simd_reduce_min/max: remove float support by RalfJung · Pull Request #155189 · rust-lang/rust

RalfJung · 2026-04-12T08:50:14Z

LLVM currently doesn't have an intrinsic with the right semantics here (see llvm/llvm-project#185827). The only remaining user of this intrinsic with float types is portable-simd and it's easier to implement a fallback there than here, so I opted for making the intrinsic int-only. I kept around the float support in cranelift and Miri because there it already has the desired semantics (matching scalar min/max).

Fixes#153395
~~Blocked on rust-lang/portable-simd#515~~

rustbot · 2026-04-12T08:50:17Z

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

Some changes occurred to the platform-builtins intrinsics. Make sure the
LLVM backend as well as portable-simd gets adapted for the changes.

cc @antoyo, @GuillaumeGomez, @bjorn3, @calebzulawski, @programmerjake

Some changes occurred to the intrinsics. Make sure the CTFE / Miri interpreter
gets adapted for the changes, if necessary.

cc @rust-lang/miri, @oli-obk, @lcnr

rustbot · 2026-04-12T08:50:19Z

r? @chenyukang

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chenyukang · 2026-04-12T09:36:55Z

this need to change?
https://github.com/chenyukang/rust/blob/d7ab69561a799848e3f7ca6671ab6671b92475f6/library/portable-simd/crates/core_simd/src/simd/num/float.rs#L431-L441

chenyukang · 2026-04-12T09:38:18Z

need more reviewers from the domain
@rustbot reroll

RalfJung · 2026-04-12T10:18:57Z

this need to change? https://github.com/chenyukang/rust/blob/d7ab69561a799848e3f7ca6671ab6671b92475f6/library/portable-simd/crates/core_simd/src/simd/num/float.rs#L431-L441

Yeah as I said this is blocked on rust-lang/portable-simd#515.

RalfJung · 2026-04-26T12:27:09Z

@calebzulawski any chance we could get a portable-simd sync so that this PR can make progress? :)

RalfJung · 2026-04-28T13:48:19Z

Or maybe @folkertdev you could help us out with a sync here? Looks like you've done one before. :)

folkertdev · 2026-04-28T14:53:08Z

I opened rust-lang/portable-simd#525, but we'll need someone to merge it.

Unless you meant a sync the other way? But that doesn't do anything currently.

RalfJung · 2026-04-28T15:02:36Z

Yes I meant a sync the other way. That should sync rust-lang/portable-simd#515, which was not part of the previous sync. So it should definitely do something.

calebzulawski · 2026-04-28T15:10:26Z

Sorry, I've been swamped with some other things. If you can open the sync the other way I can review it, otherwise I should be able to get around to it in the next few days

folkertdev · 2026-04-28T15:20:04Z

The sync script is very sensitive to the current state of your local branches, turns out. Anyhow:

#155930

rustbot · 2026-04-29T11:48:54Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

RalfJung · 2026-04-29T11:56:52Z

@petrochenkov this is unblocked now. :)
@rustbot ready

petrochenkov · 2026-04-29T12:31:56Z

@bors r+

rust-bors · 2026-04-29T12:31:59Z

📌 Commit ad7ddbc has been approved by petrochenkov

It is now in the queue for this repository.

…trochenkov simd_reduce_min/max: remove float support LLVM currently doesn't have an intrinsic with the right semantics here (see llvm/llvm-project#185827). The only remaining user of this intrinsic with float types is portable-simd and it's easier to implement a fallback there than here, so I opted for making the intrinsic int-only. I kept around the float support in cranelift and Miri because there it already has the desired semantics (matching scalar min/max). Fixesrust-lang#153395 ~~Blocked on rust-lang/portable-simd#515

…uwer Rollup of 12 pull requests Successful merges: - #155189 (simd_reduce_min/max: remove float support) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.)

…trochenkov simd_reduce_min/max: remove float support LLVM currently doesn't have an intrinsic with the right semantics here (see llvm/llvm-project#185827). The only remaining user of this intrinsic with float types is portable-simd and it's easier to implement a fallback there than here, so I opted for making the intrinsic int-only. I kept around the float support in cranelift and Miri because there it already has the desired semantics (matching scalar min/max). Fixesrust-lang#153395 ~~Blocked on rust-lang/portable-simd#515

…uwer Rollup of 22 pull requests Successful merges: - #154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - #155189 (simd_reduce_min/max: remove float support) - #155453 (apply Cortex-A53 errata 843419 mitigation to the AArch64 Linux targets) - #155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - #155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155832 (c-variadic: more precise compatibility check in const-eval) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155966 (miri subtree update) - #155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - #155831 (Add `AcceptContext::expect_key_value`) - #155877 (Avoid misleading return-type note for foreign `Fn` callees) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - #155967 (Fix `doc_cfg` feature for extern items)

…uwer Rollup of 21 pull requests Successful merges: - #155966 (miri subtree update) - #154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - #155189 (simd_reduce_min/max: remove float support) - #155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - #155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - #155721 (When archive format is wrong produce an error instead of ICE) - #155794 (privacy: share effective visibility initialization) - #155832 (c-variadic: more precise compatibility check in const-eval) - #155856 (std_detect: support detecting more features on aarch64 Windows) - #155861 (Suggest `[const] Trait` bounds in more places) - #155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - #155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - #155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - #155950 (use the new `//@ needs-asm-mnemonic: ret` more) - #155958 (ci(free-disk-space): remove more tools and fix warnings) - #155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - #155831 (Add `AcceptContext::expect_key_value`) - #155877 (Avoid misleading return-type note for foreign `Fn` callees) - #155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - #155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - #155967 (Fix `doc_cfg` feature for extern items)

Rollup merge of #155189 - RalfJung:reduce-minmax-float, r=petrochenkov simd_reduce_min/max: remove float support LLVM currently doesn't have an intrinsic with the right semantics here (see llvm/llvm-project#185827). The only remaining user of this intrinsic with float types is portable-simd and it's easier to implement a fallback there than here, so I opted for making the intrinsic int-only. I kept around the float support in cranelift and Miri because there it already has the desired semantics (matching scalar min/max). Fixes#153395 ~~Blocked on rust-lang/portable-simd#515

…uwer Rollup of 21 pull requests Successful merges: - rust-lang/rust#155966 (miri subtree update) - rust-lang/rust#154149 (resolve: Extend `ambiguous_import_visibilities` deprecation lint to glob-vs-glob ambiguities) - rust-lang/rust#155189 (simd_reduce_min/max: remove float support) - rust-lang/rust#155562 (Add a missing `GenericTypeVisitable`, and avoid having interner traits for `FnSigKind` and `Abi`) - rust-lang/rust#155608 (rustc_middle: Implement the `partial_cmp` operation for `DefId`s) - rust-lang/rust#155721 (When archive format is wrong produce an error instead of ICE) - rust-lang/rust#155794 (privacy: share effective visibility initialization) - rust-lang/rust#155832 (c-variadic: more precise compatibility check in const-eval) - rust-lang/rust#155856 (std_detect: support detecting more features on aarch64 Windows) - rust-lang/rust#155861 (Suggest `[const] Trait` bounds in more places) - rust-lang/rust#155899 (`dlltool`: Set the working directory to workaround `--temp-prefix` bug) - rust-lang/rust#155916 (Update with new LLVM 22 target for `wasm32-wali-linux-musl` target) - rust-lang/rust#155935 (remap OUT_DIR paths to fix build script path leakage in crate metadata. ) - rust-lang/rust#155950 (use the new `//@ needs-asm-mnemonic: ret` more) - rust-lang/rust#155958 (ci(free-disk-space): remove more tools and fix warnings) - rust-lang/rust#155711 (bump curl-sys and openssl-sys to support OpenSSL 4.0.x) - rust-lang/rust#155831 (Add `AcceptContext::expect_key_value`) - rust-lang/rust#155877 (Avoid misleading return-type note for foreign `Fn` callees) - rust-lang/rust#155949 (Update `opt_ast_lowering_delayed_lints` query to allow "stealing" lints, allowing to use `FnOnce` instead of `Fn`) - rust-lang/rust#155951 (Make `FlatMapInPlaceVec` an unsafe trait.) - rust-lang/rust#155967 (Fix `doc_cfg` feature for extern items)

rustbot assigned chenyukang Apr 12, 2026

RalfJung commented Apr 12, 2026
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Comment threadcompiler/rustc_codegen_gcc/src/builder.rs

chenyukang reviewed Apr 12, 2026
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Comment threadlibrary/core/src/intrinsics/simd/mod.rs

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rustbot assigned petrochenkov and unassigned chenyukang Apr 12, 2026

RalfJung force-pushed the reduce-minmax-float branch 2 times, most recently from 1df099e to c77f465Compare April 12, 2026 10:20

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petrochenkov added S-blocked Status: Blocked on something else such as an RFC or other implementation work. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Apr 13, 2026

simd_reduce_min/max: remove float support
ad7ddbc

RalfJung force-pushed the reduce-minmax-float branch from c77f465 to ad7ddbcCompare April 29, 2026 11:48

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-blocked Status: Blocked on something else such as an RFC or other implementation work. labels Apr 29, 2026

rust-borsBot 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 Apr 29, 2026

JonathanBrouwer mentioned this pull request Apr 29, 2026
Rollup of 12 pull requests #155964
Closed

JonathanBrouwer mentioned this pull request Apr 29, 2026
Rollup of 22 pull requests #155976
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JonathanBrouwer mentioned this pull request Apr 29, 2026
Rollup of 21 pull requests #155979
Merged

rust-borsBot merged commit cda4395 into rust-lang:mainApr 30, 2026
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rustbot added this to the 1.97.0 milestone Apr 30, 2026

RalfJung deleted the reduce-minmax-float branch May 2, 2026 08:57

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