`NonZeroU*::ilog10`] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#method.ilog10) - [`NonZero*::BITS`] (https://doc.rust-lang.org/stable/std/num/struct.NonZeroU32.html#associatedconstant.BITS) These APIs are now stable in const contexts: - [`char::from_u32`] (https://doc.rust-lang.org/stable/std/primitive.char.html#method.from_u32) - [`char::from_digit`] (https://doc.rust-lang.org/stable/std/primitive.char.html#method.from_digit) - [`char::to_digit`] (https://doc.rust-lang.org/stable/std/primitive.char.html#method.to_digit) - [`core::char::from_u32`] (https://doc.rust-lang.org/stable/core/char/fn.from_u32.html) - [`core::char::from_digit`] (https://doc.rust-lang.org/stable/core/char/fn.from_digit.html) Compatibility Notes ------------------- - [The layout of `repr(Rust)` types now groups m\*2^n-sized fields with equivalently aligned ones.] (rust-lang/rust#102750) This is intended to be an optimization, but it is also known to increase type sizes in a few cases for the placement of enum tags. As a reminder, the layout of `repr(Rust)` types is an implementation detail, subject to change. - [0.5 now rounds to 0 when formatted to 0 decimal places.] (rust-lang/rust#102935) This makes it consistent with the rest of floating point formatting that rounds ties toward even digits. - [Chains of `&&` and `||` will now drop temporaries from their sub-expressions in evaluation order, left-to-right.] (rust-lang/rust#103293) Previously, it was "twisted" such that the _first_ expression dropped its temporaries _last_, after all of the other expressions dropped in order. - [Underscore suffixes on string literals are now a hard error.] (rust-lang/rust#103914) This has been a future-compatibility warning since 1.20.0. - [Stop passing `-export-dynamic` to `wasm-ld`.] (rust-lang/rust#105405) - [`main` is now mangled as `__main_void` on `wasm32-wasi`.] (rust-lang/rust#105468) - [Cargo now emits an error if there are multiple registries in the configuration with the same index URL.] (rust-lang/cargo#10592) Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Rewrite LLVM's archive writer in Rust.] (rust-lang/rust#97485)
const-eval: make misalignment a hard error It's been a future-incompat error (showing up in cargo's reports) since rust-lang#104616, Rust 1.68, released in March. That should be long enough. The question for the lang team is simply -- should we move ahead with this, making const-eval alignment failures a hard error? (It turns out some of them accidentally already were hard errors since rust-lang#104616. But not all so this is still a breaking change. Crater found no regression.)
const-eval: make misalignment a hard error It's been a future-incompat error (showing up in cargo's reports) since rust-lang/rust#104616, Rust 1.68, released in March. That should be long enough. The question for the lang team is simply -- should we move ahead with this, making const-eval alignment failures a hard error? (It turns out some of them accidentally already were hard errors since #104616. But not all so this is still a breaking change. Crater found no regression.)
We originally disabled alignment checks because they got in the way -- there are some things we do with the interpreter during CTFE which does not correspond to actually running user-written code, but is purely administrative, and we didn't want alignment checks there, so we just disabled them entirely. But with
-Zextra-const-ub-checks
we anyway had to figure out how to disable those alignment checks while doing checks in regular code. So now it is easy to enable CTFE alignment checking by default. Let's see what the perf consequences of that are.r? @oli-obk