Remove avx512dq and avx512vl implication for avx512fp16

[sayantn]

According to Intel, avx512fp16 requires only avx512bw, but LLVM also enables avx512vl and avx512dq when avx512fp16 is active. This is relic code, and will be fixed in LLVM soon. We should remove this from Rust too asap, especially before the stabilization of AVX512

Related:

• [X86] Target feature implication mismatch with GCC llvm/llvm-project#136209
• Stabilize the avx512 target features #138940
• Require fma and f16c for avx512f in std_detect stdarch#1781
• Tracking Issue for AVX512 intrinsics #111137

@rustbot label O-x86_64 O-x86_32 A-SIMD A-target-feature T-compiler -T-libs
r? @Amanieu

Update: the LLVM fix has been merged

cc @rust-lang/wg-llvm will it be possible to update the rustc llvm version to something after llvm/llvm-project#137450

[rustbot]

⚠️ Warning ⚠️

• Some commits in this PR modify submodules.

[sayantn]

cc @a4lg there seems to be some doc errors in the is_riscv_feature_detected macro. Could you look into the pls.

PS: I am quite confused how they weren't caught in the stdarch CI

[sayantn]

On hindsight, this seems like a bug in rustdoc with cg_gcc. Still I am retrying the CI

cc @rust-lang/rustdoc @rust-lang/wg-gcc-backend

edit: not spurious

[a4lg]

@sayantn
That's odd.

It seems the Linkcheck tool on the CI does its own job and the error itself seems valid.

However, multiple references to a single footnote is mandatory for simplicity of the new macro documentation with the platform guide.
And I thought this is allowed. While duplicate ID for footnote references is not ideal (of course) but at least tested in tests/rustdoc/footnote-reference-in-footnote-def.rs which has two duplicate IDs on footnote references to [^a].
So I suppose this is a rustdoc bug to be fixed (give each reference to a footnote unique ID as a long term solution).

If you prefer the short term solution to pass CI, you may revert rust-lang/stdarch#1779.

[a4lg]

I created a rustdoc PR #140434 (implementing it was easier than I thought) to enable adopting rust-lang/stdarch#1779 in the future. I'm not sure whether adoption of this PR will result in immediate success (considering the default stage for building docs (stage 0), it might not be immediate) but I hope this is accepted.

[rust-log-analyzer]

The job x86_64-gnu-llvm-19 failed! Check out the build log: (web) (plain)

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

#18 exporting to docker image format
#18 sending tarball 20.4s done
#18 DONE 27.0s
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Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
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configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-19', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'build.print-step-timings', '--enable-verbose-tests', '--set', 'build.metrics', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--set', 'gcc.download-ci-gcc=true', '--enable-new-symbol-mangling']
configure: build.build          := x86_64-unknown-linux-gnu
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-19/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
[RUSTC-TIMING] proc_macro test:false 5.572
[RUSTC-TIMING] test test:false 9.428
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[TIMING] core::build_steps::compile::Std { target: x86_64-unknown-linux-gnu, compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: true }, crates: [], force_recompile: false, extra_rust_args: ["-Csymbol-mangling-version=v0", "-Cpanic=abort"], is_for_mir_opt_tests: false } -- 78.805
Testing GCC stage1 (x86_64-unknown-linux-gnu -> x86_64-unknown-linux-gnu)
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[RUSTC-TIMING] boml test:false 0.778
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     Running `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-codegen/x86_64-unknown-linux-gnu/release/y test --use-backend gcc --gcc-path /checkout/obj/build/x86_64-unknown-linux-gnu/ci-gcc/lib --out-dir /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_gcc --release --mini-tests --std-tests`
`--gcc-path` was provided, ignoring config file. Using `/checkout/obj/build/x86_64-unknown-linux-gnu/ci-gcc/lib` as path for libgccjit
[BUILD] mini_core
[RUSTC-TIMING] mini_core test:false 0.203
[BUILD] example
[AOT] mini_core_hello_world
[RUSTC-TIMING] mini_core_hello_world test:false 0.182
---
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[TIMING] core::build_steps::tool::ToolBuild { compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu, tool: "linkchecker", path: "src/tools/linkchecker", mode: ToolBootstrap, source_type: InTree, extra_features: [], allow_features: "", cargo_args: [], artifact_kind: Binary } -- 0.141
[TIMING] core::build_steps::tool::Linkchecker { compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu } -- 0.000
##[group]Testing stage0 Linkcheck (x86_64-unknown-linux-gnu)
std/arch/macro.is_riscv_feature_detected.html:115: id is not unique: `fnref1`
std/arch/macro.is_riscv_feature_detected.html:118: id is not unique: `fnref1`
std/arch/macro.is_riscv_feature_detected.html:123: id is not unique: `fnref1`
std/arch/macro.is_riscv_feature_detected.html:126: id is not unique: `fnref1`
std/arch/macro.is_riscv_feature_detected.html:128: id is not unique: `fnref1`
std/arch/macro.is_riscv_feature_detected.html:128: id is not unique: `fnref2`
std/arch/macro.is_riscv_feature_detected.html:137: id is not unique: `fnref2`
std/arch/macro.is_riscv_feature_detected.html:138: id is not unique: `fnref2`
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std/arch/macro.is_riscv_feature_detected.html:174: id is not unique: `fnref2`
std/arch/macro.is_riscv_feature_detected.html:175: id is not unique: `fnref2`
checked links in: 25.1s
number of HTML files scanned: 45810
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number of links ignored due to external: 102531
number of links ignored due to exceptions: 24
number of intra doc links ignored: 9
errors found: 19
found some broken links
Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:38:55
  local time: Tue Apr 29 15:26:16 UTC 2025
  network time: Tue, 29 Apr 2025 15:26:16 GMT
##[error]Process completed with exit code 1.
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[a4lg]

I opened a PR rust-lang/stdarch#1792 that will revert rust-lang/stdarch#1779 for now. If this PR is applied, stdarch should be safely merged into the master branch.

Even if #140434 is merged now, because the CI failure says this is caused by the stage0 compiler, we have to wait the next beta to merge rust-lang/stdarch#1779.